Chemical characteristics and colorimetric properties of non-centrifugal cane sugar (“panela”) obtained via different processing technologies

Elsevier Editorial System(tm) for Food Chemistry or its open access mirror Manuscript Draft Manuscript Number: FOODCHEM-D-20-05046R1 Title: Chemical characteristics and colorimetric properties of noncentrifugal cane sugar ("panela") obtained via different processing technologies Article Type: Research Article (max 7,500 words) Keywords: Panela; jaggery; spray drying; phenolic compounds; phenolic acids, colour parameters. Corresponding Author: Professor Alvaro Orjuela, PhD. Corresponding Author's Institution: Universidad Nacional de Colombia First Author: Ángela L Alarcón, MSc. Order of Authors: Ángela L Alarcón, MSc.; Laura M Palacios, PhD; Coralia Osorio, PhD; Paulo C Narvaez, PhD; Francisco J Heredia, PhD; Alvaro Orjuela, PhD.; Dolores Hernanz, PhD Abstract: Non-centrifugal cane sugar (NCS) samples obtained by traditional moulding and granulation, and also via a novel spray-drying powdering process without additives, were assessed to characterise their sugar and phenolic profiles, flavonoid content, as well as colour parameters. As expected, sucrose was the predominant sugar (91.9 - 95.5%), followed by glucose (2.9-4.6%), and fructose (1.6-3.7%). Total phenolic content was between 0.4-0.6% and total flavonoid content into the range of 0.2-0.4%. Six phenolic acids were found in all NCS samples: protocatechuic acid (0.36-0.94 µg/100 g), vanillic acid (0.70-1.45 µg/100 g), chlorogenic acid (2.08-3.82 µg/100 g), syringic acid (1.08-2.80 µg/100 g), p-coumaric acid (0.69-1.35 µg/100 g), and ferulic acid (0.50- 0.95 µg/100 g). The thermal treatment under high temperatures required in the production of granulated products was related with darker colours and changes in phenol and flavonoid contents. In contrast, spray drying generates clearer products, but with slightly less phenol and flavonoid contents. 1 Chemical characteristics and colorimetric properties of non-centrifugal 1 cane sugar (“panela”) obtained via different processing technologies 2 3 Angela L. Alarcón,a Laura M. Palacios,a Coralia Osorio,b Paulo César Narváez,a 4 Francisco J. Heredia,c Alvaro Orjuela,a* and Dolores Hernanzd 5 6 a Department of Chemical and Environmental Engineering, Universidad Nacional de 7 Colombia, 111321 Bogotá D.C., Colombia 8 b Departamento de Química, , 9 Colombia 10 c Food Colour & Quality Lab., Facultad de Farmacia, Universidad de Sevilla, 41012 11 Sevilla, Spain 12 d Department of Analytical Chemistry, Facultad de Farmacia, Universidad de Sevilla, 13 41012 Sevilla, Spain 14 15 16 Abbreviated running header: Chemical characterization of non-centrifugal cane sugar under 17 different processing 18 19 * Correspondence to: Alvaro Orjuela, tel.: + 57-1-3165000, ext. 14303; e-mail: 20 [email protected] 21 *Manuscript Click here to download Manuscript: Corrected manuscript.docx 2 Abstract 22 23 Non-centrifugal cane sugar (NCS) samples obtained by traditional moulding and 24 granulation, and also via a novel spray-drying powdering process without additives, were 25 assessed to characterise their sugar and phenolic profiles, flavonoid content, as well as 26 colour parameters. As expected, sucrose was the predominant sugar (91.9 – 95.5%), 27 followed by glucose (2.9-4.6%), and fructose (1.6-3.7%). Total phenolic content was 28 between 0.4-0.6% and total flavonoid content into the range of 0.2-0.4%. Six phenolic acids 29 were found in all NCS samples: protocatechuic acid (0.36-0.94 µg/100 g), vanillic acid 30 (0.70-1.45 µg/100 g), chlorogenic acid (2.08-3.82 µg/100 g), syringic acid (1.08-2.80 31 µg/100 g), p-coumaric acid (0.69-1.35 µg/100 g), and ferulic acid (0.50-0.95 µg/100 g). 32 The thermal treatment under high temperatures required in the production of granulated 33 products was related with darker colours and changes in phenol and flavonoid contents. In 34 contrast, spray drying generates clearer products, but with slightly less phenol and 35 flavonoid contents. 36 37 Keywords: Panela; jaggery; spray drying; phenolic compounds; phenolic acids, colour 38 parameters. 39 Chemical compounds studied in this article: Protocatechuic acid (PubChem CID: 528594); 40 vanillic acid (PubChem CID: 8468); chlorogenic acid (PubChem CID: 1794427); syringic 41 acid (PubChem CID: 10742); p-coumaric acid (PubChem CID: 637542); ferulic acid 42 (PubChem CID: 445858); sucrose (PubChem CID: 5988); glucose (PubChem CID: 5793); 43 fructose (PubChem CID: 2723872). 44 3 45 4 1. Introduction 46 47 Panela, jaggery, gur, muscovado, or piloncillo is a natural sweetener obtained by 48 concentration of sugar cane juices (Saccharum officinarum), technically known as non-49 centrifugal cane sugar (NCS). According to the Food and Agriculture Organization of the 50 United Nations (FAO), the NCS is more than a sweetener (Jaffé, 2015), and it can be 51 considered as a whole food product of high nutritional value. Additionally, NCS is an 52 advantageous substitute of white sugar, because its minimal chemical processing enables to 53 retain a variety of minerals (Fe, Ca, P, K, Mg, Cu, Mn, Na, and Zn), vitamins (A, C, and 54 D), carbohydrates (sucrose, glucose, and fructose), antioxidant substances, and other 55 phytochemicals from sugar cane (Duarte-Almeida, Salatino, Genovese & Lajolo, 2011; 56 Harish Nayaka, Sathisha, Manohar, Chandrashekar & Dharmesh, 2009; Feng, Luo, Zhang, 57 Zhong, & Lu, 2014; Jaffé, 2015; Seguí, Calabuig-Jiménez, Betoret & Fito, 2015; Arif, 58 Batool, Nazir, Khan, & Khalid 2019). The presence of these compounds gives NCS some 59 functional properties, such as the ability to reduce the cells degenerative processes and to 60 mitigate problems associated to cancer and cardiovascular diseases (Harish Nayaka, 61 Sathisha, Manohar, Chandrashekar & Dharmesh, 2009). Also, NCS has been used to reduce 62 the negative effects of some infections and diseases such as bronchitis, cough, anaemia, and 63 jaundice (Seguí, Calabuig-Jiménez, Betoret & Fito, 2015). 64 65 Nowadays, world NCS production is around 12000 kt/yr. and the largest producers are 66 India (60%), Colombia (14.9%), Pakistan (5%), China (3.9%), and Brazil (3.7%) 67 (Minagricultura, 2018). Nevertheless, it is consumed worldwide as sweetener or as 68 ingredient in different food products and beverages (Lamdande, Khabeer, Kulathooran, & 69 5 Dasappa, 2018; Mohan & Agrawal, 2020). Particularly in Colombia, the production of 70 NCS is a traditional artisan activity with a strong economic and social significance. This 71 productive sector generates around 1.2 million jobs, mainly in rural areas, and the country 72 has the highest world per capita consumption (Minagricultura, 2018). 73 74 The traditional production of NCS is mostly an artisan activity, and it begins with the 75 extraction of sugar-rich juices from sugar cane in a compression mill. Then the juices are 76 heated up to carry out the clarification process by adding a natural mucilage as coagulant 77 agent. Afterwards, the clarified solution is subjected to alkalisation with lime to adjust pH 78 nearly to 6.0, in order to avoid sucrose hydrolysis. Subsequently, juices are concentrated by 79 an open evaporation process, generating intermediate sugar solutions generally called sugar 80 cane syrups (solutions from 50 to 80 °Brix). The evaporation process ends when the 81 solution is concentrated to 90–92 °Brix, or even at higher concentrations when the product 82 is intended for granulation. Finally, the concentrated liquid is stirred to induce crystals 83 formation (Verma, Iyer, Shah, & Mahajani, 2021) and cooled down in moulds to obtain 84 NCS blocks or bricks (Alarcón, Orjuela, Narváez & Camacho, 2020). 85 86 The solid bricks are the most common commercial forms of NCS because their regular 87 shapes are convenient for piling, storage, packaging, and transportation, as well as to 88 minimize water sorption. However, NCS bricks lack convenience for consumers because 89 there is need for product grinding before use, and it exhibits a low dissolution rate at room 90 temperature (18 C). For these reasons, producers have developed granulated products with 91 the aim to enhance the dissolution rate, and making them suitable as instantaneous 92 6 sweeteners (Verma, Shah, & Mahajani, 2019). Current granulation processes involve 93 mechanical milling of the bricks and subsequent sieving. Alternatively, there is a technique 94 that involves the addition of sodium bicarbonate to the concentrated syrup (above 92 95 °Brix). The bicarbonate thermally decomposes above 80 ºC releasing CO2 and causing the 96 product to rise. At the same time, the hot mass is manually shaken with a scrapper until it 97 expands into a sponge-like form. After cooling the porous matrix bursts out generating the 98 granulated solids (Prada Forero, García Bernal & Chaves Guerrero, 2015; Alarcón, Orjuela, 99 Narváez, & Camacho, 2020). Any of these granulation methods increases the processing 100 time and energy consumption, modifies the sensory properties of the final product, and 101 reduces the production capacity in the NCS facilities (Hussain, Islam, Mohammad, 102 Perveen, & Khan, 2011; Solís et al., 2019; Vera, García, Otalvaro, & Mendieta, 2019; 103 Verma, Shah, & Mahajani, 2019). A pictorial image of commercial products is presented in 104 Figure 1S in the supplementary material. 105 106 Recently, some alternative processes have been evaluated to produce powdered NCS 107 with high dissolution rates via spray drying of juices and syrups (Cortes, Ciro, Rodríguez, 108 & Largo, 2012; Khuenpet, Charoenjarasrerk, Jaijit, Arayapoonpong, & Jittanit, 2016; 109 Palacios, Orjuela, Narváez, & Osorio, 2016). Spray drying is widely used in the food 110 industry; however, its adaptation to produce powdered NCS is still a major challenge. The 111 high sugar-content (i.e. sucrose, glucose, and fructose) in NCS’s syrups can cause troubles 112 during the drying process (e.g. filaments formation, caking/sticking of solids) due to the 113 low glass transition temperatures of the dried materials as a result of their hygroscopic 114 nature (Truong, Bhandari & Howes, 2005). Also, because this powdering method involves 115 contact with air at high temperatures, chemical, and sensory properties might be affected by 116 7 potential oxidation, thermal degradation, or volatile losses. Nevertheless, if spray drying 117 challenges can be overcome, this technique could boost NCS production and demand 118 mainly in the food industry. 119 120 In this regard, the aim of this work was to develop a chemical characterisation and a 121 comparative assessment of the NCS samples obtained by using different technologies, 122 namely traditional moulding in blocks, granulation, and powdering via spray-drying. As 123 part of their characterisation, the sugar profile, total phenolic and flavonoid content, as well 124 as the profile of phenolic compounds of different NCS samples were determined. 125 Thereafter, these properties were correlated with colour measurements. Furthermore, 126 granulated and powdered NCS were analysed into the different particle sizes to verify 127 composition homogeneity and to rule out the potential chemical stratification. The 128 hypothesis behind this study was that the spray drying process would produce an equivalent 129 NCS product (i.e. chemical compounds and colour) to those currently commercialized in 130 the market (i.e. bricks and granules) but with improved preservation of nutritional 131 compounds. 132 133 2. Materials and methods 134 135 2.1. Samples collection and/or preparation 136 137 Four types of NCS samples were studied, all of them obtained from producers in the 138 state of Cundinamarca, Colombia. The traditional NCS bricks (NCS-B) were purchased at 139 local store and corresponded to the brand Megapanela® (Pane-rapid Ltd.). The granulated 140 8 NCS (NCS-G) and syrups of 50 °Brix (S50) and 70 °Brix (S70) were acquired in a 141 manufacturing facility located at SENA (Tobia, Cundinamarca, Colombia). Powdered NCS 142 (NCS-P50 and NCS-P70) was obtained by spray drying of collected syrups (i.e. S50 and 143 S70) without the use of additives. These syrups were collected from the same batch used 144 for granulated NCS production at the SENA facilities, and they were stored in autoclaved 145 and sterilized glass bottles (schott®), and maintained under refrigerated conditions prior use 146 or characterization (max. 1 month). For that purpose, a LabPlant SD-06 (Huddersfield, UK) 147 laboratory-scale (1110 mm x 825 mm x 600 mm main spray chamber) spray dryer was 148 used. Approximately, 1 L of the feed-mixture (i.e. 50 or 70 °Brix) was kept at 40 ºC, and 149 spray dried with a hot air flow of 3 kg/h, by using a 0.5 mm diameter nozzle. The feed flow 150 was 0.597 kg/h, and the inlet and outlet air temperatures were 140 ± 2 ºC, and 65 ± 2 ºC, 151 respectively (Palacios, Orjuela, Narváez & Osorio, 2016). The NCS-P was collected from 152 the cyclone. The final solid (NCS-B, NCS-G, NCS-P50 and NCS-P70) and liquid (S50 and 153 S70) samples were collected and stored in hermetic containers for further characterisation. 154 A picture of the assessed samples is presented in figure 2S in the supplementary material. 155 156 In order to characterise the solid products (i.e. granules and powder), a series of sieves 157 with different mesh sizes were used to separate the solid samples (NCS-G and NCS-P) into 158 different fractions, as described in Table 1. The sieves were operated by mechanical 159 vibration (Retsch AS200, Germany) at amplitude of 70 for 30 min. The weight of samples 160 retained on each sieve was recorded and expressed as fraction (%) of the original sample. 161 162 2.2. Chemicals 163 164 15 Toscano, Santana, & Insuasty, 2007; Velásquez, Espitia, Escobar & Mendieta, 2019). As 306 the concentration process is carried out in direct contact with air, oxidation products are 307 formed because of the long processing time and the high operating temperatures. Also, a 308 variety of volatile compounds present in the original sugarcane juice, or those formed 309 during reactions, can be steam distilled during the boiling operation. Finally, Maillard 310 products are formed by reaction of reducing sugars with primary amines present in the juice 311 or those coming from the mucilaginous material used for clarification. The final molded 312 product is wrapped and sealed with a thermoplastic film, and packed in cardboard boxes for 313 storage and distribution (Velásquez, Espitia, Mendieta, Escobar, & Rodríguez, 2019). 314 315 In comparison, when the product is granulated NCS (corresponding to NCS-G samples), 316 the syrups are boiled for longer times up to a higher solids content (i.e. > 95 °Brix), which 317 correspond to a higher bubble temperature (> 125 °C). The operation under these 318 conditions accelerates different chemical reactions. In general, a larger fraction of the 319 reducing sugars (i.e. glucose and fructose) can react to produce different side products 320 affecting the final sugars profile. Therefore, to reduce hydrolysis of sucrose to reducing 321 sugars, the operation is conducted under higher pH levels (> 6). In this case, a higher 322 amount of calcium hydroxide or calcium carbonate is added with respect to that used in 323 bricks manufacturing (Velásquez, Espitia, Mendieta, Escobar, & Rodríguez, 2019). After 324 the final hot syrup is removed from the last pan, it is subjected to aeration, cooling, manual 325 grinding and sieving. Large particles are subjected to mill grinding and sieving until 326 fulfilling the required particle size specifications. Typically, during the granulation steps 327 the particles can uptake some moisture from the environment, and a final drying could be 328 required. This last step is carried out in heated and agitated drums, or in convective tray 329 16 ovens. Finally, the product is packed in sacks or plastic bags of different sizes (García, 330 Albarracin, Toscano, Santana, & Insuasty, 2007). 331 332 The other assessed product, spray dried powder (NCS-P), was obtained from 333 intermediate syrups of 50 to 70 °Brix collected in the open evaporation process process 334 intended for granulation (i.e. pH > 6). The corresponding bubble temperatures of these 335 syrups are below 105 °C. During the spray drying, the liquid is fed at low temperature, and 336 it is put in contact with air at 140 °C at the atomizer inlet nozzle. The residence time in this 337 unit is very short (< 2 min), and the air rapidly cools down (~ 70-80 °C) because of water 338 evaporation (Palacios, Orjuela, Narváez, & Osorio, 2016). As expected and described in 339 Table 1, particle sizes of the spray dried powders are smaller than those obtained in the 340 granulation process. While 70% of granulated products corresponds to particles larger than 341 0.5 mm, in the case of spray dried products nearly 58 to 64 % corresponded to particles 342 smaller than 0.6 mm. In particular, it was observed that powders obtained from syrups with 343 a lower solid content (P50) exhibited a larger fraction (> 40%) of particles with sizes below 344 0.3 mm. The higher content of fines was related with the more effective atomization in the 345 nozzle when operating with a lower viscosity liquid that enabled the formation of smaller 346 droplets. The proportion of larger particles (> 0.6 mm) after spray drying of assessed syrups 347 was similar (i.e. 36 - 42 %), and it might be related with the aggregation of the particles 348 during the drying process or in the collecting cyclone. Because of the light scattering 349 effect, the spray dried particles have a clearer visual aspect than those in the granulated 350 product, and both have a lighter apparent color to that of the syrups and bricks. 351 352 3.1. Physicochemical characterisation 353 17 3.1.1. Moisture in samples 354 According to the measurements, the moisture content (wet basis) of the bricks (NCS-355 B) was 6.5 % (only one measurement), the granulated product (NCS-G) was 2.74 ± 0.11 % 356 wt., and the spray dried solids, i.e. NCS-P50 and NCS-P70, were 2.31 ± 0.03 % wt. and 357 1.69 ± 0.06 % wt., respectively. These values are consistent with required specifications for 358 brick and granulated NCS (ICONTEC, 2009). 359 360 3.1.2. Sugars profile 361 The sugars profile in the assessed NCS samples are reported in Table 2. As expected, 362 sucrose was the predominant sugar in all samples with a content greater than 91.9% (dry 363 basis). Glucose and fructose, exhibited a lower content corresponding to >2.9% and >1.6%, 364 respectively. This sugar profile is consistent with NCS standards (ICONTEC, 2009) and 365 agrees with those reported in previous studies on the characterisation of NCS samples 366 (Guerra & Mujica, 2010; Segui et al., 2015). The content of reducing sugars can help 367 differentiating NCS from brown sugar, which is a similar natural sweetener obtained by 368 crystallization of concentrated sugarcane molasses, and that has a much lower content of 369 fructose (0.75%), and glucose (0.46%) (Asikin et al., 2014). 370 371 Regarding the processing influence on the sugars profile on the different types of 372 NCS, there were slight differences between NCS-G and NCS-P products in comparison to 373 the brick (NCS-B). Particularly there is a lower content of sucrose in the NCS-B sample, 374 and a higher concentration of reducing sugars. This was expected as the higher pH used in 375 the processing of syrups for granulated products helps inhibiting hydrolysis. Interestingly, 376 there are no differences among syrups obtained at intermediate stages of the evaporation 377 18 process (i.e. S50 and S70). This agrees with a previous report (Alarcón, Orjuela, Narváez, 378 & Camacho, 2020) and indicates that, during most part of the evaporation process, the 379 chemical integrity of saccharides in the syrups is maintained, and that only the solids 380 content changes due to water removal. The lower viscosity and the dissolving action of the 381 boiling syrups below 70 °Brix prevent solids from sticking and caramelising on the pan’s 382 hot surface. 383 384 In average, when comparing the total reducing sugars content in NCS-G, NCS-P50 and 385 NCS-P70 samples, there is a slightly higher content in the granulated product. This is 386 related with a higher degree of hydrolysis as a results of long residence times (i.e. typically 387 10-20 min more compared to the syrup point for brick product) and higher temperatures 388 during NCS-G production. Interestingly, the sugars profile is almost invariant when 389 comparing the spray dried powders and their corresponding syrups of origin (S50 and S70), 390 indicating that the drying conditions do not affect the sugars profile. As the reducing sugars 391 content in the syrups and spray dried products is lower with respect to bricks, this can 392 represent a commercial and operational advantage. A high content of glucose and fructose 393 in NCS is related with a higher hygroscopicity of the product, which affects the texture, and 394 reduces its stability and shelf life (Guerra & Mujica, 2010; Verma, Shah, & Mahajani, 395 2019). Nonetheless, while the reduced hygroscopicity of powdered and granulated material 396 could affect their dissolving rates, the smaller particles sized can help overcoming such 397 difficulties. 398 399 According to a generalized claim among some granulated NCS producers, the 400 difference in particle sizes during granulation is driven by the uneven cluster crystallization 401 19 around local high concentrations of sucrose. Thus, they expect to have larger concentrations 402 of sucrose in the larger particles during granulated NCS production. As observed in Table 403 2, the sugar profile is almost the same among the different fractions of NCS with different 404 particle sizes. This was expected as the mother syrup before the granulation or the spray 405 drying processes is homogeneous, and the solidification process is fast enough to avoid any 406 internal segregation within the solid phase. The claimed behaviour is also disproved when 407 verifying that the content of phenolic and flavonoid compounds among particles of 408 different sizes is almost the same. 409 410 3.1.3. Phenolic and flavonoid compounds 411 Regarding the total phenolic content in the samples (Table 2), it was found that syrups 412 and granulated NCS samples exhibited the highest phenolic contents (>5.6 mg GAE/ g for 413 syrups, and >5.1 mg GAE/ g for NCS-G). Comparatively, the content in spray dried 414 product was around 20% lower. This result agrees with those published by Gómez-Narváez 415 et al. (2019), who compared NCS samples from Colombia, Peru, Italy, and Spain. Also, it 416 is in concordance with the results obtained from different sugarcane sweeteners from 417 Pakistan (Iqbal et al., 2017). In addition, total phenolic content (TPC) calculated in wet 418 base extracts varies over the range of 2.4 and 5.2 mg GAE/g of product. These values are 419 slightly higher than those reported for NCS samples from Spain (1.0 – 2.6 mg GAE/g 420 product, Segui et al., 2015) and India (3.8 mg GAE/g of product, Harish Nayaka et al. 421 2009). The observed differences are attributed to the cane variety and the agro-climatic 422 conditions during the sugar cane crop. The reduction of the phenolic content of the samples 423 NCS-P50 and NCS-P70 with respect to the original syrups is related with losses during the 424 drying process (Rothwell et al., 2015), which are most probably caused by air dragging and 425 20 oxidation at the drying chamber conditions. This indicates that the spray drying process 426 might have an impact on the nutritional value of the powdered NCS. 427 428 The total flavonoid content of NCS samples and syrups was also determined (Table 2). 429 The NCS-B sample presented the lowest value, but still being in the same order of 430 magnitude of the other samples. The observed differences are most probably related to the 431 variety of sugarcane as it was different from the other NCS samples. The higher content of 432 phenolic and flavonoids in NCS-G samples can be explained by the long exposure time at 433 high temperatures during this process. Several phenolic compounds have been reported in 434 NCS samples and syrups, such as, chlorogenic acid, ferulic acid, gallic acid, gentisic acid, 435 p-coumaric acid, p-hydroxy benzoic acid, protocatehuic acid, syringic acid, vanillic acid, 436 and coniferyl alcohol, among others. Additionally, flavonoids such as, apigenin, luteolin 437 and tricin, have also been found in NCS samples (Duarte-Almeida et al., 2011; Harish 438 Nayaka et al., 2009; Jaffé, 2015; Singh et al., 2015). 439 440 It is known that phenolic compounds and flavonoids are highly unstable during NCS 441 processing (Jaffé, 2015). Thermal decomposition or thermal reactions of those compounds 442 can produce new chemical species (Segui et al., 2015) or generate an increase in the 443 phenolic content (Payet et al., 2006). Thus, in a further stage, six phenolic acids were 444 quantified (Table 3) in all NCS samples and syrups, being the most abundant chlorogenic 445 acid and syringic acid, followed by p-coumaric acid, vanillic acid, ferulic acid, and 446 protocatechuic acids. The effect of thermal treatment during processing is more significant 447 for protocatechuic acid, vanillic acid, chlorogenic acid, and ferulic acid, after the 448 comparison of their amount in the S-50, S-70, NCS-G, NCS-P50 and NCS-P70 samples. 449 21 Interestingly, syringic acid amount is higher in NCS-G and in NCS-B samples than in the 450 S-50 and S-70, likely because heating promotes the oxidative breaking of cinnamic acids 451 present in sugar cane syrups (chlorogenic acid, ferulic acid, and p-coumaric acid) (Duarte-452 Almeida et al., 2011). This can also explain the slight differences between S50 and S70, 453 considering that the latter is a syrup that has been subjected to higher temperature for 454 longer times. 455 456 The NCS-G, and NCS-P50 and NCS-P70 samples had a slight reduction in the 457 phenolic acids content in comparison with those of the syrups, with the exception of 458 syringic acid that can be produced from cinnamic acids structurally related such as, ferulic 459 acid or sinapic acid. The granulated material also exhibited a slightly higher content of 460 phenolic acids than the spray dried product. Considering this and taking into account that 461 the spray dried powder is obtained directly from the intermediate syrups that had a higher 462 content of phenolic compounds, it is verified that the drying process can affect the content 463 of phenolic acids. Despite the low residence time, this can be related to oxidation due to the 464 high air temperatures (140 °C), or volatilization of some of the components during the 465 spray drying process promoted by a process occurring in the small drops and not in a liquid 466 bulk. 467 468 The processing influence on the nature and content of phenolic compounds can vary 469 because some of them (e.g. chlorogenic acid) are substrates in enzymatic browning 470 reactions (Payet et al., 2006), while other are more stable. These processes can occur not 471 only during the open evaporation of the juices, but also in the granulation operations (either 472 22 in the milling or in the manual shaking method), and even in the spray drying (depending 473 on the temperature conditions and residence time). 474 475 3.2. Colour measurement 476 477 The average of CIELAB colour space parameters of aqueous solutions of NCS samples 478 obtained in the different processes are presented in Figure 1. NCS-G solutions have the 479 lowest values of lightness among samples. Relating to b* parameter, all values were 480 positive. These values proportionally increased from the lowest to highest thermal NCS 481 treatment (from syrups and powdered to block and granulated NCS samples). Furthermore, 482 the data obtained for NCS-G and NCS-B samples are located in the first a*, b* quadrant, 483 while NCS-S and NCS-P samples were spread out between both, first and second a*, b* 484 quadrant, because of the variation of a* value. 485 486 NCS colour is a quality feature that influences consumers in their purchase decision. 487 They usually prefer light colours, but this property depends on many variables, such as, 488 phenolic content, sugar cane variety and maturity, agroecological conditions, and 489 processing conditions (heating type, temperature, and use of bleach agents, García et al., 490 2017). While the commercial NCS has colours between gold yellow and dark brown 491 (Shrivastav et al., 2016), it is expected that the granulated and powdered products might 492 have clearer colours due to light scattering. Nevertheless, after preparing hot beverages of 493 the same solids concentration (~ 20 % wt. in boiling water) in a similar way to a previous 494 work (García et al., 2017), the perceived colour was similar among all the different 495 solutions. This is a valuable finding because it indicates that the novel spray dried product 496 23 can be used as ingredient in food and beverages applications, and it most certainly would 497 exhibit similar organoleptic behaviour (i.e. colour) than that of the traditional bricks and 498 granules. This was expected considering that generally, spray drying has minor impact on 499 colour-imparting compounds. It has been reported that low molecular weight phenolic 500 compounds extracted from the canes during the milling process are responsible for ~ 30% 501 of colour; while some chemicals produced during the open evaporation process through 502 degradation reactions (i.e. enzymatic and non-enzymatic) contribute to 70% of final colour 503 (Schlumbach, Pautov & Flöter, 2017). The oxidation of phenolic compounds to dark 504 polymers are enzymatic reactions, and caramelisation and Maillard reactions are non-505 enzymatic reactions (Guerra & Mujica, 2010); both of them generate a complex matrix of 506 coloured compounds. 507 508 Statistical relationships between the CIELAB colour coordinates and the phenolic 509 content were made. The complete definition of the colour of any object by means of the 510 CIELAB coordinates requires a joint consideration among the scalar (L*, a*, b*) and the 511 angular (L*, hab and C*ab) values. Hence, a multiple regression study by means of general 512 linear model (GLM) was carried out to get a more meaningful evaluation of the correlation 513 existing between the colour of NCS samples and their phenolic content. For this purpose, 514 the content of each phenolic compounds was considered as dependent variable, and the sets 515 of L*, a*, b* and L*, hab, C*ab coordinates as predictor or independent variables. The 516 corresponding R2 values are listed in Table 4. When the set L*, a*, b* was considered, the 517 highest R2 values were obtained for the contents of vanillic, syringic, protocatechuic, and 518 chlorogenic acids, as well as for total phenolic content. Similarly, when the set L*, hab, C*ab 519 was analyzed, the same phenolic compounds presented the highest R2 values, being the 520 24 protocatechuic acid the one that showed the highest correlation. These results mean that 521 benzoic acids have more influence in the colour of NCS samples that hydroxy cinnamic 522 acids (ferulic and p-coumaric acids). 523 524 Additionally, to determine which variables were the most appropriate for 525 discriminating among samples, Stepwise Discriminant Analysis (SDA) were performed 526 (Figure 2a). L*, glucose and syringic acid content were found statistically significant (p < 527 0.05). Two classification functions were obtained, which yielded a good separation (100% 528 correct classification) among samples. According to data presented in Figure 2b, the 529 discriminant function 1 (root 1) was mainly related to lightness (L*) (with positive sign) 530 and glucose content (negative sign), whereas discriminant function 2 (root 2) was mainly 531 linked to syringic acid content (negative sign). The sets of the points show a distribution 532 pattern in which three well-defined groups can be distinguished. 533 534 Regarding the initial hypothesis, this study enabled to determine that most phenolic 535 compounds and the colour are preserved during spray drying process. However, the use of 536 syrups as raw material for powdered NCS has slight negative impacts in the content of 537 flavonoids. This might represent a challenge in terms of the sensory profile for the spray 538 dried NCS powder as it is intended to be used as substitute for traditional brick or 539 granulated products. Further studies might involve the use of more concentrated syrups or 540 even reconstituted solutions as feed for the spray drying. Also, the slight reduction of 541 phenolic acids in the NCS-P with respect to the original syrups indicates that spray drying 542 conditions must be optimized (e.g. using encapsulating agents, reducing temperatures). 543 544 31 sensory and storage characteristics of muffins. Journal of Food Science and 689 Technology, 55 (8), 3144–3153. https://doi.org/10.1007/s13197-018-3242-7 690 MinAgricultura (2018) Agroindustrial Chain of Panela. (In spanish). URL. 691 https://sioc.minagricultura.gov.co/Panela/Documentos/2018-12-692 30%20Cifras%20Sectoriales.pdf. (Consulted June 2020). Accessed 07.06.20. 693 Mohan, N., & Agarwal, A. (2020) New ventures of value-addition in jaggery processing for 694 a dynamic sugar industry. International Journal of Engineering Research & 695 Technology 9 (1), 291-294. https://www.ijert.org/research/new-ventures-of-value-696 addition-in-jaggery-processing-for-a-dynamic-sugar-industry-IJERTV9IS010179.pdf 697 Palacios, L. M., Orjuela A., Narváez, P. C. & Osorio, C. (2016). Spray drying of sugarcane 698 honeys (Saccharum officinarum L.) without additives. Agronomía Colombiana, 34 (1 699 Supl.), S649-S651. https://doi.org/10.15446/agron.colomb.v34n1supl.58429 700 Payet, B., Sing, A. S. C. & Smadja, J. (2006). Comparison of the concentrations of phenolic 701 constituents in cane sugar manufacturing products with their antioxidant activities. J. 702 Agric. Food Chem. 54 (19), 7270-7276. https://doi.org/10.1021/jf060808o 703 Prada-Forero, L. E., García-Bernal H. R. & Chaves-Guerrero, A. (2015). Effect of 704 evaporation varables: pressure and heat flow in the quality of panela. (In spanish) 705 Corpoica Ciencia y Tecnología Agropecuaria, 16 (1), 7-23. 706 https://doi.org/10.21930/rcta.vol16_num1_art:376 707 Rothwell, J. A., Medina‐Remón, A., Pérez‐Jiménez, J., Neveu, V., Knaze, V., Slimani, N., 708 Scalbert, A. (2015). Effects of food processing on polyphenol contents: A systematic 709 analysis using phenol-explorer data. Molecular Nutrition & Food Research, 59 (1), 710 160-170. https://doi.org/10.1002/mnfr.20140049 711 Schlumbach, K., Pautov, A. & Flöter, E. (2017). Crystallization and analysis of beet and 712 32 cane sugar blends. Journal of Food Engineering, 196 (1), 159-169. 713 https://doi.org/10.1016/j.jfoodeng.2016.10.026 714 Seguí, L., Calabuig-Jiménez, L., Betoret, N. & Fito, P. (2015). Physicochemical and 715 antioxidant properties of non-refined sugarcane alternatives to white sugar. 716 International Journal of Food Science Technology, 50 (12), 2579-2588. 717 https://doi.org/10.1111/ijfs.12926 718 Shrivastav, P., Verma, A.K., Walia, R. & Parveen, R. (2016). Jaggery : a revolution in the 719 field of natural sweeteners. European Journal Pharmaceutical and Medical Research, 720 3 (3), 198-202. 721 Singh, A., Lal, U., Mukhtar, H., Singh, P., Shah, G. & Dhawan, R. (2016). Phytochemical 722 profile of sugarcane and its potential health aspects. Pharmacognosy Reviews, 9 (17), 723 45-54. https://doi.org/10.4103/0973-7847.156340 724 Solís, J. A., Hernández, Y., Hernández, M., García, R. S., Bernal, M., Mendoza, S., & 725 Durán, M. (2019) Quality improvement of jaggery, a traditional sweetener, using 726 bagasse activated carbon. Food Bioscience 32 (1), 100444. 727 https://doi.org/10.1016/j.fbio.2019.100444 728 Truong, V., Bhandari, B. R. & Howes, T. (2005). Optimization of co-current spray drying 729 process of sugar-rich foods. Part I—Moisture and glass transition temperature profile 730 during drying. Journal of Food Engineering, 71 (1), 55-65. 731 https://doi.org/10.1016/j.jfoodeng.2004.10.017 732 Velásquez, F., Espitia, J., Mendieta, O., Escobar, S., Rodríguez, J. (2019) Non-centrifugal 733 cane sugar processing: A review on recent advances and the influence of process 734 variables on qualities attributes of final products. Journal of Food Engineering 255 735 (1), 32–40. https://doi.org/10.1016/j.jfoodeng.2019.03.009 736 33 Vera, T., García, M. C., Otalvaro, A. M., & Mendieta, O. (2019) Effect of processing 737 technology and sugarcane varieties on the quality properties of unrefined non-738 centrifugal sugar. Heliyon 5 (10) e02667. 739 https://doi.org/10.1016/j.heliyon.2019.e02667 740 Verma, P., Shah, N. G., & Mahajani, S. M. (2019) Why jaggery powder is more stable than 741 solid jaggery blocks. LWT - Food Science and Technology 110, 299–306. 742 https://doi.org/10.1016/j.lwt.2019.04.093 743 Verma, P., Iyer, S. R., Shah, N., & Mahajani, S. M. (2021) Insights into the crystallization 744 phenomenon in the production of non-centrifugal sugar. Journal of Food Engineering 745 290, 110259. https://doi.org/10.1016/j.jfoodeng.2020.110259 746 747 34 Figure captions 748 749 Fig. 1. Projection of the colour points corresponding to each sample on the (a* b*) diagram 750 of colour parameters. NCS-G (○), NCS-P (□), NCS-S (●), NCS-B (∆). 751 Fig. 2. Stepwise Discriminant Analysis (SDA). Loading plot for colour parameters, 752 phenolic, and sugar content measured in NCS samples (NCS-G (○), NCS-P (□), NCS-S 753 (●), and discriminant power (F-value) of the variables selected and cooeficients of 754 discriminant functions 755 756 757 758 759 760 761 762 763 764 765 766 35 Figure 1. 767 768 769 36 Figure 2. 770 771 772 773 774 775 776 777 778 779 780 781 782 Variable F-value Standardized coefficients Root 1 Root 2 L* 86.447 7.801 0.650 Glucose 18.431 -6.409 1.696 Syringic acid 12.035 2.312 -2.663 Eigenval 1650.912 82.637 Cum.Prop 0.952 1.000 783 784 785 Root 1 Root 2 -60 -40 -20 0 20 40 60 80 -15 -10 -5 0 5 10 Root 1 Root 2 10 5 0 -10 -5 -15 20 0 -20 40 -40 60 80 -60 37 Table 1 786 Description of NCS samples obtained by different processes 787 Sample Nomenclature Mesh size (mm) Fraction % NCS-G (granulated) G1 > 1 23.64 G2 0.8 4.95 G3 0.6 5.92 G4 0.5 35.60 G5 <0.5 29.89 NCS - P50 (Powdered from 50 °Brix syrups) P50-1 > 0.6 36.14 P50-2 0.4 9.46 P50-3 0.3 12.20 P50-4 < 0.3 42.20 NCS - P70 (Powdered from 70°Brix syrups) P70-1 > 0.6 41.99 P70-2 0.4 26.89 P70-3 0.3 23.43 P70-4 < 0.3 7.69 NCS - B (Block) B NA NA NCS - S50 (50 °Brix syrup, AOAC 932.12) S50 NA NA NCS - S70 (70 °Brix syrup, AOAC 932.12) S70 NA NA NA. Not applicable 788 789 790 791 792 38 Table 2 793 Sugar, total phenol and flavonoid-contents (dry basis) in NCS samples obtained by 794 different processing 795 Sample Sucrose (g / 100g product) Glucose (g / 100g product) Fructose (g / 100g product) Total phenolic content (mg GAE/g product) Total flavonoid content (mg CE/g product) NCS-G1 92.9 ± 2.9a 4.6 ± 0.2a 3.7 ± 0.2a 5.8 ± 0.1a 2.8 ± 0.1a NCS-G2 93.0 ± 2.9a 4.3 ± 0.2a 2.7 ± 0.1b 5.9 ± 0.2a 3.0 ± 0.3a NCS-G3 93.1 ± 2.2a 4.2 ± 0.0a 2.7 ± 0.2b 5.9 ± 0.2a 3.0 ± 0.1a NCS-G4 94.1 ± 1.5a 3.6 ± 0.2b 2.4 ± 0.0c 5.4 ± 0.2b 2.9 ± 0.1a NCS-G5 94.2 ± 2.9a 3.6 ± 0.2b 2.2 ± 0.1d 5.1 ± 0.2b,e,g 3.8 ± 0.1b NCS-P50-1 94.5 ± 2.2a 3.4 ± 0.3b,c 2.1 ± 0.2d,e 4.0 ± 0.2c 2.5 ± 0.2a,c NCS-P50-2 94.6 ± 5.0a 3.5 ± 0.1b 1.9 ± 0.1e 4.4 ± 0.1d 2.7 ± 0.2a,c NCS-P50-3 94.6 ± 1.0a,b 3.4 ± 0.1b,c 2.0 ± 0.1d 4.6 ± 0.1d 2.9 ± 0.1a NCS-P50-4 95.5 ± 1.4a,c 2.9 ± 0.4c 1.6 ± 0.1f 4.5 ± 0.2d 3.2 ± 0.2d NCS-P70-1 94.6 ± 4.3a 3.5 ± 0.4b,c 1.9 ± 0.2d,e,f 4.9 ± 0.1e 3.3 ± 0.1d NCS-P70-2 94.9 ± 2.9a 3.4 ± 0.6b,c 1.8 ± 0.3d,e,f 4.7 ± 0.1f 2.6 ± 0.2a NCS-P70-3 94.6 ± 3.2a 3.3 ± 0.7b,c 2.1 ± 0.2d,e 4.6 ± 0.0f 2.3 ± 0.2c,e NCS-P70-4 95.0 ± 5.0a 2.9 ± 0.9b,c 2.1 ± 0.1d,e 4.7 ± 0.2g 2.4 ± 0.1c NCS-B 91.9 ± 1.5a,b,c 4.4 ± 0.2a 3.7 ± 0.1a 4.3 ± 0.1c 2.0 ± 0.2e NCS-S50 94.4 ± 4.8a 3.5 ± 0.5b,c 2.1 ± 0.2d,e 5.7 ± 0.1a,b 3.2 ± 0.1d NCS-S70 94.9 ± 1.8a 3.2 ± 0.2b,c 1.9 ± 0.2d,e 5.6 ± 0.3a,b 2.7 ± 0.1a,c NCS-G: granulated NCS; NCS-P: powdered NCS at different mesh from 50 °Brix (P50) 796 and 70 °Brix (P70); NCS-B: NCS block sample; NCS-S50: syrup 50 °Brix, and NCS-S70: 797 70 °Brix. GAE = gallic acid equivalent; CE = catechin equivalent. a–g Means within a 798 column, values with different superscript letters differ significantly (p < 0.05). 799 800 801 39 Table 3 802 Quantitation of phenolic compounds in NCS samples obtained by different processing 803 methods 804 NCS-G: granulated NCS; NCS-P: powdered NCS at different mesh from 50 °Brix (P50) 805 and 70 °Brix (P70); NCS-B: NCS block sample; NCS-S50: syrup 50 °Brix, and NCS-S70: 806 70 °Brix. a–g Means within a column, values with different superscript letters differ 807 significantly (p < 0.05). 808 809 810 Sample Protocatechuic acid Vanillic acid Chlorogenic acid Syringic acid p-Coumaric acid Ferulic acid µg phenolic compound/g of product (dry basis) NCS-G1 0.54 ± 0.05a,b 0.97 ± 0.09a,b,e 2.68 ± 0.12a 2.56 ± 0.04a 1.31 ± 0.03a 0.81 ± 0.01a NCS-G2 0.54 ± 0.03a 0.97 ± 0.08a,b,e 2.62 ± 0.12a 2.61 ± 0.05ª 1.30 ± 0.03a 0.95 ± 0.10b NCS-G3 0.49 ± 0.03a,b,c 0.93 ± 0.02a,b,e 2.80 ± 0.06a 2.57 ± 0.04a 1.35 ± 0.01a 0.76 ± 0.10b NCS-G4 0.45 ± 0.05a,b 0.80 ± 0.01b 2.48 ± 0.07b 2.27 ± 0.10b 0.71 ± 0.04b 0.50 ± 0.04c NCS-G5 0.49 ± 0.02b 0.86 ± 0.03a 2.48 ± 0.10a,b 2.35 ± 0.10b 0.69 ± 0.05b 0.66 ± 0.07d NCS-P50-1 0.39 ± 0.03b,c 0.85 ± 0.04a 3.09 ± 0.12c 1.76 ± 0.03c 0.99 ± 0.05c 0.94 ± 0.08b NCS-P50-2 0.36 ± 0.01c 0.83 ± 0.02b 3.09 ± 0.14c 1.73 ± 0.07c 0.94 ± 0.05c 0.86 ± 0.04b NCS-P50-3 0.41 ± 0.06b,c 0.82 ± 0.04b 2.94 ± 0.07c 1.77 ± 0.04c 0.90 ± 0.06c 0.80 ± 0.06b NCS-P50-4 0.38 ± 0.10ª,b,c 0.83 ± 0.03b 2.85 ± 0.08c 1.77 ± 0.07c 1.07 ± 0.03d 0.91± 0.10b NCS-P70-1 0.46 ± 0.08ª,b,c 0.77 ± 0.03b 2.57 ± 0.07d 1.58 ± 0.05d 1.01 ± 0.04c 0.79 ± 0.09b NCS-P70-2 0.43 ± 0.15ª,b,c 0.80 ± 0.09b 2.52 ± 0.04d 1.58 ± 0.02d 0.99 ± 0.04c 0.73 ± 0.08d NCS-P70-3 0.42 ± 0.12ª,b,c 0.81 ± 0.03b 2.66 ± 0.27a 1.60 ± 0.05d 1.01 ± 0.07c 0.77 ± 0.09d NCS-P70-4 0.43 ± 0.01b 0.71 ± 0.04c 2.62 ± 0.08d 1.09 ± 0.05e 0.95 ± 0.02c 0.89 ± 0.07c NCS-B 0.49 ± 0.02b 0.89 ± 0.03b 2.08 ± 0.11e 2.81± 0.04f 0.93 ± 0.05c 0.60 ± 0.00d NCS-S50 0.95 ± 0.19d 1.45 ± 0.07d 3.82 ± 0.05f 1.43 ± 0.10 g 1.03 ± 0.04c 0.93 ± 0.00c NCS-S70 0.79 ± 0.18d 1.09 ± 0.06e 2.83 ± 0.03g 1.79 ± 0.03c 1.01 ± 0.04c 1.51 ± 0.07e 40 Table 4 811 Coefficient of determination from the multiple regressions between the content of phenolic 812 compounds and the corresponding Lab parameters (scalar and angular coordinates*) a 813 814 815 816 817 818 819 820 821 822 a Significant effect (p < 0.05). 823 L*, a*, b* L*, hab, Cab* Total phenolic content 0.6768a 0.7813a Total flavonoid content 0.2430 0.2371 Protocatechuic acid 0.7685a 0.8058a Vanillic acid 0.8190a 0.7896a Chlorogenic acid 0.7423a 0.7886a Syringic acid 0.7916a 0.7649a p-Coumaric acid 0.0423 0.0544 Ferulic acid 0.3044 0.3335