Comparison of Quality Characteristics of Selected Yellow-and White-fleshed Peach Cultivars

Physical, chemical and sensory characteristics and volatile constituents of five yellow-and six white-fleshed peach cultivars were compared. The soluble solids/titratable acidity ratios were significantly higher and the Minolta “b” values were significantly lower for white-fleshed than for yellow-fleshed cultivars. Shelf life of white-fleshed fruit equalled that of yellow-fleshed fruit. Amounts of five compounds that contribute significantly to typical peach aroma were significantly higher in white-fleshed than in yellow-fleshed peaches. Generally, flesh color showed little influence on hedonic scores, peach impact and sweet/sour balance.     

Respiration and Storage Quality of Fresh-Cut Apple Slices Immersed in Sugar Syrup and Orange Juice

Storing fresh-cut apple slices in suitable fruit juice or sugar syrup is a general practice. However, application of this approach is mainly based on empirical knowledge, while systematic and comprehensive analyses of the relevant effects of this storage technique on keeping quality-related physiological properties of fresh-cut products is still missing. Hence, the aim of this study was to evaluate the impacts of complete immersion of fresh-cut apples in sugar syrup and fruit juice solution on respiratory behaviour and other relevant quality attributes (colour, tissue strength, and soluble solid and acidity). Sugar syrup and pure orange juice showed a high potential to store and protect fresh-cut apples. Results showed that only pure orange juice positively affected the produce quality by preventing browning effects. In addition, sugar syrup of 13.4–20% most effectively prevented browning of apple slices and guaranteed high product quality retention during storage. The application of different liquid media provides a practical means to prevent browning and maintain product quality.     

氧化白藜芦醇对鲜切苹果及果汁褐变的影响

为研究氧化白藜芦醇(oxyresveratrol,OXY)对苹果褐变的抑制作用,采用不同浓度的OXY对鲜切苹果、苹果汁进行处理,探讨在不同储藏阶段切片色度和果汁褐变度变化情况及OXY对苹果汁内多酚氧化酶(polyphenol oxidase,PPO)和过氧化物酶(peroxidase,POD)活性的影响。结果表明:OXY可改善苹果切片的感官品质,显著延缓切片L*值的降低(P<0.05),抑制a*、b*、ΔE值的升高(P<0.05)。同时,OXY还能显著降低苹果汁褐变度(P<0.05),显著抑制苹果汁内PPO和POD活性(P<0.05)。综上,OXY能有效抑制鲜切苹果片及苹果汁褐变,其作用机制可能是通过抑制苹果内PPO和POD活性实现。     

鲜切苹果品质保持研究

文研究了不同褐变抑制剂对鲜切苹果PPO活性、褐变度、感官品质的影响。试验结果表明:单一的1.5%L-半胱氨酸、1.0%D-异VC钠、1.0%谷胱甘肽处理均能较好地抑制鲜切苹果褐变。采用0.10%D-异VC钠+0.12%谷胱甘肽+0.13%L-半胱氨酸,浸泡2min的复合处理,可使鲜切苹果的PPO活性、褐变度、感官品质在14d内保持较优水平。     

鲜切苹果抗褐变研究

研究了不同褐变抑制剂对鲜切苹果PPO(多酚氧化酶)活性、褐变度、感官品质的影响。试验结果表明单一的1.5%L-半胱氨酸、1.0%D-异VC钠、1.0?TA-2Na处理均能较好地抑制鲜切苹果褐变。采用0.10%D-异VC钠 0.12?TA-2Na 0.13%L-半胱氨酸,浸泡2min的复合处理,可使鲜切苹果的PPO活性、褐变度、感官品质在14d内保持较优水平。     

Physicochemical changes in fresh-cut wax apple (Syzygium samarangenese [Blume] Merrill & L.M. Perry) during storage

Physicochemical changes, such as peel and flesh colours, total anthocyanin content, browning index, firmness, total soluble solid (TSS), titratable acidity (TA), sugar acid ratio (TSS/TA), antioxidant capacity, total phenolic content and ascorbic acid content, in fresh-cut Taaptimjan wax apple fruit stored at 4 ± 2 °C and 12 ± 2 °C for 7 days were investigated. The skin of fresh-cut fruit stored at 4 ± 2 °C showed higher a^∗ value, chroma and total anthocyanin content and lower hue angle than those stored at 12 ± 2 °C. Lightness (L^∗ value) and whiteness index of the fresh-cut fruit flesh stored at 12 ± 2 °C showed significantly lower than those stored at 4 ± 2 °C which related to an significant increase in browning index. Firmness, total soluble solid, titratable acidity and sugar acid ratio did not significant changes during storage. Antioxidant capacity and total phenolic content increased throughout storage. Ascorbic acid content of the fresh-cut fruit stored at 4 ± 2 °C remained constant throughout storage whilst ascorbic content at 12 ± 2 °C decreased and was lower than that at 4 ± 2 °C. At 4 ± 2 °C antioxidant capacity and ascorbic acid content were higher than that stored at 12 ± 2 °C whilst there was no significant difference in total phenolic content. In conclusion, the reduction of whiteness index and the increase in browning index of fresh-cut wax apple flesh were the key factors affecting its quality and storage at 4 ± 2 °C could reduce the change in the flesh colour and maintained the peel colour and nutritional values of fresh-cut wax apple fruit during storage.     

Quality Measurement of Intact and Fresh-cut Slices of Fuji, Granny Smith, Pink Lady, and GoldRush Apples

ABSTRACT: Development of fresh-cut apple products requires consideration of cultivars that store well as both intact and fresh-cut fruit. We compared the instrumental and sensory quality of 2 apple cultivars, Granny Smith and Fuji, that are used for fresh cutting with 2 new cultivars, Pink Lady and GoldRush, which were considered to have quality characteristics suitable for fresh cutting. Firmness, titratable acidity (TA), soluble solids content (SSC), and aromatic volatile concentration were measured in intact fruit of the 4 cultivars during 12 mo storage in air at 0 °C and during 3 wk storage at 5 °C as fresh-cut slices. After 1 wk storage as fresh-cut slices, sensory evaluations for acceptability of flesh and peel appearance, flavor, texture, and overall eating quality were performed. During storage, GoldRush apples maintained > 80 N firmness, approximately 17% SSC, > 0.5% TA, and had high aromatic volatile production, that is, maintained quality better than the other cultivars. The quality and shelf stability of GoldRush slices were also as good as or better than slices from the other cultivars, whereas Granny Smith slices generally rated lower than the other cultivars. The acceptability of flavor, texture, and overall eating quality of GoldRush slices was as good as that for Pink Lady and Fuji. The quality of GoldRush apples can be maintained throughout the year in refrigerated air storage and still remain suitable for fresh-cut processing. The results indicate that GoldRush and Pink Lady are 2 promising new, high-quality apple cultivars for fresh cutting. Keywords: fresh-cut fruit, Malus × domestica , postharvest quality, respiration rate, shelf life     

基于主成分分析与聚类分析的中、早熟桃品种制汁品质评价

为了探讨桃果实品种和成熟度对出汁率和桃汁品质的影响,选择适宜的制汁品种,对15?个中、早熟桃品种3?个成熟度（I、II、III）果实的出汁率以及桃汁的糖、酸组分及质量浓度、总酚质量浓度、褐变度等15?个指标进行测定,运用描述性分析、主成分分析和聚类分析对桃汁品质进行综合评价。结果表明：不同品种和成熟度桃果实制备的桃汁品质差异较大。主成分分析一共提取了5?个主成分,反映了原变量80.333%的信息。第一、第二主成分主要综合了糖、酸质量浓度的信息;第三、第四主成分主要综合了出汁率和色泽的信息;第五主成分主要综合了总酚质量浓度和褐变度的信息。在第一主成分和第二主成分得分图上,综合得分排名较高和较低的品种可以明显区分;通过第一主成分和第三主成分得分图可以将3?个成熟度很好地区分。聚类分析将45?个样品聚为6?类,与主成分分析结果基本一致。在所有样品中,综合得分排名第一的是‘中油桃12号’-III,排名最后的是‘中桃1号’-I。整体而言,黄肉品种桃汁的综合品质较好,中熟品种优于早熟品种,成熟度高的原料制得的桃汁品质较好。     

基于品质指标的苹果浊汁品种与产地差异性分析

以来自7?个不同主产区的21?个主栽品种,共41?份苹果鲜果为研究对象,对每个品种鲜榨浊汁的出汁率、浊度、果汁颜色、褐变度、透光率、可溶性固形物、可滴定酸、总酚、糖、有机酸、VC、矿物质、抗氧化性等品质指标进行测定。运用描述性分析、逐步线性判别分析进行数据处理。结果表明：不同品种或不同产地的苹果浊汁,品质差异较大。总体来看,a*值、原始浊度、褐变度、可滴定酸、葡萄糖、蔗糖、苹果酸等指标的变幅均较大,分别为94.07%、70.41%、42.86%、35.26%、42.02%、42.40%、37.69%。对于不同品种的苹果浊汁,由于褐变度、总酚、抗氧化性等色泽品质指标以及糖、酸等营养品质指标间具有较大差异,其分布呈现分散状态。其中新红星品种的褐变度、总酚含量、DPPH自由基清除率等品质指标普遍居高,色泽品质差异最显著。富士品种大部分样品的果糖、葡萄糖、蔗糖、苹果酸等指标含量较高,具有较好的营养品质。然而对于不同产地间的样品,其浊度、可滴定酸、可溶性固形物等加工品质指标具有较大差异,样品分布较为分散。河北省样品的出汁率、原始浊度、可滴定酸等指标普遍较低,加工品质较差。来自山东省不同品种苹果浊汁的样品以及来自不同产地富士苹果浊汁的样品间均具有较大差异,并且分别获得了77.8%和72.7%的判别准确率。以上结果表明,不同产地、不同品种苹果原料制得的苹果浊汁存在较大差异,通过对其品质指标进行差异性分析,可为上游育种与种植产业结构调整提供数据基础;通过判别模型的建立实现品种与产地的识别与预测,可以指导企业对苹果原料进行制汁专用化筛选。     

Dual effectiveness of sodium chlorite for enzymatic browning inhibition and microbial inactivation on fresh-cut apples

The dual effectiveness of sodium chlorite for browning inhibition and microbial inactivation on fresh-cut apples was investigated and compared to other anti-browning and antimicrobial agents. Results indicate that sodium chlorite significantly (P < 0.001) inhibited the browning reaction of fresh-cut Red Delicious apples stored at 5 °C for 14 days. This treatment also significantly reduced polyphenol oxidase activities. Treatments with acidified sodium chlorite, calcium chloride, or calcium ascorbate exhibited strong inhibition on apple browning during the early storage, these treatment effects diminished after 7 days in storage. Combining calcium chloride with sodium chlorite further significantly (P < 0.001) improved the firmness of apple slices, and browning inhibition during storage. Additionally, treatments with acidified sodium chlorite, sodium chlorite, or the combination of sodium chlorite and calcium chloride significantly (P < 0.001) reduced Escherichia coli populations on fresh-cut apples by 3.0, 3.6, and 3.9 log cfu g⁻¹ over the water control. The dual effectiveness of sodium chlorite to inhibit enzymatic browning and inactivate E. coli may allow this compound to achieve a prominent role in improving the quality and safety of products in the fresh-cut apple and other food industries.     

半胱氨酸控制鲜切苹果褐变的生理机制

为研究半胱氨酸对鲜切苹果褐变控制的生理机制,以鲜切苹果为研究对象,采用0.5 g/L的半胱氨酸溶液处 理1 min,分析贮藏过程中鲜切苹果褐变指数（browning index,BI）、多酚氧化酶（polyphenol oxidase,PPO）和 抗氧化酶活力、抗氧化物质和丙二醛（malondialdehyde,MDA）质量摩尔浓度及抗氧化能力的变化。结果表明, 与蒸馏水处理相比,半胱氨酸处理能够显著抑制鲜切苹果的褐变,在贮藏初期半胱氨酸处理降低了鲜切苹果的PPO 活力,同时在贮藏过程中不同程度提高了鲜切苹果的抗氧化酶活力以及抗氧化能力,减缓了抗氧化物质在贮藏过程 中的损失,并且抑制了MDA的积累。相关性分析显示,鲜切苹果的BI值与抗坏血酸含量、过氧化氢酶活力以及抗 氧化能力呈极显著负相关（P＜0.01）,与MDA质量摩尔浓度呈极显著正相关（P＜0.01）。因此,半胱氨酸可能是 一方面通过抑制鲜切苹果的PPO活力,另一方面通过提高其抗氧化能力,延缓贮藏过程中的组织褐变。     

Polyphenoloxidase activity and total phenolic content as related to browning of minimally processed ‘Jonagored’ apple

Phenolic content, polyphenoloxidase (PPO) activity and browning have been reported by different authors to vary in different ways, depending on cultivar, picking maturity, storage conditions, etc. Numerous authors have attempted to correlate browning results with the phenolic content and/or enzymatic activity of apples, but data published in the literature are divergent as to which of the two factors, ie the enzyme or the substrate, plays the decisive role in the overall phenomenon of enzymatic browning. The aim of this work was to follow the PPO activity and phenolic content of minimally processed apple (cv ‘Jonagored’) during cold storage and to establish a potential relationship with enzymatic browning. Increasing storage time of minimally processed apple seemed to result in an increase in PPO activity. No changes (P > 0.05) in total phenolic content were observed during storage. Colour degradation of apple cubes, as indicated by changes in colour parameters, was found to be highly correlated with PPO activity. Browning of ‘Jonagored’ apple cubes during storage was found to be moderately correlated with PPO activity. No correlation was found between the browning index and the total phenolic content. © 2001 Society of Chemical Industry     

Control of browning and microbial growth on fresh-cut apples by sequential treatment of sanitizers and calcium ascorbate

ABSTRACT:  This study investigated the efficacy of different sanitizers, including acidic electrolyzed water (AEW), peroxyacetic acid (POAA), and chlorine, on the inactivation of Escherichia coli O157:H7 on fresh-cut apples. The effects of the sanitizers and sequential treatments of AEW or POAA followed by calcium ascorbate (CaA) on browning inhibition and organoleptic qualities of fresh-cut apples stored under different package atmospheres at 4 °C were also evaluated. Changes in package atmosphere composition, product color, firmness, total aerobic bacterial counts, yeast and mold counts, and sensory qualities were examined at 0, 4, 8, 11, and 21 d. Among all sanitizer treatments, POAA and AEW achieved the highest reduction on E. coli O157:H7 populations. The sequential treatment of AEW followed by CaA (AEW-CaA) achieved the best overall dual control of browning and bacterial growth on fresh-cut apple wedges. Package atmospheres changed significantly over time and among package materials. Packages prepared with films having an oxygen transmission rate (OTR) of 158 had significantly lower O₂ and higher CO₂ partial pressures than those prepared with 225 OTR films and the Ziploc™ bags. The effect of package atmospheres on the browning of apples is more pronounced on AEW, POAA, and POAA-CaA-treated apple wedges than on AEW-CaA-treated samples.     

不同品种苹果果实主要酚类物质含量的研究

用高效液相色谱仪测定了不同品种苹果果实绿原酸、儿茶素、表儿茶素、根皮素和槲皮素等主要酚类物质的含量。结果表明,不同品种苹果果肉酚类物质总量以富士和新红星最高,金冠最低。富士苹果果肉酚类物质以绿原酸为主,新红星和王林苹果果肉以表儿茶素为主。不同品种苹果果皮酚类物质总量以新红星最高,各品种苹果果皮酚类物质总量均高于果肉。果皮中酚类物质以黄烷-3-醇类为主。     

Changes in Apple Polyphenoloxidase and Polyphenol Concentrations in Relation to Degree of Browning

Polyphenoloxidase (PPO) activity and polyphenol concentrations decreased during maturation and remained relatively constant during cold storage. However, there was no set pattern of changes in degree of browning during maturation and cold storage. Not all cultivars showed the same relationship between degree of browning and enzyme activity. In some cultivars (Classic Delicious, RI Greening, McIntosh and Cortland), PPO activity was directly related to degree of browning while in others (Empire, Rome and Golden Delicious), degree of browning was related more to phenolic concentration. High performance liquid chromatography analysis of the phenolics in apples showed that the types of phenolic compounds in all cultivars were similar and that no one particular compound could account for the differences observed in browning.     

Effect of alternating magnetic field on the quality of fresh-cut apples in cold storage

This study evaluated the inhibitory effect of alternating magnetic field (MF) on enzymatic browning, physicochemical properties and microbial proliferation of fresh-cut apples during cold storage. The results showed that after 9-day storage, the browning index of apple slices increased by 174.07% in the conventional refrigerated group but by only 132.32% in the alternating MF group, the total number of colonies in the alternating MF group was 1.32 log CFU g⁻¹, less than that in the conventional refrigerated samples. The soluble solids and firmness of the MF group were 16.47% and 28.79% higher than those of the control group. The alternating MF significantly inhibited the activities of polyphenol oxidase (PPO) and peroxidase (POD) and exerted a significant effect on the tertiary structure of enzymes. Except for maintaining the good sensory quality, the MF also suppressed the growth of microorganisms in fresh-cut apples and extended their shelf life by at least 2 days.     

Phenolic compounds in some apple (Malus domestica Borkh) cultivars of organic and integrated production

Eleven organically grown apple cultivars and 11 apple cultivars of integrated production from Austria and Slovenia were analyzed by HPLC for the content of phenolic compounds in peel and pulp. We identified chlorogenic acid, p‐coumaric acid, procyanidin B3, protocatechuic acid, (?)‐epicatechin, phloridzin, rutin and quercetin‐3‐rhamnoside in apple peel. In apple pulp, (+)‐catechin was also identified in all the cultivars. Some other phenols (procyanidin B3, rutin and quercetin‐3‐rhamnoside) could not be identified or were not properly separated. With regard to the phenolic content in the apple peel, there were no differences between organically grown apple cultivars and apple cultivars of integrated production. Organically grown apples, however, exhibited a higher content of phenolic substances in the apple pulp compared with the apple cultivars of integrated production. This may be due either to the different genotype source or to the growing technology. Higher concentrations of phenolic compounds in organically grown cultivars could be a result of plant response to stress. The apple peel contained higher concentrations of identified phenols than the pulp. The apple peel represents up to 10% of the whole fruit; therefore the phenolsic compounds in the pulp are of greater importance to the consumer than the phenolic compounds in the peel. Copyright © 2005 Society of Chemical Industry     

物理方法在鲜切苹果保鲜中的应用研究进展

鲜切苹果具有新鲜、方便等优点,深受消费者的青睐。但鲜切时造成的机械损伤会破坏苹果天然的组织结 构,极易出现褐变、果实软化、腐烂等问题。传统的化学保鲜方法已不能满足消费者对食品安全高质量的要求,而 物理保鲜技术因其处理条件易于控制、保鲜效果好、安全性高的优势,在果蔬贮藏保鲜中应用广泛。本文综述了光 电方法、高压技术、气调贮藏技术、温度调控和其他物理技术在提高鲜切苹果贮藏品质方面的研究进展,分析了这 些技术通过钝化酶活性、抑制酶促褐变、杀灭微生物的方式以保持和提高鲜切苹果感官品质方面的可能机理。随着 这些技术的应用和发展,鲜切苹果的贮藏保鲜品质将得到保障。     

紫外线照射与柠檬酸处理对鲜切苹果的保鲜作用

目的研究柠檬酸、紫外线照射、柠檬酸和紫外线照射联合处理对鲜切苹果生理生化的影响。方法以富士苹果为实验材料,分成4组,分别是0.5%柠檬酸(CA)溶液中浸泡5 min、紫外照射(UV)5 min/面、0.5%柠檬酸溶液中浸泡5 min+紫外照射(CA+UV)5 min/面、不处理的对照组(KB)。分别于0、1、3、5、7、10、13、15 d测定鲜切苹果的色差、多酚氧化酶(PPO)、过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)活性。结果富士苹果经过切分后,褐变严重。PPO、POD活性升高,PAL活性变化曲折,总体呈上升趋势。柠檬酸、紫外、柠檬酸和紫外联合处理的3三种处理方式都可以抑制鲜切苹果的褐变,降低PPO、POD、PAL的活性。在4种处理方法比较中,柠檬酸和紫外联合处理的效果比较好。结论柠檬酸和紫外联合处理是鲜切苹果的理想的保鲜方法。     

Effect of Tapioca Starch/Decolorized Hsian-tsao Leaf Gum-Based Active Coatings on the Qualities of Fresh-Cut Apples

The effect of tapioca starch/decolorized hsian-tsao leaf gum (dHG)-based edible coatings with various food additives (including ascorbic acid, calcium chloride, and cinnamon oil) on the qualities and shelf life of fresh-cut “Fuji” apple pieces was investigated during the refrigerated storage. The initial respiration rate, headspace gas composition, color, texture, microbial quality, peroxidase activity, and sensory qualities were analyzed. The results were also compared to those for samples submerged in distilled water and the samples treated with 120-ppm chlorine solution widely used in the industry. It was found that ascorbic acid and cinnamon oil delayed the browning of fresh-cut apples effectively when being applied in the starch/dHG-based edible coating solutions. In combination with calcium chloride, starch/dHG coated fresh-cut apples retained satisfactory firmness. Incorporation of cinnamon oil in starch/dHG coatings significantly reduced the growth of microorganisms, respiration rate, CO₂, and ethylene production of fresh-cut apples, but these apple pieces received lower scores in overall preference during sensory evaluation. Among the starch/dHG-based active coatings studied, starch/dHG coatings with ascorbic acid and calcium chloride are suggested for fresh-cut apples, as they could enhance qualities in terms of color and firmness, and prolong the shelf life up to 5–7 days by providing reasonable microbial quality.