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Andrea C Galvis‐Snchez Susana C Fonseca Alcina MMB Morais F Xavier Malcata 《Journal of the science of food and agriculture》2004,84(13):1646-1656
Pears (cv Rocha) kept under controlled atmospheres (CA) and air were evaluated after long‐term storage in terms of sensory attributes and physicochemical parameters, namely colour, firmness, polyphenoloxidase (PPO) activity and concentration of hydroxycinnamic compounds. The CA conditions were all combinations of 2 and 4% (v/v) O2 with 0.5 and 1.5% (v/v) CO2. Storage under CA conditions produced a beneficial effect on ‘Rocha’ pears in maintaining their quality and, consequently, in extending their shelf life and acceptability. Clear differences in sensorial attributes, colour parameters and PPO activity were found between CA‐ and air‐stored pears. The effect provided by the CA conditions persisted throughout the time of exposure to the open air. The 2% O2 concentration produced a more beneficial effect than its 4% counterpart on the sensorial and physical characteristics of the pears. The former concentration of O2 prevented yellowing and allowed regular softening, hence keeping a high flavour quality. No clear effects could be associated with CO2 levels. Empirical models were developed that describe the effects of O2 and CO2 concentrations, as well as time at room temperature on physicochemical parameters pertaining to ‘Rocha’ pears. Copyright © 2004 Society of Chemical Industry 相似文献
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A.C. Galvis-Sánchez S.C. Fonseca A.M.M.B. Morais F.X. Malcata 《Journal of food science》2003,68(1):318-327
ABSTRACT: The effects of several processing factors (storage time, time in the open air at room temperature, and overhead concentrations of O2 and CO2) on color, firmness, polyphenol oxidase (PPO) activity, and sensory attributes of pears (cv. Rocha) grown in 2 locations were studied using a multiple linear regression model. Backward elimination (F ≥ 0.005) was used to assess the significant factors. Extended storage time, long‐time exposure at room temperature, and high O2 concentration played major roles on color changes assessed instrumentally and further confirmed by a sensory panel. Firmness was strongly affected by storage time and by time in the open air at room temperature. Finally, PPO activity was dependent on the growing location. 相似文献
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Ana B Cabezas‐Serrano Maria L Amodio Rosaria Cornacchia Raffaella Rinaldi Giancarlo Colelli 《Journal of the science of food and agriculture》2009,89(15):2588-2594
BACKGROUND: Artichoke is a rich source of bioactive compounds, mainly phenols, in the Mediterranean diet, but its consumption is limited by the complexity of time‐consuming trimming operations. Fresh‐cut processing would therefore add convenience to its consumption, even though the severity of post‐cutting browning of artichoke pieces is still a major problem. Since susceptibility to browning may vary widely among genotypes, the choice of the cultivar is a very critical step in the fresh‐cut process. In this study, five different Italian cultivars (C3, Catanese, Tema, Violetto Foggiano and Violetto Sardo) were screened for their initial quality and composition, and their post‐cutting performance during storage at 5 °C and 20 °C. RESULTS: C3 showed the highest phenol content (3.4 g GA kg?1) and antioxidant activity (24.5 mmol L?1 kg?1), but the worst quality in terms of appearance and colour changes, also due to its high PPO activity (62.2 U g?1). Catanese showed the highest vitamin C content (117.7 mg kg?1), the lowest phenol content (1.8 g GA kg?1), and the best post‐cutting quality. Tema, Violetto Foggiano and Violetto Sardo showed an intermediate phenol content, the latter showing the lowest appearance score after C3. CONCLUSION: These results confirmed the role of phenols in browning processes of fresh‐cut artichokes, giving the first available information on artichoke cultivar suitability to be processed as a fresh‐cut product. Copyright © 2009 Society of Chemical Industry 相似文献
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超高压处理对鲜榨桃汁多酚氧化酶(PPO)活力影响的研究 总被引：1，自引：0，他引：1
桃汁中的PPO是耐高压的酶,200～500MPa的压力处理使果汁中PPO活力逐渐降低，但降低幅度不大，400MPa的压力对PPO有激活作用。高于600MPa的压力，失活PPO的效果开始显著。VC在500MPa以下对果汁中PPO有激活作用，在600MPa以上或热处理结合高压时有钝化PPO的作用。随着保压时间的延长和温度的升高，桃汁中多酚氧化酶相对活性逐渐降低。500MPa60℃或750MPa50℃以上的处理强度可使鲜榨桃汁中的PPO失去61％以上的活力。 相似文献
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香辛料调味品褐变机理的分析研究 总被引：1，自引：0，他引：1
研究了香辛料调味品在贮藏期间褐变度(DB)及有关成分的变化,分析确定了引起褐变的原因及引起酶促褐变的主要底物,并探讨了香辛料调味品中多酚氧化酶(PPO)的部分酶学特性。实验结果表明,香辛料调味品在贮藏过程中PPO活性和褐变度的变化呈显著负相关性(r=-0.9535),即褐变主要是由酚类发生的酶促氧化所致,香辛料调味品PPO的最适反应pH为6.8,PPO与不同底物结合力的大小依次为焦性没食子酸>酪氨酸>儿茶酚>苯酚>愈创木酚;化学抑制剂CA(柠檬酸)、Na2SO3、Vc、Zn(Ac)2、EDTA-2Na、L-cys和植酸对PPO活性均有不同的抑制作用,尤以Na2SO3、L-cys、CA的抑制作用明显。 相似文献
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Cefola M Pace B Buttaro D Santamaria P Serio F 《Journal of the science of food and agriculture》2011,91(12):2153-2159
BACKGROUND: Soilless growth systems, developed mainly for vegetables and ornamental crops, have also been used recently as an alternative to soil culture for table grape in order to achieve optimal production performance. In this study, sensory, physical and chemical parameters were analysed in table grapes obtained from soil and soilless growth systems at harvest and during storage in air or modified atmosphere. RESULTS: At harvest, soilless‐grown berries were 30% firmer than those grown in soil. Moreover, they showed 60% higher antioxidant activity and total phenol content than soil‐grown fruits. Modified atmosphere storage resulted in a better quality of table grapes compared with those stored in air. Furthermore, soilless growth was more suitable than soil growth for preserving visual quality and controlling rachis browning and weight loss. CONCLUSION: Since the soilless system produces berries that are cleaner and of higher quality than those grown in soil, the implementation of soilless growth for the production of health‐promoting and convenience fruits is suggested. Copyright © 2011 Society of Chemical Industry 相似文献
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Su M Chen K Ye Z Zhang B Guo J Xu C Sun C Zhang J Li X Wu A Xi W 《Journal of the science of food and agriculture》2012,92(7):1448-1454
BACKGROUND: The aim of this study was to determine physical changes in nectarine and distinctive physiological characteristics related to red and green peel under stresses occurring during fruit maturation, information on which is currently not available. RESULTS: Fruit firmness increased from 4 to 6 weeks after blooming (WAB) then decreased from 6 WAB until ripening. Anthocyanins in red and green peel during nectarine maturation were identified by high‐performance liquid chromatography as cyanidin 3‐glucoside together and, at a much lower level, cyanidin 3‐rutinoside. Cyanidins in red and green peel decreased from 4 to 8 WAB then increased from 8 to 12 WAB. Anthocyanin contents were positively correlated with PAL, POD, A*, MDA and O$_{2}^{bullet-}$ values and inversely correlated with L* and B* values. Red and green peel during maturation could be separated by hierarchical cluster analysis of the tested data. CONCLUSION: This study has provided an overview of red and green peel characteristics during nectarine (cv. Hu018) maturation. Values of A*, anthocyanins, O$_{2}^{bullet-}$ , MDA, PAL, PPO and POD in red peel were higher than those in green peel, while values of L*, B* and chroma in red peel were lower than those in green peel throughout fruit maturation. Copyright © 2011 Society of Chemical Industry 相似文献
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Shampa Sarkar;Sumaia Akhter;Joysree Roy;Md. Abdul Wazed;Raihan Abedin;Suvrow Neogie;Khairul Bashar Mishat;Md. Sazzat Hossain Sarker; 《Food Science & Nutrition》2024,12(9):6612-6626
The rising demand for freshly cut agricultural produce like bananas, apples, pears, potatoes, and roots due to health concerns and modern lifestyles has heightened awareness of their susceptibility to browning, which diminishes their appeal and contributes to food waste. The present study explored the efficacy of natural anti-browning agents in prolonging the quality and shelf-life of freshly cut green banana slices. The bananas underwent treatment with normal water (NW), lemon juice (LJ), and coconut water (CW), and the changes in physicochemical properties, such as browning intensity, color, firmness, total soluble solid (TSS), total phenolic content (TPC), total flavonoid content (TFC), and also microbial attributes, were evaluated during their storage at 4 ± 1°C for 12 days. The results demonstrated significant enhancements in treated samples compared to untreated ones. While normal water and lemon juice-treated banana slices exhibited visual browning during storage, coconut water immersion proved superior in maintaining visual appeal, whiteness, and lightness while delaying yellowing and browning. Coconut water-treated samples also displayed firmer texture (0.75 kg), lower TSS (5.67 °Brix), and reduced weight loss (9.14%) after 12 days, in contrast to samples subjected to lemon juice and normal water treatments which showed lesser texture (0.68 kg, 0.58 kg), higher TSS (5.87 °Brix, 6.10 °Brix), and greater weight loss (11.76%, 16.09%), respectively. Furthermore, coconut water-treated samples retained higher levels of total phenols (392.67 mg GAE (gallic acid equivalent)/100 g FW (fresh weight), total flavonoids (55.67 mg QE (quercetin equivalent)/100 g FW), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity (38.68%). Coconut water treatment also significantly suppressed polyphenol oxidase (PPO) activity (14 U/g) compared to lemon juice (16 U/g) and normal water (26 U/g) treatments, and untreated samples (133 U/g) after 12 days. Additionally, microbial load remained within acceptable limits for all samples, with coconut water-treated samples showing the lowest values. Thus, coconut water is a promising natural solution for inhibiting browning and preserving the quality of fresh-cut green banana slices during storage. 相似文献
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Eleven apple cultivars were subjected to heat treatments at various times and temperatures. Susceptibility to browning during heat treatment and after heat treatment was evaluated. Changes in firmness, respiration rate, soluble solids and acidity of slices prepared with heat treated apples were measured. Incidence of browning was dependent upon cultivar and heating temperature; Liberty, Monroe, RI Greening and Rome were very susceptive, while McIntosh, NY 674 and Empire were less susceptive. Golden Delicious and Delicious showed relative strong tolerance to heat. Apples that received heat treatment at 45°C produced slices with less browning and firmer texture compared to non-treated apples. The positive effect of heat treatment might help produce high quality minimum processed fruits. 相似文献
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鲜切山药酶促褐变机理的研究 总被引：30，自引：11，他引：19
本文研究了鲜切山药在贮藏期间BD及有关成分的变化,分析测定了鲜切山药多酚氧化酶(PP0)的酶学特性,利用薄层层析、HPLC及紫外吸收光谱鉴定引起酶促褐变的主要底物。结果表明：鲜切山药在贮藏过程中PP0活性和游离酚含量呈同步性变化且达显著相关(r＝0．9964),表明褐变主要是酚类发生的酶促氧化。鲜切山药PP0的最适反应温度为45℃,最适反应pH为5．0和6．8;PP0与不同底物结合能力的强弱依次为绿原酸＞儿茶酚＞酪氨酸＞焦性没食子酸＞愈创木酚＞苯酚;化学抑制剂NaHS03、EDTA—2Na、Zn(Ac)2、CA、VC、L—Cys、NaCl均有不同程度的抑制作用,尤以NaHS03的抑制作用明显;引起酶促褐变的主要底物是绿原酸。 相似文献
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Different pretreatments (bruising, hot and cold water) were used to study their effect on fermentation as measured by the quality parameters of honeybush tea (Cyclopia maculata). Bruising and pretreatment with water (hot and cold) were investigated as means to increase the fermentation rate and to improve product quality. The development of the desired dark-brown colour and honey-like flavour during fermentation was faster in hot and cold water treated material and gave a more uniform coloured product than with the bruising pretreatment. Liquor characteristics also improved with water pretreatment. A red–brown extract, compared with the light yellow–brown of untreated samples, was obtained with the water pretreatment. Hot water pretreatment inactivated the enzymes polyphenol oxidase (PPO) and peroxidase (POD), but did not terminate or impair fermentation. The inactivation of the enzymes, together with high temperature (>60°C) fermentation, indicated a chemical oxidation process rather than an enzymatic reaction in honeybush tea fermentation. © 1998 SCI. 相似文献
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Supradip Saha Nirmal K Hedau Vinay Mahajan Gyanendra Singh Hari S Gupta Anita Gahalain 《Journal of the science of food and agriculture》2010,90(2):239-244
BACKGROUND: Screening of natural biodiversity for their better quality attributes is of prime importance for quality breeding programmes. A set of 53 tomato genotypes was measured for their textural [skin firmness, pericarp thickness, total soluble solids (TSS)], nutritional [phosphorus (P), potassium (K), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn) and titrable acidity (TA)] and functional (β‐carotene, lycopene and ascorbic acid) quality attributes. RESULT: Three sets of data (textural, nutritional and functional attributes) were obtained and analysed for their mutual relationships. Wide variations were observed in most of the measurements, e.g. skin firmness (coefficient of variability (CV) 269‐612 g), pericarp thickness (CV 1.4–4.9 mm), potassium (CV 229–371 mg 100 g?1), iron (CV 611–1772 mg 100 g?1), ascorbic acid (CV 12–86 mg 100 g?1), suggesting that there are considerable levels of genetic diversity. Significant correlations (P < 0.05, 0.01) were also detected among different attributes of tomato genotypes, such as phosphorus and zinc with a correlation coefficient of 0.74, ascorbic acid and copper of 0.57, pericarp thickness and lycopene of ? 0.52. However, there were no correlations between textural and nutritional attributes. Five factors were computed by principal component analysis that explained 66% of the variation in the attributes, among which all micronutrients other than iron, TSS, firmness and β‐carotene were most important. Functional attributes except β‐carotene played a less important role in explaining total variation. CONCLUSION: This knowledge could aid in the efficient conservation of important parts of the agricultural biodiversity of India. These results are also potentially useful for tomato breeders working on the development of new varieties. Copyright © 2009 Society of Chemical Industry 相似文献
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