Antioxidant capacity, fatty acids profile, and descriptive sensory analysis of table olives as affected by deficit irrigation

1 An t iox idan t capacit y , fat t y acids pr ofile, an d d escr ip t iv e 1 sen sor y an aly sis of t able oliv es as aff ect ed by d ef icit ir r ig at ion 2 3 Cano-Lamadrid M.* a , Hernández F. b , Corell M. c,d , Burló F. a , Legua P. b , Moriana A. c,d , 4 Carbonell-Barrachina A.A. a 5 6 a Universidad Miguel Hernández de Elche (UMH), Escuela Politécnica Superior de 7 Orihuela, Departm ent of Agro-Food Technology, Research Group “Food Quality and 8 Safety”, Ctra. Beniel, km 3.2, 03312-Orihuela, Alicante, Spain 9 b Universidad Miguel Hernández de Elche (UMH), Escuela Politécnica Superior de 10 Orihuela, Department of Plant Sciences and Microbiology, Research Group “Plant 11 Production and Technology”, Ctra. de Beniel, km 3,2. 03312-Orihuela, Alicante, 12 Spain 13 c Unidad Asociada al CSIC de Uso Sostenible del Suelo y el Agua en la Agricultura 14 (US-I RNAS), Ctra. de Utrera, km 1, 41013, Sevilla, Spain 15 d Universidad de Sevilla, Departam ento de Ciencias Agroforestales, ETSIA, Ctra. de 16 Utrera, km 1, 41013-Sevilla, Spain 17 18 19 20 21 Ru n n in g t it le: Functional properties of hydroSOStainable table olives 22 23 24 25 * Corresponding author: m arina.cano.um h@gm ail.com 26 27 P r e p r i n t s u b m i t t e d t o : J o h n W i l e y & S o n s 2 Ab b r ev iat io n s 28 AA: antioxidant activity 29 AW: applied water 30 dw: dry weight 31 ETc: crop evapotranspiration 32 FAMEs: fatty acids m ethyl esters 33 fw: fresh weight 34 GAE: gallic acid equivalents 35 H-AA: hidrofilic antioxidant activity 36 L-AA: lipophilic antioxidant activity 37 MUFA: monounsaturated fatty acids 38 PUFA: polyunsaturated fatty acids 39 RDI : regulated deficit irrigation 40 RID: refractive index detector 41 TGR: trunk growth rate 42 TPC: total polyphenols content 43 3 ABSTRACT 44 45 The influence of 3 irrigation treatments (T0, no stress; T1, soft stress; and, 46 T2, m oderate stress) on the key functional properties [ fatty acids, sugars, organic 47 acids, minerals, total polyphenols content (TPC), and antioxidant activity (AA)] , 48 sensory quality, and consum ers’ acceptance of table olives, cv. “ Manzanilla”, was 49 evaluated. A soft water stress, T1, led to table olives with the highest oil and dry 50 matter contents, with the highest intensities of key sensory attributes and slightly, 51 although not significant, higher values of consum er satisfaction degree. Besides, 52 RDI in general (T1 and T2) slightly increased green color, the content of linoleic 53 acid, but decreased the content of phytic acid and some m inerals. The final 54 conclusion is that soft RDI conditions are a good option for the cultivation of olive 55 trees because they are environm ental-friendly and simultaneously maintains or 56 even improves the functionality, sensory quality, and consum er acceptance of table 57 olives. 58 59 Key w or ds: consum ers; functional; hydrosostainable; Olea europaea L.; water 60 stress; “ Manzanilla”. 61 62 4 1. I NTRODUCTI ON 63 64 Olive (Olea europaea L.) is the m ost extensive tree crop of the Mediterranean 65 basin and has been traditionally cultivated in marginal areas with low density under 66 rainfall conditions (I niesta, Testi, Orgaz, & Villalobos, 2009). The aridity of the 67 climate and the persistent shortage of water resources in the Mediterranean 68 agrosystem s are aggravated by strong competition for the available water with 69 other nonagricultural users, for exam ple intense use in touristic areas during 70 sum m er tim e (Collado-González et al., 2015a). These problem s have led to 71 developm ent of new water saving techniques, such as regulated deficit irrigation 72 (RDI ). This technique in olive trees (drought tolerant plant) is m ainly based on 73 scheduling a water deficit period during pit hardening; it has been proved that this 74 stage is a non-critical phenological period (Goldham er, 1999). I n this way, it is 75 possible to save water in the irrigation of olive trees but with a m inim um im pact on 76 yield and fruit quality (Janick & Naor, 2006). 77 Table olives are prepared from the fruit of the olive tree because fresh olives 78 are not edible (Boskou, Cam poseo, & Clodoveo, 2015). Table olives are probably 79 the most im portant ferm ented food in the Mediterranean countries and are very 80 valuable because of their highly appreciated taste and rich nutritional com position 81 leading to interesting health benefits (Aktas, Ozen, Tokatli, & Sen, 2014). 82 Therefore, the daily consum ption of table olives will contribute in an im portant way 83 to the intake of healthy substances, such as phenolic com pounds, which are highly 84 recom m ended because their antioxidant properties (Fabiani et al., 2011). 85 Although irrigation norm ally has positive impact on olive production, it is also 86 known that different water regimes can affect its nutritional, antioxidant and quality 87 com ponents (Servili et al., 2007; Góm ez-Rico et al., 2007). Cano-Lamadrid, Girón, 88 Pleite, Burló, Corell, Moriana & Carbonell-Barrachina (2015) concluded that RDI can 89 affect the quality of Manzanilla table olives, including fruit size, color, texture, 90 volatile and fatty acids profiles, and even consum er satisfaction. Sim ultaneously, 91 5 Collado-González et al. (2015b) using raw olives, from the same RDI treatm ents, 92 showed the effects of RDI on some functional components, phytoprostanes. I n 93 these two studies, the RDI was applied during the pit hardening period. However, 94 there are no studies about the effects of RDI on antioxidant activity, mineral 95 com position, or sugars and organic acids profiles. 96 Table olives cultivated under RDI conditions are considered as 97 “hydroSOStainable” products, and have a solid identity (higher contents of essential 98 com ponents, higher intensity of key sensory attributes, etc.); besides, they can be 99 a good alternative for this type of crop and reduce the econom ic and environm ental 100 costs linked to irrigation, optim izing the use of a very valuable resource in the 101 word, water (Cano-Lamadrid, et al., 2015). 102 Considering all the above, the m ain aim of this work was to evaluate the 103 effects of RDI conditions on key functional properties of Manzanilla table olives. The 104 functionality of table olives was studied by evaluating their (i) nutritional 105 com position: fatty acids, sugars, organic acids, and minerals profiles, and (ii) 106 antioxidant properties: DPPH, FRAP, ABTS, and total polyphenols content. These 107 analyses were completed by evaluating the effects of RDI on (i) morphology: yield 108 per tree, weight, and size, and CIEL* a* b* color, and (ii) sensory quality: 109 descriptive profile using a trained panel, and consum er acceptance using an 110 affective panel. 111 6 2 . MATERI ALS AND METHODS 112 113 2 .1 . Plan t Mat er ial, Gr ow in g Con d it io n s an d Ex p er im en t al Desig n 114 Fresh green olives were produced at the experim ental farm "The Ham pa" 115 located in Coria del Río (Seville, Spain); this farm is property of the Spanish Higher 116 Council for Scientific Research (CSIC). The plot has an area of 0.5 ha and consists 117 of olive trees (44 years of age) of the variety “Manzanilla de Sevilla”. 118 Depending on the phenological stages of the trees and the water stress 119 established in each of these stages, two types of RDI were applied together with a 120 control treatm ent. The water stress levels in the RDI treatments were controlled 121 using indicators of trunk diam eter fluctuations (Moriana, Corell, Girón, Conejero, 122 Morales, Torrecillas, & Moreno, 2013). The specific indicator selected in this work 123 was the trunk growth rate (TGR, difference between two consecutive m aximum 124 values in the cycles of shrinkage and swelling of the trunks). This indicator was 125 considered as the m ost accurate one in olive trees (Moriana, & Fereres, 2002), and 126 was selected to characterize the water status of this field experiment. 127 It is import ant to describe the different stages of the developm ent of the olive 128 fruit: (i) stage I : it starts at the beginning of the fruit growth and ends at the 129 beginning of the m assive pit hardening; (ii) stage I I : period in which pit hardens; 130 and finally, (iii) stage I I I : period of oil accum ulation and maturation. The irrigation 131 treatm ents under study were: 132 Control (T0): Irrigation was applied to supply the estimated crop 133 evapotranspiration (ETc); this m eans that a full replenishing of all the 134 extracted soil water was conducted by addition of irrigation water. 135 RDI -1 (T1, soft stress): (i) olive trees were under low water deficit 136 conditions; in this way, trees were only irrigated when the TGR (trunk 137 growth rate) was lower than 10 m day -1 (this is half of the value found in 138 trees under fully irrigated conditions) (ii) sam e conditions as in stage I; 139 7 and, (iii) finally at the stage I II , enough water was applied to reach a water 140 status sim ilar to that of T0 trees. 141 RDI -2 (T2, m oderate stress): (i) during the stage I , olive trees were under 142 low water deficit conditions; trees were only irrigated when the TGR was 143 lower than 10 m day -1 ; (ii) trees were not irrigated during stage II ; and, 144 (iii) finally at the stage I I I , enough water was applied to reach a water 145 status sim ilar to that of T0 trees. 146 A randomized complete-block design was used with 3 blocks per treatm ent 147 and 2 trees per block. I rrigation scheduling was controlled with the m easurements 148 of 6 trees per treatm ent (2 per block) along the growing season. 149 2 .2 . Sam p le Pr ocessin g 150 “Manzanilla” olives from the three RDI treatm ents were hand-harvested in 151 mid-September at their optim al m ature-green stage. All fruits from all the trees of 152 each RDI treatm ent were systematically m ixed and a sample of approxim ately 50 153 kg per treatm ent was used to prepare table olives. Fruits were transported the day 154 after their picking at the farm to the Cooperativa Nuestra Señora de las Virtudes 155 (La Puebla de Cazalla, Seville, Spain) to be processed as table olives according to 156 the Spanish style m ethod; the details of this m ethods can be found in Cano- 157 Lamadrid, et al., (2015). 158 2 .3 . Mo r p h olog ical an d p h y sico - ch em ical an aly sis 159 All physico-chemical analyses were only conducted on ferm ented table olives. 160 Approxim ately 5 kg of table olives per treatm ent were used; this m eans that about 161 1000-1250 fruits per treatm ent were evaluated (4.0-4.5 g per fruit). 162 2 .3 .1 . W eig h t an d size 163 One hundred table olives from each treatment were random ly selected and 164 the weight of the whole fruit was m easured using a scale Mettler Toledo m odel 165 AG204 (Barcelona, Spain). Later, the two dimensions (equatorial and longitudinal 166 diameters) of the olives were m easured using a digital caliper Mitutoyo 500-197-20 167 (Illinois, United States of Am erica). 168 8 2 .3 .2 . I n st r u m en t al color 169 Instrum ental color m easurem ents were m ade using a Minolta Colorimeter CR- 170 300 (Osaka, Japan), at 25 ± 2 ˚ C. This spectrophotometer uses an illum inant D 65 171 and a 10˚ observer as references. Color data are provided as CIEL* a* b* 172 coordinates, which define the color in a three-dim ensional space. Color analyses 173 were run in 3 batches of 25 fruits, m aking a total of 75 fruits per treatm ent. 174 2 .3 .3 . Oil con t en t an d fat t y acids 175 Oil was extracted by sonication using a 1 L ultrasonic Selecta bath m odel 176 3000512 JP (Barcelona, Spain). A 2 g of ground olive flesh was mixed with 3 m L of 177 cyclohexane and the m ixture was sonicated at room tem perature for 3 h. Then, the 178 mixture was centrifuged, and the oil was recovered after the evaporation of the 179 cyclohexane in a nitrogen stream. 180 The fatty acids m ethyl esters (FAMEs) were prepared, identified, and 181 quantified using the m ethod recently described by Cano-Lamadrid, et al., (2015). 182 2 .3 .4 . Min er al an aly sis 183 Approxim ately 1 g of m illed table olive were digested, for 3 h a temperature 184 below 130º C, in a multi-place digestion block, Selecta Block Digest 20 (Barcelona, 185 Spain) after the addition 5 mL of concentrated, 65% (w/ v), HNO 3 (Carbonell- 186 Barrachina, García, Sánchez-Soriano, Aracil, & Burló, 2002). Samples were left to 187 cool down to room temperature, transferred to volum etric flask and dilutions 1: 10 188 and 1: 50 were prepared using ultrapure deionized water, 18 MΩ (Milli-Q ® system , 189 Millipore Corporation, Madrid, Spain). 190 Determination of macro-nutrients (Ca, Mg, and K) and m icro-nutrients (Cu, 191 Fe, Mn, and Zn) in previously mineralized samples was perform ed using a Unicam 192 Solaar 969 atomic absorption-emission spectrometer (Unicam Ltd., Cambridge, 193 U.K.). All minerals were analyzed using atom ic absorption except K that was 194 measured using atom ic em ission. 195 9 In each analytical batch, at least one reagent blank and one spike were 196 included to assess precision and accuracy for chem ical analysis. Calibration curves 197 were used for the quantification of m inerals and showed good linearity (R 2 ≥0.999). 198 Analyses were run in triplicate. 199 2 .3 .5 . Su gar s an d or g an ic acid s 200 Organic acids and sugars were quantified according to Sánchez, Calín- 201 Sánchez, Carbonell-Barrachina, Melgarejo, Hernández, & Martínez (2014). Briefly, 202 for each sample, 2 g of table olives were hom ogenized in 5 m L of 50 m M phosphate 203 buffer pH= 7.8. The mixture was centrifuged at 10000 g for 20 m in at 4º C (Sigm a 204 3–18K, Osterode and Harz, Germ any). Then, 1 m L of supernatant was filtered 205 through a 0.45 µm filter and injected into a Hewlett-Packard HPLC series 1100 206 (Wilm ington Del., U.S.A.). The elution buffer consisted of 0.1% phosphoric acid 207 with a flow rate of 0.5 m L m in -1 . Organic acids were isolated using a Supelco 208 colum n (SupelcogelTM C-610H colum n 30 cm × 7.8 mm ) and Supelguard (5 cm x 209 4.6 mm, Supelco, I nc., Bellefonte, PA) and absorbance was m easured at 210 nm 210 using a diode-array detector (DAD). These sam e HPLC conditions were used for the 211 analysis of sugars; however, the detection was conducted using a refractive index 212 detector (RI D). Standards of organic acids (phytic, ascorbic, citric, m alic, tartaric, 213 quinic, shikimic, lactic, and oxalic acids) and sugars (glucose, fructose, sucrose, 214 sorbitol, m altitol, and glycerol) were obtained from Sigm a (Poole, Dorset, UK). 215 Calibration curves, obtained by triplicate injection of standard solutions, were 216 conducted and showed good linearity (R 2 > 0.999). Results were expressed in g kg -1 217 fw (fresh weight) of table olives. 218 2 .3 .6 . An t io x id an t act iv it y ( ABTS, DPPH an d FRAP m et h ods) an d t ot al 219 poly ph en ols 220 For the antioxidant activity determination, a methanol extract was prepared 221 for each sam ple to be analyzed. Approxim ately 0.5 g of freeze-dried table olives 222 were mixed with 10 mL of MeOH/ water (80: 20, v/ v) + 1 % HCl, and the m ixture 223 was sonicated at 20 º C for 15 m in and left for 24 h at 4 º C. Then, the extract was 224 16 and after an initial increase in the accum ulation of oil and DMC, the contents start 375 to be reduced, as seen in T2 olives. 376 3 .2 .4 . Fat t y acid s 377 The relative abundance of fatty acids observed in table olives followed the 378 order: C18: 1 (m ean of all treatments 73.1% ) > > C16: 0 (17.0% ) > C18: 2 (4.1% ) 379 ≈ C18: 0 (3.6% ) > C16: 1 (1.6% ) > C20: 0 (0.4% ) ≈ C20: 1 (0.2% ) (Tab le 3 ). 380 Linoleic (C18: 2) and oleic (C18: 1) acids were significantly affected by the RDI 381 treatm ents (Tab le 3 ). The m ost im portant result is that severe RDI conditions (T2) 382 significantly increased the content of linoleic acid, an ω-6 fatty acid, which m ust be 383 ingested through food due to the fact that hum an body is not able of produce it and 384 therefore is called "essential fatty acid” (Lunn & Theobald 2006; FAO 2010). As a 385 result of the changes in linoleic and oleic acid, T2 table olives experienced a 386 significant increase of PUFAs (polyunsaturated fatty acids) and a simultaneous 387 decreased of MUFAs (m onounsaturated fatty acids), with this being important 388 because PUFAs are beneficial to hum an health (FAO, 2010). A similar trend, but 389 only valid for moderate stressed Manzanilla de Sevilla olives was recently reported 390 by Cano-Lam adrid et al. (2015). 391 3 .2 .5 . Min er als con t en t 392 Only the content of the m acro-nutrient calcium (Ca) was significantly affected 393 by the RDI treatm ents; with the highest content being found in fruits from the 394 control trees, T0 (Tab le 4 ). The contents of the macro-nutrients followed the 395 order: Ca (m ean of all treatments 2.4 g kg -1 ) > K (1.6 g kg -1 ) > Mg (0.4 g kg -1 ). 396 Water stress caused a lower accumulation of Ca in T1 and T2 fruits, this is in water 397 stressed olives; it is important to mention that Ca is taken up by the plant and 398 transported prim arily through the xylem , along with water (Giliham , Dayod, 399 Hocking, Xu, Conn, Kaiser, Leigh & Tyerm an, 2011). Therefore, the absorption of 400 Ca is directly related to plant transpiration; besides, Ca follows the transpiration 401 stream and consequently for this m ineral is difficult to reach plant organs with low 402 transpiration rate, such as fruits (Giliham , et al., 2011). Sodium (Na) was not 403 17 analyzed because is one of the major ingredients used during the processing of 404 table olives. 405 Table olives are a good source of iron (Fe), with the contents of the studied 406 micro-nutrients following the order: Fe (m ean of all treatm ents 11.8 m g kg -1 ) > Cu 407 (8.0 mg kg -1 ) > Zn (5.0 m g kg -1 ) ≈ Mn (4.5 mg kg -1 ). The irrigation treatm ents 408 affected the contents of two of these m inerals, Zn and Mn; in both cases, the 409 higher the water stress, the lower the minerals contents. 410 3 .2 .6 . Su gar s an d or g an ic acid s 411 Only two sugars (m altitol and glycerol) and two organic acids (phytic and 412 lactic acids) were identified and quantified in “ Manzanilla” table olives (Tab le 5 ). 413 The only significant effect (p< 0.05) of the RDI treatm ents on the contents of sugars 414 and organic acids, was a reduction of the content of phytic acid [ known as inositol 415 hexakisphosphate (I P6)] in T1 and T2 fruits (m ean of 6.8 g kg -1 fw) as com pared to 416 control fruits (14.7 g kg -1 fw). Recent investigations have begun to focus on 417 possible beneficial physiological/ health effects of food phytates, which until few 418 years were m ainly considered as anti-nutrient (Urbano, López-Jurado, Aranda, 419 Vidal-Valverde, Tenorio & Porrs, 2000). The possible beneficial effects of food 420 phytates include lowering of serum cholesterol and triglycerides and protection 421 against certain diseases such as cardiovascular diseases, renal stone form ation, and 422 even certain types of cancers (Thompson, 1993; Zhou & Erdm an, 1995; Graf, 423 1983). The absence of reducing sugars in table olives was expected because they 424 are major substrates of the lactic fermentation (the only typical spontaneous lactic 425 process followed in Spanish-style green olives). 426 3 .2 .7 . An t iox id an t act iv it y an d t o t al p oly p h en ols 427 There are different methods for evaluating the antioxidant activity (AA) of 428 foods. This variety of m ethods is due to the fact that none of them is able to 429 determ ine exactly the total antioxidant capacity of a product. The m easured AA of a 430 sam ple depends on methodology and on free radical generator or oxidant in the 431 measurem ent (Cao, Alessio, & Cutler, 1993). Electron-transfer-based assays 432 18 (ABTS, FRAP, and DPPH) m easure the capacity of an antioxidant in the reduction of 433 an oxidant which changes colour when reduced. However, there are differences 434 among them ; for instance, ABTS m easures both hydrophilic and lipophilic AA, while 435 DPPH only considers lipophilic com pounds (Kuskoski, Asuero, Troncoso, Mancini- 436 Filho, & Fett, 2005). For this reason, the antioxidant activity of “Manzanilla” table 437 olives was evaluated using three different analytical m ethods: ABTS, DPPH, and 438 FRAP (Tab le 6 ). The AA and TPC were not significantly affected (p> 0.05) by the 439 RDI treatments. The total polyphenols content found in table olives (5.28 g GAE kg - 440 1 fw, m ean value for all treatm ents) was higher than that previously reported in the 441 flesh of table olives by Boskou et al. (2006), who reported values ranging from 0.8 442 to 1.7 g caffeic acid kg -1 . These authors also identified oleanolic acid, hydroxyl- 443 tyrosol, and tyrosol as the m ain polyphenols present in Greek table olives. Table 444 olives are highly consum ed by the Mediterranean population. The consum ption of 445 20 g of table olives (approxim ately 5 units) provides about 100 m g of polyphenols. 446 Taking into account these results, it can be concluded that Spanish table olives are 447 a very good source of polyphenols and can help in the prevention of m any health 448 diseases. 449 3 .3 . Sen so r y An aly sis 450 The satisfaction degree of 100 Spanish consumers on “Manzanilla” table olives 451 was not affected at all by the RDI treatments (Table 7 ); neither the global 452 satisfaction degree nor any of the key attributes were affected. T1 olives got the 453 highest values of: (i) typical flavor of green table olives (6.8), and (ii) what it is 454 more important of global satisfaction degree (6.8); however, the differences with 455 the other treatments were not statistically significant. The values of the consumers 456 scores for their satisfaction degree regarding these two parameters (table olive 457 flavor and global) for T0 and T2 fruits had similar values (6.5 and 6.3, 458 respectively). In affective tests consum ers normally use only the central part of the 459 scale avoiding the use of extrem e values; consequently, the value of 6.8 460 (remem ber that 7 is “like moderately”) obtained by T1 olives for the global 461 19 satisfaction degree indicate that Spanish consum ers really liked T1 “Manzanilla” 462 table olives. Perhaps the num ber of consum ers used, 100, was not high enough to 463 show significant differences am ong the RDI treatm ents; this is a topic that will 464 require further research in national and international markets. 465 Table 8 shows that RDI significantly affected several of the key sensory 466 attributes used to describe the quality of “Manzanilla” table olives; however, several 467 attributes were not affected and presented the following mean intensity values: 468 bitterness (5.7), sourness (2.4), sweetness (1.4), crunchiness (7.4), and 469 fibrousness (2.0). One thing that was highlighted by the trained panel while 470 evaluating table olives was that control fruits (T0) had pits which were easier to 471 remove from the edible portion (8.0) than other fruits (T2 = 6.8, and T1 = 7.7). I t 472 is possible that the higher water content of control olives helped panelists in 473 removing the stone of these fruits. The m ost important finding was that T1 fruits 474 had the highest intensities of saltiness (5.8), green-olive flavor (7.9), aftertaste 475 (6.4), and hardness (7.9). I t is possible that these higher intensities of T1 olives 476 were due, at least in part, to the production of a thick skin due to the lim ited water 477 availability (Patumi, d` Andria, Marisilio, Fontanazza, Morelli & Lanza 2002). On the 478 other hand, T2 olives had the lowest intensities of the previous attributes (saltiness, 479 green-olive flavor, aftertaste, and hardness). Finally, the trend shown in descriptive 480 sensory of “ Manzanilla” table olives agreed with the initial hypothesis of our study 481 (under soft water stress, T1, the plant metabolism will be activated while under 482 more severe conditions, T2, the m etabolism will be damaged. 483 20 4 . CONCLUSI ONS 484 485 This is the first study investigating the content of nutrients, antioxidant 486 activity and sensory quality of table olives obtained after regulated deficit irrigation 487 (RDI ). Table olives obtained after RDI treatm ents (T1 and T2) were m ore rounded 488 than those of the control treatment (T0), had higher intensity of green color ( a* ), 489 and presented significantly lower contents of phytic acid and calcium as com pared 490 to control olives. I n general, T1 table olives were characterized by the highest dry 491 matter and oil contents, higher intensities of key sensory attributes, and high 492 satisfaction degree am ong Spanish consum ers. In addition, T2 treatment resulted 493 in the highest percentage of polyunsaturated fatty acids (linoleic acid), green color, 494 and weight. Regarding the antioxidant activity, although no significant effect was 495 observed after the RDI treatments, it can be concluded that Spanish table olives 496 are a very good source of polyphenols and consequently have high antioxidant 497 activity. As the final conclusion, it can be stated that “soft” RDI is an effective and 498 good alternative for the irrigation of olive trees, “ Manzanilla de Sevilla”, because it 499 reduces the econom ic and environmental costs, and m aintains or even increases, in 500 som e cases, its functionality and its sensory quality and consum er acceptance. 501 502 503 ACKNOW LEDGEMENTS 504 The authors are grateful to the projects AGL2013-45922-C2-1-R y AGL2013- 505 45922-C2-2-R (Ministerio de Econom ía y Competitividad, Spain). 506 21 REFERENCES 507 Aktas, A. B., Ozen, B. Tokatli, F., & Sen, I. (2014). Com parison of som e chemical 508 apram ters of a naturally debittered olive (Olea europaea L.) type with regular 509 olive varieties. 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I rrigation effects on quality on quality, phenolic com position and 616 selected volatiles of virgin olive oils cv. Leccino. Journal of Agricultural and 617 Food Chem istry, 55, 6609-6618. 618 25 Urbano, G., López-Jurado, M., Aranda, P., Vidal-Valverde, C., Tenorio, E., & 619 Tenorio. (2000). The role of pphytic acid in legum es: antinutrient or beneficial 620 function? Journal of Physiology and Biochem istry, 56 (3), 283-294. 621 Thom pson, L. U. (1993). Potential health beneficits and problem s associated with 622 antinutrients in foods. Food Research I nternational, 26, 131-149. 623 Zhou, J. R & Erdm an, J. W. (1995). Phytic acid in health and disease. Critical 624 Reviews in Food Science and Nutrition, 35, 495-508. 625 32 Tab le 7 680 Affective sensory analysis of “Manzanilla” table olives as affected by deficit 681 irrigation treatm ent. Consum ers used a 9-point hedonic scale, where 1 = dislike 682 extrem ely, 5 = neither like nor dislike, 9 = like extrem ely. 683 684 Par am et er AN OVA a T0 T1 T2 Fresh table olive flavor NS 6.5 6.8 6.4 Bitterness NS 6.3 6.4 6.1 Saltiness NS 6.0 6.4 6.2 Hardness NS 7.4 7.3 6.9 Crunchiness NS 7.5 7.3 6.9 Aftertaste NS 6.4 6.4 6.2 GLOBAL NS 6.5 6.8 6.3 a NS = not significant at p< 0.05; * , * * , and * * * , significant at p< 0.05, 0.01, and 685 0.001, respectively. 686 b Values are the m ean of 100 consum ers. 687 33 Tab le 8 688 Descriptive sensory analysis of “Manzanilla” table olives as affected by regulated 689 deficit irrigation treatm ent. Trained panelists used a scale from 0 = no intensity to 690 10 = extremely strong intensity. 691 692 Par am et er a ANOVA b T0 T1 T2 FLAVOR Saltiness * * 4.8 b c 5.8 a 4.9 b Bitterness NS 5.3 5.8 6.1 Sourness NS 2.3 2.6 2.2 Sweetness NS 1.3 1.4 1.4 Green-olive flavor * 7.0 ab 7.9 a 6.3 b Aftertaste * 5.4 ab 6.4 a 5.2 b TEXTURE Hardness * * 7.0 ab 7.9 a 6.4 b Crunchiness NS 7.1 7.9 6.9 Fibrousness NS 2.1 1.8 1.9 Pit removal * 8.0 a 7.7 ab 6.8 b a Attributes included in this profile are based on I OOC (2011); 693 b NS = not significant at p< 0.05; * , * * , and * * * , significant at p< 0.05, 0.01, and 694 0.001, respectively. 695 c Values (m ean of 10 trained panelists) followed by the sam e letter, within the same 696 row, were not significantly different (p< 0.05), according to Tukey’s least significant 697 difference test. 698