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Bruising pattern of table olives (‘Manzanilla’ and ‘Hojiblanca’ cultivars) caused by hand-held machine harvesting methods

Sola Guirado, Rafael R.,Bayano Tejero, Sergio,Aragón Rodriguez, Fernando,Peña Fernández, Ana Araceli,Blanco Roldan, Gregorio

Abstract

This work presents a characterisation of the fruit and the bruising caused by some common detachment methods (manual, stick, shaker comb, branch shaker) and interception methods (net or padding) in common table olive varieties. We took pictures of fruit samples inside a special device, and the images were processed to extract characteristic parameters of shape and size (number of spots, Feret diameter, circularity, colours …). Moreover, we studied the time evolution of bruising caused on the fruit by a controlled impact. Finally, we developed a system that allows synchronised rotation of the fruit with image capture to evaluate bruising on the whole volume of the fruit. Our results showed that different harvesting treatments produced differences in the average number and diameter of spots per fruit, as well as in the average area of the spots per fruit for the different varieties. Fruit colour or bruising can also serve as a control factor for computer vision characterisation, for which reason we recorded differences in the firmness of the bruised and non-bruised areas of fruit. The harvesting method that caused the highest median values of bruise index was the shaker comb, particularly for ‘Manzanilla’ with an index of 1.59% on padding compared to 0.24% for ‘Hojiblanca’. Net interception was also observed to increase the bruise index in ‘Manzanilla’ (5.85%). Bruising assessment that only considers a single photograph means that a considerable amount of bruising remains disregarded compared to the actual bruising on the whole volume of the fruit

Full text

Resea ch Pape B uising pa e n o able oli es (‘Manzanilla’ and ‘Hojiblanca’ cul i a s) caused by hand-held machine ha es ing me hods Ra ael R. Sola-Gui ado a,* , Se gio Bayano-Teje o b , Fe nando A agon-Rod iguez b , A aceli Pe~ na c , G ego io Blanco-Roldan b a Depa men o Mechanics, Uni e si y o Co doba, Campus de Rabanales, Co doba, Spain b Depa men o Ru al Enginee ing, Uni e si y o Co doba, Campus de Rabanales, Co doba, Spain c Resea ch Cen e CIAIMBITAL, Uni e si y o Alme ı´a, Alme ı´a, Spain a icle in o A icle his o y: Recei ed 24 May 2021 Recei ed in e ised o m 7 Janua y 2022 Accep ed 12 Janua y 2022 Published online 28 Janua y 2022 Keywo ds: B uise index Colou Damage F ui cha ac e isa ion Mechanical ha es ing Olea eu opaea This wo k p esen s a cha ac e isa ion o he ui and he b uising caused by some com- mon de achmen me hods (manual, s ick, shake comb, b anch shake ) and in e cep ion me hods (ne o padding) in common able oli e a ie ies. We ook pic u es o ui samples inside a special de ice, and he images we e p ocessed o ex ac cha ac e is ic pa ame e s o shape and size (numbe o spo s, Fe e diame e , ci cula i y, colou s …). Mo eo e , we s udied he ime e olu ion o b uising caused on he ui by a con olled impac . Finally, we de eloped a sys em ha allows synch onised o a ion o he ui wi h image cap u e o e alua e b uising on he whole olume o he ui . Ou esul s showed ha di e en ha es ing ea men s p oduced di e ences in he a e age numbe and diame e o spo s pe ui , as well as in he a e age a ea o he spo s pe ui o he di e en a ie ies. F ui colou o b uising can also se e as a con ol ac o o compu e ision cha ac e isa ion, o which eason we eco ded di e ences in he i mness o he b uised and non-b uised a eas o ui . The ha es ing me hod ha caused he highes median alues o b uise index was he shake comb, pa icula ly o ‘Manzanilla’ wi h an index o 1.59% on padding compa ed o 0.24% o ‘Hojiblanca’. Ne in e cep ion was also obse ed o inc ease he b uise index in ‘Manzanilla’ (5.85%). B uising assessmen ha only conside s a single pho og aph means ha a conside able amoun o b uising emains dis ega ded compa ed o he ac ual b uising on he whole olume o he ui . ©2022 The Au ho (s). Published by Else ie L d on behal o IAg E. This is an open access a icle unde he CC BY-NC-ND license (h p://c ea i ecommons.o g/licenses/by-nc-nd/4.0/). *Co esponding au ho . E-mail add ess: [email p o ec ed] (R.R. Sola-Gui ado). A ailable online a www.sciencedi ec .com ScienceDi ec jou nal homepage: www.else ie .com/loca e/issn/15375110 biosys ems enginee ing 215 (2022) 188e202 h ps://doi.o g/10.1016/j.biosys emseng.2022.01.010 1537-5110/©2022 The Au ho (s). Published by Else ie L d on behal o IAg E. This is an open access a icle unde he CC BY-NC-ND license (h p://c ea i ecommons.o g/licenses/by-nc-nd/4.0/). 1. In oduc ion The cul i a ion o he oli e ee (Olea eu opaea L.) enjoys sus- ained g ow h a a global le el, cu en ly eaching 10.5 Mha (FAO, 2019). Sligh ly less han hal o he o al p oduc ion, 2.9 million onnes, is des ined o able oli es. Spain plays a majo ole in he able oli e sec o , wi h a p oduc ion o 0.5 million onnes (IOC., 2020). The ‘Manzanilla’, ‘Go dal’ and ‘Hojiblanca’ cul i a s (Campus, Degi mencioglu, &Comunian, 2018) a e he mos common comme cial a ie ies due o hei good pulp/pi a io, and g een p ocessing is one o he mos com- mon me hods employed o able oli es. The Spanish s yle, which p edomina es in his me hod (S anchez-G omez, Ga cı´a- Ga cı´a, &Ga ido-Fe n andez, 2013;Royal Dec ee 679/2016), means ha any ui de ec s equi e special a en ion as hey in luence quali y and, he e o e, he p ice ui can a ain on he ma ke . Any spo s on he ui 's su ace will de e mine i s ca ego y o comme cialisa ion (Royal Dec ee 679/2016Royal Dec ee 679/2016). Such de ec s can be classi ied acco ding o hei o igin (Riquelme, Ba ei o, Ruiz-Al isen , &Vale o, 2008), and b uising cons i u es he cha ac e is ic ype o damage p oduced du ing ha es ing. Mechanical ha es ing conside ably inc eases he le el o damage o esh ui such as able oli es (Hussein, Fawole, & Opa a, 2020). The main objec i e o he manual ha es ing conduc ed in mos able oli e o cha ds is o educe damage o he ui . This causes a conside able loss o p o i abili y since manual ha es ing me hods compe e wi h he highly mech- anised sys ems employed in mode n oli e g owing o he new in ensi ied plan ing sys ems. Ad ances in his ield a e o ien ed owa ds comp ehensi e mechanisa ion using com- bined ha es ing machine y (Fe guson e al., 2010;Sola- Gui ado, Cas illo-Ruiz, Blanco-Roldan, Gonzalez-Sanchez, & Cas o-Ga cı´a, 2020) and pos -ha es sys ems (Rejano, Mon a~ no, Casado, S anchez, &De Cas o, 2010;Zipo i, Fishman, Zelas, Subbo in, &Dag, 2021). In many a ming con ex s, mechanisa ion is no a alid solu ion due o he exis ing o og aphy, he small size o he a m o a lack o e- sou ces, all o which make he in oduc ion o machine y di icul . The only al e na i e on hese a ms is ha es ing wi h semi-mechanised sys ems (Be na di e al., 2018) such as b anch shake s and shake combs, o adi ional me hods like bea ing o hand picking, in which he ui alls on o ne s o suspended sys ems. These semi-mechanised ha es ing sys- ems de ach he oli e in a di e en way, so i seems logical o hink hey will also p oduce a di e en damage pa e n. Simila ly, since damage is ela ed o he le el o ene gy hey ecei e (Jim enez-Jim enez, Cas o-Ga cı´a, Blanco-Rold an, Agu ¨e a-Vega, &Gil-Ribes, 2012), he e may be a ela ionship wi h he in e cep ion sys em, due o he co ela ion be ween damage and he heigh o he oli e d op (Sa acoglu, Uce , & Oza slan, 2011). Opa a and Pa ha e (2014) lis di e en p ocedu es o cha ac e ise damage in di e en esh ui . Non-des uc i e echniques such spec al imaging, nuclea echniques, he - mal imaging and ul asound imaging, among o he s, ha e a g ea po en ial o de e mine he in e nal p ope ies o ui and de ec b uising (S ella e al., 2015;Mohammed Raju, Janna , Wang-Hee, Changyeun, &Byoung-Kwan Cho;Du e al., 2020). Compu e ision echniques a e mo e limi ed in ha hey can only cha ac e ise ex e nal damage o esh ui . Howe e , o he cha ac e isa ion o g een oli es ha will be p ocessed Spanish s yle (Campus e al., 2018), isible spec al imaging may be su icien o pe o m b uise cha ac e isa ion wi h adi ional, low-cos echnologies. Su ace damage means any de ec in he exoca p o a ui , and may be asso- cia ed wi h damage o he inne mos laye s, so damage migh be isible and measu able (Li &Thomas, 2014). I is di icul o es ablish empi ical o mula o he quan i ica ion o b uising, which depends on di e en pa ame e s such as a ie y and ma u i y s a us among o he s. A p ope cha ac e isa ion should ake in o accoun he amoun , shape and colou o he damage. B uise a ea is pa icula ly sui able o he quan i a i e cha ac e isa ion o damage. I he ela ionship be ween he b uise a ea and he o e all ui a ea is conside ed (Jim enez- Jim enez, Cas o-Ga cı´a, Blanco-Rold an, Gonz alez-S anchez, & Gil-Ribes, 2013) i is possible o es ablish a b uise index (BI). This classi ica ion allows o a quan i a i e quali ica ion o he damage, wi hou es ablishing disc e e le els, as p oposed by Hadi, Ahmad, &Akande, 2009. I is impo an o ake special ca e o quan i y ui b uising o e he o al su ace a ea o he ui . (Co kidi, Balde as-Ruı´z, Taboada, Se ano-Ca e on, & Galindo, 2006). The ela ionship o b uise index wi h he mos commonly employed able oli e ha es ing sys ems would p o ide aluable in o ma ion o imp o e he quali y o mech- anisa ion. Likewise, ano he pa ame e o in e es could be he cha ac e isa ion o he shape o damage in oli es, in line wi h he conside a ions o o he au ho s ega ding b uise calcula- ion in o he ui s (Ki hawee, Pa ha ee a , S i ung uang, & Slaugh e , 2011;Mohammed e al., 2017;Van Zeeb oeck e al., 2007). Image analysis can also de e mine he colou and ipe- ness o oli es (Guzm an, Bae en, Pie na, &Ga cı´a-Mesa, 2015). O he s udies (Beyaz, Ma ı´nez Gila, G omez O ega, &G amez Ga cı´a, 2019) indica e he in e es o applying simila me hods o de e mine he colou o he ype o ui damage known as b owning in he segmen a ion o oli e damage. B uising is changeable and equi es he s udy o i s e olu ion om i s beginning (Jim enez-Jim enez, Cas o-Ga cı´a, Blanco-Rold an, Gonz alez-S anchez, &Gil-Ribes, 2013). To de e mine oli e b uising quan i a i ely and quali a- i ely, isible imaging sys ems wi h compu e echniques ha e shown g ea po en ial o delimi ing he b owned ui a eas a e ha es ing (Jim enez-Jim enez, Cas o-Ga cı´a, Blanco-Rold an, Gonz alez-S anchez, &Gil-Ribes, 2013;Beyaz, € Ozkaya, & _ Ic¸en, 2017;Ponce, Aquino, Millan, &Anduja , 2019). The aim o his a icle is o cha ac e ise he ui and he b uise ha occu in g een able oli es, speci ically he ‘Hojiblanca’ and ‘Manzanilla’ a ie ies, employing compu e ision echniques a e he use o common ha es ing me hods. These pa ame e s we e e alua ed when ex e nal damage had s abilised and, in addi ion, du ing empo al e olu ion. The compa ison o damage quan i ica ion also ook in o accoun he en i e su ace o he ui e sus only one side o he ui . biosys ems enginee ing 215 (2022) 188e202 189 2. Ma e ials and me hods We conduc ed a se ies o ials, which consis ed o ha es ing oli es acco ding o di e en ea men s and analysing he pa e n o ex e nal damage caused o he ui s by means o image analysis. 2.1. Ob aining images o cha ac e ise he oli es The oli e samples we e placed in 0.18 m squa e polylac ic acid (PLA) ays, co e ed in blue oam wi h ellipsoid pe o a ions o he placemen o 20 ui s (Fig. 1). The samples we e placed in a closed ligh ing de ice (Sola-Gui ado, Bayano-Teje o, e al., 2020) wi h con olled ligh ing 13.95 ±0.57 lux, and a colou empe a u e o 5500 K om 4 LED ba s on he loo a 30, wi h di used ligh ing. A digi al came a (Nikon, D80, Tokyo, Japan) was placed o e o he samples, 570 mm abo e he ay su - ace, o ake pho og aphs a an ape u e se ing o /6.3, shu e speed E:1/125 s, ligh sensi i i y ISO:160, ocal leng h FL: 35 mm, and exposu e compensa ion EB:-1 EV. The eso- lu ion o each pho og aph was 3872 2592 pixels pe ay a ea wi h a ui esolu ion o 226 197 pixels. Each pho og aph was digi ally p ocessed by an expe using ImageJ so wa e (Na ional Ins i u e o Men al Heal h) o cha ac e ise he ui and i s b uised a ea. To do his, he pic u e was i s cu o ob ain 20 indi idual pho og aphs o each ui , iden i ied acco ding o i s ea men . Segmen a ion con e ed each pho og aph in o a bina y image o ex ac he ui measu emen s. Then, by adding he bina y pho o o he o iginal ui pho o, he backg ound was emo ed, lea ing only he ui . Finally, he b uised a ea o each ui was manually segmen ed o ob ain ano he pho og aph wi h he b uising a eas. Analysis o he pic u es epo ed he ollowing use ul pa ame e s o cha ac e ising he ui and b uising pa e n: - F ui and b uise a ea (mm 2 ): he a e age numbe o pixels o each ui o b uise scaled wi h i s pixel- o- millime e con e sion. - B uise index (%), BI: a io be ween he o al b uise a ea o each ui and i s ui a ea. - F ui leng h and diame e (mm). La ges and smalles dis ance be ween wo poin s on he ui a ea, usually coinciding wi h he majo and mino diame e s o he ellip ical shape o he ui . - Maximum Fe e diame e (mm) o he b uise spo : longes dis ance be ween any wo poin s along he spo selec ion bounda y. - Ci cula i y (#): he oundness o simila i y o a pe ec ci cle o he ui o b uised spo , which a ies om 0 o 1, wi h 0 co esponding o an in ini ely elonga ed poly- gon and 1 o a pe ec ci cle. - Numbe o spo s: numbe o b uised spo s pe ui . - Colou : coo dina es on he a e age RGB colou space o he pixels o each ui wi hou aking in o accoun he b uised a ea, o o he b uised spo i sel . 2.2. Ha es ing ea men s o ees and oli e samples We conduc ed he ials on wo di e en plo s o ‘Manzanilla’ able oli es and ano he wo plo s o ‘Hojiblanca’ des ined o g een p ocessing, loca ed in Co doba (Spain) du ing he mon hs o Sep embe and Oc obe o he 2018/19 and 2019/20 ha es ing campaigns. The ees we e unde i iga ion and wi hou bio ic o abio ic s ess. The ha es ing sys ems used o de ach he ui we e hose habi ually employed o his pu pose: manual picking (M) as a e e ence ea men , manual bea ing wi h a long ibe glass pole (B), semi-mechanised wi h a b anch shake (BS) (S ihl, SP 481, Waiblingen, Ge many), and semi-mechanised wi h a shake comb (SC) (Pellenc, P230, Pe uis, F ance). The ib a ion signals p oduced by he ha - es ing me hods on he main b anches we e eco ded using a MEMS iaxial accele ome e (Gul Coas Da a Concep s LLC X200-4, Wa eland, MS), wi h a measu emen ange o ±2000 ms 2 , a sensi i i y o 0.06 m s 2 and a sampling equency o 400 Hz. Table 1 summa ises he ib a ion pa e ns ha cha - ac e ised hese sys ems on he b anches. Each ee was ha - es ed om b anches loca ed be ween 1.5 and 2.4 m abo e he Fig. 1 eT ay wi h impac ed ui and sequence o impac caused by ee- all o he ball. biosys ems enginee ing 215 (2022) 188e202190 g ound by a a m wo ke , using he usual echnique employed on he plo . An ag icul u al ex ile ne ing (N), as usually used in oli e ha es ing, was placed on he loo , along wi h a padding su ace (P), consis ing o wo laye s o 3 mm hick poly inyl chlo ide illed wi h ai wi h a diame e o 1 m a a heigh o 0.1 m. Oli e samples we e aken om he padding o s udy he exclusi e incidence o he de achmen me hod. In he case o he ‘Manzanilla’, a ie y, which has g ea e suscep ibili y o b uising (Jim enez-Jim enez, Cas o-Ga cı´a, Blanco-Rold an, Gonz alez-S anchez, &Gil-Ribes, 2013), sam- ples we e also aken om he ne in a eas a om he padding o s udy he incidence o he in e cep ion means on his a ie y. In addi ion, andomly hand-collec ed samples wi hou ex e nal damage we e ha es ed and an impac o hi (H) was applied o he cen e o he ui . To pe o m he impac , a de ice was used in ee all om a heigh o 0.125 m wi h a s eel ball ha had a mass o 0.035 kg, applying an en- e gy o 0.043 J (Fig. 1). The ollowing ea men s we e he eby ob ained: MP, BS-P, SC-P, BeP o ‘Hojiblanca’ and MN, MP, BS-N, BS-P, SC-N, SC-P, BeN, BeP o ‘Manzanilla’ and H o bo h a i- e ies. The samples ob ained in each o he ea men s, we e kep d y a an a e age empe a u e o 23 C and pho o- g aphed 150 min a e ha es ing, when he b uise had s abilised (Jim enez-Jim enez, Cas o-Ga cı´a, Blanco-Rold an, Gonz alez-S anchez, &Gil-Ribes, 2013)., a oiding hose ha ci cumsc ibe he pe ime e o he plo . Th ee ows o ees we e andomly selec ed and, in each ow, h ee ees we e again andomly selec ed o apply he ea men s (1 ee exclusi ely used o 1 ha es ing me hod). When selec ing ows, hose co esponding o he pe ime e o he plo we e disca ded, as we e he ees a he beginning and end o he ow. Twen y ui samples (1 ay) we e aken om each ee o each ea men (BSeP, SC-P, BeP, BS-N, SC-N, BeN), esul ing in a o al 60 samples pe ea men and day. T ea men s wi h a common ha es ing me hod we e applied on he same ee, and samples we e ha es ed simul a- neously using he ne o padding su ace. Fo he e e ence ea men (M), oli es we e andomly ha es ed om he 3 ees in he ow be o e applica ion o he ea men s. In case o impac ea men (H), I oli e samples we e also collec ed om he 3 ees o he ea men s in he ow, on di e en a eas o he ee and wi hou p e ious b uising. These ials we e epea ed 4 imes pe campaign and plo , spaced app oxima ely 5 days apa , lea ing a minimum di e ence o 4 days in he e en o ain all. 2.3. Cha ac e isa ion o oli es and hei ex e nal damage We conduc ed di e en ypes o s udies o de e mine use ul pa ame e s o modelling oli es and hei b uising: 1. Size and shape cha ac e isa ion: Se e al geome ical pa ame e s we e aken o he ui (leng h, diame e , and ci cula i y), o he b uised spo s hey had (numbe o spo s, Fe e diame e and ci cula i y) and o all ea men s, ex ac ing he in o ma ion om image analysis. In addi ion, he ui mass (g) was measu ed wi h a digi al scale (G am, EH-500, Spain). 2. Fi mness assessmen : The pene a ion o ce needed o b eak he ui su ace was measu ed wi h a pene- ome e using a cylind ical 3 mm long and 2.4 mm diame e ip (IMADA Inc., DS2-11, USA) in non-b uised and b uised a eas ( he la e om spo a eas g ea e han 16 mm 2 ). 3. Colou de e mina ion: The colo ime ic cha ac e is ics o he oli e in ui a eas wi h damage (spo a ea g ea e han 16 mm 2 ) and wi hou damage we e measu ed o all ea men s using a colo ime e (Konica Minol a, CR- 400, USA) calib a ed wi h a D65 2illumina ion measu ed in CIELAB colou space. Simila ly, we de e - mined he RGB colou coo dina es o he images p ocessed. 4. B uise index and i s ime e olu ion: The b uise index was de e mined 150 min a e ha es ing o all ea - men s, using image analysis o ex ac he ui a ea and damage a ea. Mo eo e , images o he ui impac ed wi h he ee- all de ice (H) we e aken e e y 15 min up o 150 min, o e alua e he de elopmen o b uising o e ime. 5. Loca ion o he b uising on he su ace o he ui : Calcula ion o he b uise index no mally uses a single image, igno ing wha occu s in he unseen a eas, conside ing he ellipsoid geome y o he oli es. To e alua e ui b uising conside ing he en i e su ace o he ui , we designed a p o o ype (Fig. 2) o o a e he oli es on hei main axis. The de ice consis s o se e al gea s, wi h wo needles in hei cen es, whe e andomly selec ed ui samples a e placed. We e alu- a ed 60 ui samples pe ha es ing ea men and a- ie y, 150 min a e hei ha es . A mo o (4076 s eps pe u n) con olled by a mic ocon olle (A duino, Nano, I aly) o a ed he ui , shi ing 15a a ime o ake 24 pic u es pe ui in each posi ion o he e olu ion. To de e mine he amoun and loca ion o he b uising p oduced o e he whole su ace, he pic u es we e p ocessed o gi e a comple e wo-dimensional ep esen a ion o he oli e wi hou de o ma ion (Fig. 3): a. Each o he cap u ed images was c opped o a oid o e lapping o he same a ea, ci cumsc ibing an ellipse whose majo diame e coincided wi h he ui leng h Table 1 eVib a ion pa ame e s o ui -bea ing b anches wi h ha es ing sys ems. Ha es ing me hod Mean esul an accele a ion (m$s 2 ) F equency (Hz) S ick bea ing 560.7 ±214.3 a e Shake Comb 79.6 ±42.6 14.0 ±0.4 B anch shake 209.3 ±81.1 20.6 ±1.1 Values showed a e mean ±s anda d de ia ion. a Mean peak alue. biosys ems enginee ing 215 (2022) 188e202 191 and whose mino diame e is he ui pe ime e ðp∙diame e Þdi ided by 24. b. Each cu was joined o he consecu i e one. c. All pixels o he composi ion a e g ouped oge he o gi e con inui y o he composi ion while main aining he equa o ial line cons an . d. The emaining composi ion was enla ged by p ojec ion on o he cu a u e o he ellipse in he on iew, i.e. by making he dis ance be ween he peduncle and i s an- ipode coincide wi h hal he pe ime e o he ellipse de e mined in he on iew. In all cases, we in es iga ed he ela ionship ha exis s o all o he s udied a iables wi h bo h he ha es ing me hod and he in e cep ion me hod (in he case o ‘Manzanilla’). We also analysed he di e ences be ween he di e en a ie ies be o e inally s udying ela ionships exis ing wi hin he di e en s udy pa ame e s. 3. Resul s 3.1. F ui and ui b uising size and shape cha ac e isa ion Table 2 shows he cha ac e isa ion o shape and size o he ui s sampled o he wo ha es ing seasons acco ding o he di e en me hods. F ui mass, leng h and diame e a iables showed a no mal dis ibu ion (Kolmogo o eSmi no , p >0.05) o bo h a ie ies. A compa ison o he ha es ing me hods (ANOVA es , p >0.05; pos -hoc Tukey es , p >0.05) showed no signi ican di e ences in he a iables o mass, leng h and diame e o he wo a ie ies and seasons, no did we ind any signi ican di e ences be ween he ne and padding ca ching sys ems (ANOVA es , p >0.05; pos -hoc Tukey es , p >0.05). Howe e , we did ind signi ican di e ences (S uden 's - es , p<0.05) wi hin each a ie y in he compa ison o he 2019 and 2020 seasons: The diame e and leng h o ui o bo h a ie ies showed a s ong posi i e co ela ion wi h ui mass (‘Hoji- blanca’: Pea son Coe icien ¼0.88; Pea son Coe icien ¼0.89; p<0.05; ‘Manzanilla’: Pea son Coe icien ¼0.88; Pea son Coe icien ¼0.91; p <0.05). Ci cula i y did no show a no mal dis ibu ion (Kolmogo o eSmi no , p <0.05). Signi ican di - e ences we e ound in ci cula i y be ween a ie ies (Wilcox- oneManneWhi ney Tes , p <0.05), wi h a median alue and in e qua ile ange in ‘Hojiblanca’ o 0.865 (0.023) and 0.869 (0.026) in ‘Manzanilla’,wi h di use di e ences be ween ha - es ing me hods. Table 3 shows some ep esen a i e pa ame e s o he cha ac e is ic size and shape o he ui b uising spo s. The numbe o spo s pe ui did no ollow a no mal dis ibu ion. Fo bo h seasons and a ie ies, he numbe o spo s was signi ican ly di e en (K uskaleWallis, p <0.05) be ween he manual me hod and he o he de achmen me hods (pos -hoc Wilcoxon ank sum es wi h Holm adjus men , p <0.05), in which he e we e no di e ences be ween hem (pos -hoc Fig. 2 eDe ice de eloped o u ning oli es and aking images om di e en sides. biosys ems enginee ing 215 (2022) 188e202192 Wilcoxon ank sum es wi h Holm adjus men , p >0.05). In all cases, he numbe o spo s wi hin he same de achmen me hods inc eased in he ne ca ching compa ed o padding ca ching. The ci cula i y o spo s was signi ican ly di e en be ween de achmen me hods o ‘Manzanilla’ and ‘Hoji- blanca’ (K uskaleWallis, p <0.05; pos -hoc Wilcoxon ank sum es wi h Holm adjus men , p <0.05), and was lowe o he la e in all cases. The mean g ea e Fe e diame e o he spo was di e en (K uskaleWallis, p <0.05; pos -hoc Wilcoxon ank sum es wi h Holm adjus men , p <0.05) be ween a i- e ies and de achmen me hods, and sligh ly g ea e in ‘Hoji- blanca’, excep o he shake comb, whe e hey we e he same. 3.2. Fi mness assessmen Pene a ion o ce alues in he b uised and non-b uised ui zones ollowed a no mal dis ibu ion (Kolmogo o eSmi no , p>0.05) o bo h a ie ies. Signi ican di e ences (S uden 's - es , p <0.05) we e ound be ween he b uised and non- b uised ui zones in bo h a ie ies, wi h a alue o 14.02 ±1.92 N and 10.26 ±1.73 N o he b uised zone in ‘Hojiblanca’ and ‘Manzanilla’, espec i ely, and a alue o 17.11 ±1.73 N and 13.02 ±1.32 N o he non-b uised zones, in '‘Hojiblanca’ and ‘Manzanilla’, espec i ely. Wi hin each a- ie y he e we e also signi ican di e ences be ween he Fig. 3 eP ocess pe o med o he ep esen a ion o he en i e su ace o an oli e om he 24 pho os o a ui o a ed 15. Table 2 eF ui size and shape alues measu ed in wo ha es ing seasons acco ding o de achmen me hod wi h padded ca ching and oli e a ie y. De achmen me hod Va ie y Mass (g) a Leng h a Diame e a Ci cula i y b Manual ‘Hojiblanca’ 3.64 ±0.84 a 22.42 ±2.01 a 17.71 ±1.49 a 0.869 (0.024) a ‘Manzanilla’ 4.22 ±1.00 b 22.72 ±2.27 abc 18.62 ±1.86 b 0.877 (0.024) b B anch shake ‘Hojiblanca’ 3.58 ±0.83 a 22.43 ±2.02 a 17.60 ±1.56 a 0.864 (0.021) c ‘Manzanilla’ 3.91 ±0.98 c 22.92 ±2.11 bd 18.47 ±1.63 b 0.866 (0.026) ac Shake comb ‘Hojiblanca’ 3.56 ±0.70 a 22.36 ±1.64 a 17.68 ±1.35 a 0.863 (0.024) c ‘Manzanilla’ 3.90 ±0.97 c 22.59 ±2.13 ab 18.25 ±1.78 b 0.867 (0.025) a S ick bea ing ‘Hojiblanca’ 4.78 ±0.86 d 23.32 ±1.83 d 19.38 ±1.41 c 0.878 (0.021) b ‘Manzanilla’ 4.74 ±0.79 d 23.16 ±1.62 cd 19.35 ±1.34 c 0.879 (0.022) b Values shown a e mean ±s anda d de ia ion o he median and he in e qua ile ange in b acke s. Di e en le e s be ween ows o he same column indica e signi ican di e ences acco ding o. a No mal dis ibu ion (ANOVA, p <0.05; pos hoc pai wise wi h pooled s anda d de ia ion and Holm adjus men me hod, p <0.05) o . b Non-no mal dis ibu ion (K uskaleWallis, p <0.05; pos hoc Wilcoxon ank sum es wi h Holm adjus men me hod, p <0.05). biosys ems enginee ing 215 (2022) 188e202 193 b uised and non-b uised zones (pai ed - es , p <0.05), wi h an a e age educ ion in pene a ion o ce o 18% o ‘Hojiblanca’ and 21% o '‘Manzanilla’. In e ms o ha es ing me hods, he ui s o bo h a ie ies ollowed he same end in he non-b uised zones. The e we e signi ican di e ences o pene a ion o ce be ween he manual me hod, which had he highes alue, and he o he ha es ing me hods (ANOVA es , p <0.05; pos -hoc Tukey es , p <0.05). In he non-b uised zone, no di e ences we e ound be ween he b anch shake and shake comb o ‘Hojiblanca’ (S uden 's - es , p >0.05), wi h alues o 14.91 ±1.68 N and 14.10 ±1.94 N, espec i ely, whe eas di - e ences we e ound be ween hese me hods o '‘Manzanilla’ (S uden 's - es , p <0.05), wi h alues o 11.82 ±1.05 N and 9.73 ±1.61 N. A posi i e co ela ion o ui pene a ion o ce wi h ui weigh (Pea son coe icien p <0.05) was ound o bo h a ie ies in manual ha es ing me hods, conside ing ha he ui measu ed a e des ined o g een p ocessing. Pene a ion o ce alues in he non-impac ed zone o he ui showed a iabili y o e ime. Signi ican di e ences we e ound in bo h a ie ies be ween he i s ou weeks and he i h and six h weeks (ANOVA, pos -hoc Tukey p <0.05; K uskall-Wallis, pos -hoc WilcoxoneManneWhi ney Tes p<0.05). We obse ed ha he p opo ion o ui s wi h a highe ma u i y (highe Jaen index), inc eases as weeks go by (da a no shown). In addi ion, he alue o hei pene a ion o ce was di e en among ui s, excep o hose wi h indices o 0 and 1 (ANOVA, pos -hoc Tukey p <0.05; K uskall-Wallis, pos -hoc WilcoxoneManneWhi ney Tes p <0.05), which dec eased in alue as he ma u i y index inc eased. 3.3. F ui and ui b uising colou cha ac e isa ion Table 4 shows he componen s o CIELAB colou space measu ed wi h he colo ime e on he ui samples es ed. The alues o he ‘a’ componen showed no di e ences be- ween he di e en campaigns o each a ie y (Wilcox- oneManneWhi ney Tes , p >0.05), unlike he ‘L’ and ‘b’ componen s, which we e di e en o each a ie y (Wilcox- oneManneWhi ney Tes , p <0.05). In addi ion, we obse ed no signi ican di e ences be ween he di e en mechanised ha es ing me hods o be ween he padding o ne in e - cep ion me hods. The alues o all componen s we e highe in ‘Manzanilla’ han in ‘Hojiblanca’ in bo h seasons. In bo h a ie ies, nega i e ela ionships we e measu ed be ween he ‘a’ and ‘b’ componen o he CIELAB colou space (Spea man ho, p <0.05) wi h signi ican ela ionships ela ed o ui mass and diame e s (Pea son coe icien , p <0.05; Spea man ho, p <0.05) o ‘Manzanilla’. Al hough his s udy only e alua ed g een ui s, when conside ing di e en ma u i y indices, he analysis o he ui colou in RGB space ex ac ed om he pho og aphs shows a end o colou e olu ion om deep g een o black. (Fig. 4). F ui colou o e he six di e en weeks s udied was signi ican ly di e en (K uskall-Wallis, p<0.05) o each o he channels (RGB), wi h di e en ed and g een channel alues o each week (pos -hoc Wilcox- oneManneWhi ney Tes wi h Holm co ec ion, p <0.05). 3.4. B uise index cha ac e isa ion B uise index 150 min a e ha es ing The b uise index did no ollow a no mal dis ibu ion (Kolmogo o eSmi no , p <0.05). Figu e 5 shows he median alues ob ained o he wo a ie ies and he ha es ing ea men s udied. The e we e signi ican di e ences (Wil- coxoneManneWhi ney Tes , p <0.05) o he wo seasons be ween ‘Hojiblanca’ and ‘Manzanilla’ wi h g ea e damage su e ed by ‘Manzanilla’. Conside ing exclusi ely de achmen me hod, i.e. compa ing padding ea men s, he e we e no signi ican di e ences be ween a ie ies using he manual me hod and manual bea ing wi h s ick (K uskaleWallis, p<0.05; pos -hoc Wilcoxon ank sum es wi h Holm adjus - men , p <0.05). Howe e , signi ican di e ences we e ound be ween a ie ies using he b anch shake (BI ¼0.03 o ‘Hojiblanca’ and BI ¼0.33 o ‘Manzanilla’) o he shake comb (BI ¼0.24 o ‘Hojiblanca’ and BI ¼1.59 o ‘Manzanilla’), wi h signi ican di e ences be ween bo h me hods o he same a ie y (pos -hoc Wilcoxon ank sum es wi h Holm adjus - men , p <0.05). Rega ding he in e cep me hod, i.e., compa ing he same de achmen me hod be ween padding and ne , we ound di e ences o all sys ems, which we e Table 3 eF ui b uised spo size and shape alues measu ed in wo ha es ing seasons acco ding o ha es ing me hod and oli e a ie y. De achmen me hod Ca ching me hod Va ie y Numbe o spo s Fe e Diame e (mm) Ci cula i y Manual Padded ‘Hojiblanca’ 0 (1) a 2.35 (2.10) a 0.709 (0.235) ab Padded ‘Manzanilla’ 0 (1) a 1.62 (2.20) b 0.788 (0.314) c Ne 2 (3) b 2.21 (2.01) ab 0.674 (0.233) ab B anch shake Padded ‘Hojiblanca’ 1 (2) c 1.53 (1.10) b 0.725 (0.205) a Padded ‘Manzanilla’ 2 (5) b 1.34 (0.83) c 0.787 (0.191) c Ne 3 (4) d 1.99 (1.42) b 0.704 (0.198) ab Shake comb Padded ‘Hojiblanca’ 1 (2) c 3.04 (2.60) d 0.628 (0.211) d Padded ‘Manzanilla’ 2 (3) b 2.79 (2.16) ad 0.677 (0.201) b Ne 3 (2) d 4.41 (2.37) e 0.580 (0.162) e S ick bea ing Padded ‘Hojiblanca’ 0 (2) ac 2.08 (2.61) ab 0.666 (0.379) abd Padded ‘Manzanilla’ 0 (3) ac 2.37 (2.18) abd 0.664 (0.328) abd Ne 2 (3) b 2.28 (2.34) abd 0.628 (0.305) abd The alues ep esen ed a e median and in e qua ile ange. Di e en le e s indica e signi ican di e ences be ween ows o he same column (K uskaleWallis, p <0.05; pos -hoc Wilcoxon ank sum es wi h Holm adjus men me hod, p <0.05). biosys ems enginee ing 215 (2022) 188e202194 signi ican ly highe wi h a ne in e cep (K uskaleWallis, p<0.05; pos -hoc Wilcoxon ank sum es wi h Holm adjus - men , p <0.05). The highes alues we e ound using he shake comb o bo h seasons and a ie ies wi h g ea e alues in ‘Manzanilla’ (BI ¼1.59 o padding and BI ¼5.85 o ne ). I is possible o make a nominal classi ica ion by placing b uise index limi s (BI ¼0, 0<BI <1, 1<BI <3, 3<BI <5, BI >5) in o de o compa e he le el o damage s udied by o he au- ho s (Cas o-Ga cia, Cas illo-Ruiz, JimenezeJimenez, Gil- Ribes, &Blanco-Roldan, 2015: no damage, sligh damage, mode a e damage, se e e damage, mu ila ed). Howe e , his is only a p oposal o h esholds since hese au ho s used a isual classi ica ion so did no quan i y he a ea o b uising used o de ine he limi s. Figu e 6 shows he dis ibu ion o b uising in he sampled ui wi h ou p oposed classi ica ion. Wi h he h esholds, we ob ained a dis ibu ion o he le el o damage caused by each ha es ing me hod s udied (Fig. 7). B uise index and i s de elopmen o e ime Figu e 8 shows he empo al e olu ion o he b uise index om he ime he con olled me hod (H) impac ed he oli e. B uise index alues a di e en imes pos impac showed signi ican di e ences (S uden 's - es , p <0.05; Wilcox- oneManneWhi ney Tes , p <0.05) be ween a ie ies. The median b uise index alues we e i ed o a loga i hmic Table 4 eCIELAB colou space measu ed wi h he colo ime e on ui samples impac ed wi h he con olled ene gy me hod (H) and hose ha es ed wi h he shake comb, b anch shake and bea ing me hods using padding in he in e cep ion. De achmen me hod Va ie y L A b Con olled ene gy (H) (damage zone) ‘Hojiblanca’ 52.9 ±2.9 c 15.1 ±1.7 b 32.4 ±3.2 c ‘Manzanilla’ 52.6 ±3.8 c 11.5 ±2.9 c 30.3 ±3.8 d Con olled ene gy (H) (undamaged zone) ‘Hojiblanca’ 58.6 ±3.0 a 19.2 ±1.1 a 38.6 ±2.3 a ‘Manzanilla’ 62.1 ±2.5 b 18.8 ±3.2 a 40.8 ±3.5 b Manual ‘Hojiblanca’ 59.5 ±3.0 a 18.6 ±2.6 ad 37.8 ±2.8 a ‘Manzanilla’ 62.4 ±2.3 b 18.5 ±2.0 d 39.4 ±3.0 e Mechanical ha es ing (SC, BS, B) ‘Hojiblanca’ 59.0 ±3.1 a 19.0 ±1.3 a 36.5 ±4.6 ‘Manzanilla’ 61.9 ±4.5 b 18.3 ±4.0 d 38.4 ±2.9 a Values shown a e mean ±s anda d de ia ion. Di e en le e indica es signi ican di e ences be ween ows o he same column (K us- kaleWallis, p <0.05; pos -hoc Wilcoxon ank sum es wi h Holm adjus men me hod, p <0.05). *The colo ime e was placed on a andom a ea o he ui ega dless o whe he he a ea was damaged o no , excep o he con olled ene gy me hod, in which i was posi ioned jus abo e he a ea impac ed by he ball. Fig. 4 eColou e olu ion (R) du ing able oli e ipeness h oughou he ha es ing season (median o he alues in RGB space o Hojiblanca y Manzanilla). (Fo in e p e a ion o he e e ences o colo in his igu e legend, he eade is e e ed o he Web e sion o his a icle.) Fig. 5 eB uise index o each ea men o ui de achmen (M: manual by hand, BS: b anch shake , SC: shake comb, B: manual bea ing) and in e cep ion (N: ne s, P: padding) and o each oli e a ie y. The alues shown ep esen median and in e qua ile ange (K uskaleWallis, p <0.05; pos -hoc Wilcoxon ank sum es wi h Holm adjus men me hod, p <0.05). biosys ems enginee ing 215 (2022) 188e202 195 unc ion in ela ion o he ime pos impac . Figu e 9 illus a es he colou di e ences o he b uised spo s be ween he RGB colou channels o e ime. Colou di e ences be ween he wo a ie ies o ui o e he ime we e ound in he ed and g een channel (F iedman Tes p <0.05) bu no in he blue channel. The g ea es changes o e ime occu ed in he g een channel, whe e alues dec eased wi h a g ea e slope in ‘Manzanilla’. Loca ion o he b uising on he su ace o he ui Figu e 10 shows he di e ences in he b uise index be- ween analysing a single image ha pa ially cap u es he su ace o he ui , and he p oposed sys em, which cap u es he en i e ui su ace. The me hods based on b anch shake s and manual ha es ing showed signi ican di e ences be- ween he b uise index de e mined om a single pho o o om he whole pe spec i e in ue magni ude. Con e sely, ha es ing me hods wi h shake comb and bea ing showed no signi ican di e ences. In gene al, when he image o he sp ead ex e nal su ace o he ui is conside ed, he e is a ma ked inc ease in he pe cen age o b uising, a median 140%, conside ing ha 100% is he es ima ed b uising om a single unp ocessed zeni hal pic u e, al hough a high de ia ion exis s in some cases. Fig. 6 eDis ibu ion o b uising alues, bounda y lines o each damage ca ego y shown wi h e ical do ed lines. Fig. 7 eF equency o damage ca ego y o each ea men o ui de achmen (M: manual by hand, BS: b anch shake , SC: shake comb, B: manual bea ing) and in e cep ion (N: ne s, P: padding) and o each oli e a ie y. Di e en le e indica es signi ican di e ences be ween ea men s in he same damage ca ego y (pai wise wo-samples Z- es o p opo ions wi h Holm adjus men me hod, p <0.05). biosys ems enginee ing 215 (2022) 188e202196