Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-02-27T14:30:45Z No. of bitstreams: 1 PGPV16MA207.pdf: 1304865 bytes, checksum: 7b2854584ba3fabd5f5a4cf59285f1f4 (MD5) / Made available in DSpace on 2018-02-27T14:30:45Z (GMT). No. of bitstreams: 1 PGPV16MA207.pdf: 1304865 bytes, checksum: 7b2854584ba3fabd5f5a4cf59285f1f4 (MD5) Previous issue date: 2016-07-28 / Capes / ‘Laetitia’ plums develop internal browning during cold storage. The severity of this disorder is associated with factors such as harvest time, storage time, and oxidative stress. The occurrence of this disorder and rapid ripening of fruits during storage are the main challenges after harvesting plums. Methods such as initial low oxygen stress (ILOS) and heat treatments and ethanol vapor application can be alternatives for controlling internal browning and delaying ripening of fruits. The aim of this study was to evaluate the effect of ILOS, heat treatments and ethanol vapor application on both ripening of fruits and internal browning in ‘Laetitia’ plums cold stored, as well as on the oxidative stress on fruit pulp tissues. The fruits used in the experiments were from commercial orchards located in the municipalities of Urubici, Santa Catarina, 2014/15 and 2015/16 seasons and Vacaria, Rio Grande do Sul, 2014/15. In experiment 1, the following treatments were evaluated: control, ethanol vapor application (0.15%), heat treatment (37ºC/24 h), heat treatment (40ºC/6 h), heat treatment (37°C/24 h) + ethanol vapor application (0.15%), and heat treatment (40ºC/6 h) + ethanol vapor application (0.15%). In experiment 2, the following treatments were evaluated: maintenance of the fruits for 48 h under environmental conditions (20°C ± 5°C/63% ± 2% RH), and five periods of ILOS (1.0 kPa O2) (0, 12, 24, 48, and 72 h) under environmental conditions. Each treatment was performed four times, and an experimental unit comprised 20 fruits. Fruits were stored (1±0.2°C e 92±2% de RH) during 35 days. In experiment 1, heat treatment at both temperatures resulted in a lower incidence of internal browning. The combination of heat treatment at 40°C for 6 h plus ethanol vapor application reduced the ethylene production rate, severity of internal browning, concentration of phenolic compounds, and antioxidant activity. It also maintained greater flesh firmness and POD and SOD activities. In experiment 2, fruits from the treatments with ILOS, at 2014/15, showed lower ethylene production and respiratory rates, less internal browning, as well as greater SOD enzyme activity. Fruits that presented a reddish epidermis color and had a greater fruit compression force and flesh firmness during the 48 and 72 h of ILOS treatment. ILOS treatment for 12 and 24 h led to decreased H2O2 production and greater SOD activity. In fruits from 2015/16, ILOS treatment for 12 h provided greater fruit compression force and flesh firmness and lower ethylene production rate, with less internal browning, lipid peroxidation, and POD and SOD activities / Ameixas ‘Laetitia’ desenvolvem escurecimento de polpa durante o armazenamento refrigerado e a severidade do distúrbio está associada a fatores como ponto de colheita, tempo de armazenamento, estresse oxidativo, entre outros. A ocorrência deste distúrbio e o rápido amadurecimento dos frutos durante o armazenamento caracterizam os principais desafios para a pós-colheita de ameixas. Tratamentos como o estresse inicial por baixo oxigênio (ILOS), tratamento térmico e o etanol podem ser alternativas para o controle do escurecimento de polpa e retardo do amadurecimento dos frutos. O objetivo deste trabalho foi avaliar o efeito do estresse por baixo oxigênio, do tratamento térmico e da aplicação de vapor de etanol sobre o amadurecimento e o escurecimento de polpa em ameixas ‘Laetitia’ armazenadas sob refrigeração, bem como sobre o estresse oxidativo no tecido da polpa dos frutos. Os frutos foram provenientes de pomares comerciais situados nos municípios de Urubici, SC, nas safras 2014/15 e 2015/16, e Vacaria, RS, na safra de 2014/15. No experimento 1, os tratamentos avaliados foram controle, aplicação de vapor de etanol (0,15%), tratamento térmico (37ºC/24 h), tratamento térmico (40ºC/6 h), tratamento térmico (37°C/24 h) + vapor de etanol (0,15%) e tratamento térmico (40ºC/6 h) + vapor de etanol (0,15%). Para o experimento 2, os tratamentos avaliados foram manutenção dos frutos em condições ambiente por 48 horas (20±5ºC/UR de 63±2%) e cinco períodos de ILOS (1,0 kPa O2) (0, 12, 24, 48, 72 horas) em condições ambiente. Cada tratamento foi composto de quatro repetições e unidade experimental constituída de 20 frutos. Os frutos foram armazenados (1±0,2°C e 92±2% de UR) durante 35 dias. No experimento 1 o tratamento térmico, em ambas as temperaturas, resultou em menor incidência de escurecimento de polpa. A combinação de tratamento térmico 40°C por 6 horas mais aplicação de vapor de etanol reduziu a taxa de produção de etileno, a severidade do escurecimento de polpa e a concentração de compostos fenólicos e atividade antioxidante e manteve maior firmeza da polpa e atividade da POD e SOD. No experimento 2 os frutos dos tratamentos com ILOS, safra 2014/15, apresentaram menor taxas de produção de etileno e respiratória e menor incidência de escurecimento da polpa, bem como maior atividade da enzima SOD. Os frutos com cor da epiderme menos vermelha e maior força para compressão do fruto e firmeza de polpa foram observados em ILOS por 48 e 72 horas. Menor quantidade de H2O2, e maior atividade da SOD foram obtidos nos tratamentos com ILOS por 12 e 24 horas. Em frutos da safra 2015/16, o tratamento com ILOS por 12 horas proporcionou maior força para compressão do fruto e firmeza de polpa e menor taxa de produção de etileno, incidência de escurecimento da polpa, peroxidação de lipídios e atividade da POD e SOD

Thesis (MSc Food Sc)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Nectar formulations containing red-fleshed plum pulp and varying amounts of red-fleshed plum skin extract were developed. Red-fleshed plum nectar formulations containing 0, 8, 16, 24, and 32% skin extract were benchmarked against twenty-two commercial beverages containing red, violet and blue fruits. The total soluble solid content, pH, titratable acidity, colour, total polyphenolic, individual polyphenolic, total anthocyanin, and ascorbic acid contents, as well as antioxidant activity (oxygen radical antioxidant capacity (ORAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferric reducing/antioxidant power (FRAP)) of the commercial beverages and plum formulations were determined. The plum nectar formulations had similar or higher total polyphenolic content, antioxidant activity, and colour values than the average for the commercial beverages. The individual polyphenolic compounds analysed in the nectar formulations were cyanidin-3-glucoside, cyanidin-3- rutinoside, quercetin-3-glucoside, quercetin-3-rutinoside, quercetin-3-xyloside, and neochlorogenic acid. Increasing polyphenolic content and antioxidant activity was observed with an increase in skin extract content of the formulations. The sensory attributes of the formulations were plum and plantlike aroma, plum and plantlike flavour, sweetness, acidity, and astringency. Increases in plantlike aroma and flavour, acidity, and astringency in conjunction with decreases in plum aroma, plum flavour, and sweetness extract were observed with an increase in skin extract. Consumer analysis indicated that all formulations were acceptable. The 0 and 16% skin extract formulations were most preferred, while the 32% skin extract formulation was least preferred. A shelf-life study was conducted in two phases. In Phase 1, the 0, 16 and 24% skin extract formulations were stored at 0 and 5°C (analysis time points: before pasteurisation, after pasteurisation (week 0), and after 1, 2, 4, 6, 8, 12, 16, 18, 20, and 24 weeks of storage). Chemical analyses conducted included colour, total polyphenolic, individual polyphenolic compound, and total anthocyanin contents, and antioxidant activity (DPPH• scavenging activity). Results from Phase 1 indicated close associations between the 16 and 24% skin extract formulations, and between these formulations and all chemical attributes. Regression analysis of results indicated significant (P 0.05) decreases in red colour, total anthocyanins, cyanidin-3-glucoside, cyanidin-3- rutinoside, DPPH• scavenging activity, total polyphenolic content, quercetin-3-rutinoside, and quercetin- 3-xyloside for formulations stored at 0°C. The total and red colour, total anthocyanins, cyanidin-3- glucoside, and cyanidin-3-rutinoside in formulations stored at 5°C showed similar results. During Phase 2 of the shelf life study, sensory analysis was conducted on the 0 and 24% skin extract formulations stored at 5°C (preparation time points: 0, 1, 2, and 3 months). Sensory attributes, including plum, plantlike, and raisin flavour, sweetness, acidity, and astringency, were stable during storage. Chemical results from Phase 2 were similar to those of Phase 1. The chemical and sensory stability of formulations after 24 weeks of storage in Phase 1 and Phase 2 indicated that, with the exception of the anthocyanin degradation, the formulations could be beneficial to juice industries. Thus, red-fleshed plum nectars have the potential to compete with high-antioxidant fruit beverages. / AFRIKAANSE OPSOMMING: Nektarformulasies wat rooivleis pruimpulp en varieërende hoeveelhede rooivleis pruimskilekstrak bevat, is ontwikkel en ondersoek. Rooivleis pruimnektarformulasies wat 0, 8, 16, 24, en 32% skilekstrak bevat, is vergelyk met twee-en-twintig kommersiële drankies wat rooi, violet en blou vrugte bevat. Die totale oplosbare vastestof, totale polifenoliese, individuele polifenoliese, totale antosianien- en askorbiensuur inhoude, sowel as die pH, titreerbare suurheid, kleur, antioksidant aktiwiteit (suurstofradikale antioksidantkapasiteit (ORAC), 2,2-difeniel-1-pikrielhidrasiel (DPPH) radikaal blussingsaktiwiteit, en ysterreduserende/antikoksidantkrag (FRAP)) van die kommersiële drankies en pruimnektarformulasies, is bepaal. Die pruimnektarformulasies het soortgelyke of hoër totale polifenoliese inhoud, antioksidantaktiwiteit, en kleurwaardes gehad in vergelyking met die gemiddelde vir die kommersiële drankies. Die individuele polifenoliese verbindings wat in die nektarformulasies geanaliseer is, was sianidien-3-glukosied, sianidien-3-rutinosied, kwersetien-3-glukosied, kwersetien-3-rutinosied, kwersetien-3-xylosied, en neochlorogeniese suur. ‘n Toenames in die kleurwaardes, polifenoliese inhoud, en antioksidantaktiwiteit is waargeneem met ‘n toename in skilekstrak is in die formulasies. Die sensoriese eienskappe van die formulasies was pruim- en plantagtige aroma, pruim- en plantagtige geur, soetheid, suurheid, en frankheid. Toenames in plantagtige aroma en geur, suurheid en frankheid, sowel as ‘n afname in pruimaroma, pruimgeur, en -soetheid, is met ‘n toename in skilekstrak waargeneem. Verbruikersanalise het aangedui dat al die formulasies aanvaarbaar was. Die 0 en 16% skilekstrakformulasies was die mees aanvaarbaarste, terwyl die 32% skilekstrakformulasie die minste aanvaarbaar geag is. ‘n Rakleeftydstudie is in twee fases gedoen. In Fase 1 is die 0, 16, en 24% skilekstrakformulasies by 0 en 5°C gestoor (analiseringstydpunte: voor pasturisasie, na pasturisasie (week 0), en na 1, 2, 4, 6, 8, 12, 16, 18, 20, en 24 weke van berging). Chemiese analise wat gedoen is, sluit totale polifenoliese, individuele polifenoliese verbinding, en totale antosianien inhoude, sowel as kleur en antioksidantaktiwiteit (DPPH• blussingsaktiwiteit) in. Resultate van Fase 1 het ‘n nou verband tussen die 16 en 24% skilekstrakformulasies, sowel as tussen hierdie formulasies en hul chemiese kenmerke aangedui. Regressie-analise van resultate het betekenisvolle (P 0.05) afnames geïllustreer in rooi kleurwaardes, DPPH• blussingsaktiwiteit, sowel as totale antosianiene, sianidien-3-glukosied, sianidien-3-rutinosied, totale polifenoliese, kwersetien-3-rutinosied, en kwersetien-3-xylosied inhoude van die formulasies wat by 0°C gestoor is. Die totale kleur-, rooi kleurwaardes, sowel as totale antosianien, sianidien-3-glukosied, en sianidien-3-rutinosied in die formulasies wat by 5°C gestoor is, het soortgelyke resultate gegee. Gedurend Fase 2 van die rakleeftydstudie is sensoriese analise op die 0 en 24% skilekstrakformulasies wat by 5°C gestoor is, gedoen (voorbereidingstydpunte: 0, 1, 2, en 3 maande). Sensoriese eienskappe, insluitend pruim-, plantagtige-, en rosyntjiesmake, soetheid, suurheid, en frankheid, was stabiel gedurende berging. Chemiese resultate van Fase 2 was soortgelyk aan dié van Fase 1. Die chemiese en sensoriese stabiliteit van die formulasies na 24 weke van opberging in Fase 1 en Fase 2 nieteenstaande antosianienafname, het aangedui dat die formulasies voordelig kan wees vir die vrugtedrankiebedryf. Dus het rooivleis pruimnektars die vermoeë om met hoë antioksidant vrugtedrankies mee te ding.