Radiation preservation of foods of plant origin. III. Tropical fruits: bananas, mangoes, and papayas

The current status of research on the use of ionizing radiation for shelf life improvement and disinfestation of fresh tropical fruits like bananas, mangoes, and papayas are reviewed. The aspects covered are influence of maturity and physiological state of the fruits on delayed ripening and tolerance to radiation; varietal responses; changes in chemical constituents, volatiles, respiration, and ethylene evolution; biochemical mechanisms of delayed ripening and browning of irradiated fruits; and organoleptic quality. The efficacy of the combination of hot water dip and radiation treatments for control of postharvest fungal diseases are considered. The immediate potential of radiation as a quarantine treatment, in place of the currently used chemical fumigants, for disinfestation of fruit flies and mango seed weevil are discussed. Future prospects for irradiation of tropical fruits are discussed in the light of experience gained from studies conducted in different countries.     

百香果山药复合果酒酿造工艺研究

以百香果和山药为原料进行复合果酒酿造工艺研究.研究结果表明,百香果汁与山药汁的最佳配比为1：2;最佳发酵工艺为初始糖度28％,酵母接种量0.03％,发酵温度25℃,发酵时间8d.成品果酒色泽呈浅黄色,有典型的百香果和山药风味,酒香清醇,口感清爽,酸甜适中,澄清透亮.果酒酒精度14.03％vol,DPPH自由基清除率98.83％.     

Radiation preservation of foods of plant origin. Part IV. Subtropical fruits: citrus, grapes, and avocados

Current information on the use of ionizing radiation for improving the storage of subtropical fruits like citrus, grapes, and avocados is reviewed. The feasibility of applying radiation either alone or in combination with other physical or chemical treatments for the control of postharvest fungal diseases is considered. Irradiation effects on the physiology of the fruits as related to respiration, ethylene evolution, changes in major chemical constituents, and quality are discussed. The recent trends in the possible use of irradiation as an alternative treatment to chemical fumigants for disinfestation of citrus and avocados and the prospects for the future application of irradiation for preservation of some of these fruits are outlined.     

带壳百香果与甘蔗汁混酿复合果酒工艺研究

将带壳百香果和甘蔗汁作为原料酿造复合果酒,并研究其发酵工艺。 运用单因素试验和正交试验对发酵破壳时间、原料配比、原料初始含糖量、主发酵温度及主发酵时间进行优化。 结果表明,百香果甘蔗复合果酒的最优工艺条件为：百香果发酵破壳时 间5d,百香果与甘蔗汁配比1∶3（g∶mL）,调节原料初始含糖量至32.5%,于发酵温度24℃条件下发酵9d。 在此最佳工艺条件下,百香果甘蔗复合果酒感官评分达到79分,酒精度达到14.1%vol,色泽呈玫瑰红色,澄清透亮,具有典型的百香果浓郁香气和甘蔗汁的清 香风味。     

Browning Potential,PPO, Catalase and Acid Phosphatase Activities during Ripening of Non-chilled and Chilled Avocado

During storage at 17°C, an increase in respiration and ethylene production and a decrease in firmness occurred sooner in avocados chilled previously than in non-chilled ones. The browning potential of avocado mesocarp changes markedly during ripening of both non-chilled and chilled fruits, reaching the same maximal level in both groups. However, non-chilled ripened avocados are characterised by a much lower browning potential than ripened chilled fruits. The changes in browning potential during ripening are associated with larger changes in polyphenol oxidase (PPO) and catalase than in acid phosphatase activities. The levels of PPO and of catalase detected during ripening are about the same in non-chilled and chilled avocado, yet the former produced much more ethylene than the latter, implying that the level of these enzymes per se does not determine the level of ethylene produced by the fruit.     

Postharvest shelf-life extension of avocados using methyl cellulose-based coating

Edible coatings regulate water vapor, oxygen and carbon dioxide transfer in or out of the produce thereby influencing the ongoing respiratory activity and produce quality. The objective of this study was to evaluate the effect of a methyl cellulose-based coating on the respiration rate, color and texture of avocados stored at room temperature. Avocados were initially surface disinfected, washed and air-dried. They were then immersed in the coating solution for 1 min at 20 °C, air-dried for 10 min and stored at 20 °C in an open box. At 2-day intervals, fruits were removed and evaluated for respiration rate, color and texture. Respiration rate was evaluated by measuring the rate of CO₂ produced from a given quantity of fruits per unit time. Color and texture of avocados were measured using instrumental techniques. Coated avocados demonstrated lower respiration rates, greener color and higher firmness as compared with the uncoated control during the entire storage. The appearance of brown spots and mesocarp discoloration normally associated with fruit ripening were delayed in the coated fruits.     

1-MCP处理对花红采后常温贮藏品质的影响

为了研究1-甲基环丙稀(1-MCP)处理对花红常温贮藏品质的影响,以不同成熟度花红为材料,研究经1-MCP(1.0 μL/L)熏蒸处理后对花红在常温(20±1) ℃贮藏时品质上的影响。结果表明:同对照组(未熏蒸)相比,1-MCP处理可以有效提高两种成熟度果实色泽,减缓腐烂率和失重率的增加,维持果实硬度(5.68~9.18 kg·cm-2),降低果实呼吸强度,并推迟(10~15 d)呼吸强度峰值的出现,同时延缓可滴定酸(TA)含量、维生素C(V_C)含量和可溶性固形物含量(SSC)的下降。在两种成熟度花红果实中,以低成熟度果实贮藏效果最好,具有较低的失重率与腐烂率,果实口感清脆,酸甜适度,果皮色泽红青亮丽。     

百香果—苹果复合发酵型乳饮料工艺优化及抗氧化性研究

目的:制作一款新型百香果、苹果发酵乳饮料。方法:以百香果、苹果和纯牛奶为原料,以感官评价、蛋白质含量为指标,利用模糊数学评价法,考察苹果汁添加量、百香果汁添加量、蔗糖添加量、发酵时间、菌种接种量对百香果—苹果风味发酵乳感官品质的影响,并对发酵乳的抗氧化性及各项指标进行检测。结果:百香果—苹果风味发酵乳的最佳配方为纯牛奶82.59%,百香果汁2.35%,苹果汁8.00%,蔗糖7.00%,增稠剂0.06%,菌种0.002 06%,发酵时间6.50 h。此条件下,发酵乳的感官评分为8.99,蛋白质含量为3.12 g/100 g,其理化指标和卫生指标均符合相关国标要求。抗氧化性结果表明,百香果—苹果乳饮料发酵后对DPPH自由基和羟自由基的清除率均比发酵前有所提升,分别为77.7%,45.7%。结论:最佳配方下得到的发酵乳呈淡黄色,具有良好的组织状态,无乳清析出,不分层,具有百香果和苹果的清香和发酵乳特有风味,酸甜比例合适。     

间歇升温对香蕉李贮藏中生理生化变化的影响

以香蕉李为试材,研究了不同的间歇升温对低温下贮藏的李果实生理生化的影响。结果显示:对照果在冷藏20d时,呼吸强度和乙烯释放量逐渐增加,相对电导率明显上升;说明冷害已经开始启动,而且随着贮藏时间的延长,冷害指数显著增大,冷害程度明显加剧,果实正常后熟过程受阻。经过间歇升温的果实,果皮逐渐由绿变黄,再由黄转红而逐渐完成后熟过程。间歇升温到10℃虽然对冷害症状有所缓解,但李果实更易成熟老化,可溶性固形物含量快速下降,呼吸强度明显高于冷害果,膜透性增加最快,贮藏后期老化的果实更易发生冷害。而间歇升温到18℃的李果实呼吸强度、膜透性、贮藏初期的乙烯释放量明显受到抑制,可溶性固形物含量较高,冷害指数显著下降,说明间歇升温到18℃能有效地抑制李果实冷害的发生,延缓了李果实的衰老进程,保持了李果实良好的贮藏品质。     

产自攀枝花市的四种水果果干品质特性分析

本研究分析评价了芒果干、木瓜干、草莓干和桑葚干的主要营养成分,利用质地剖面法(Texture Profile Analysis,TPA)分析果干的内部结构,并结合感官和微生物学评价对果干的品质进行综合分析。结果表明,四种果干均为高糖产品,草莓干的可溶性糖和总糖含量最高,分别为55.66%和97.26%。桑葚干的蛋白质和风味氨基酸的含量均高于其他三种果干,且为典型的高K、低Na(K/Na为4827)食品。而芒果干中粗蛋白含量最低,但其EAA/NEAA高达55.51%,说明芒果干氨基酸组成较为合理。此外,木瓜干硬度、咀嚼性、内聚性均最大,果肉保持完整的能力最强,但适口性最差。最后,四种果干中重金属及致病菌等限量标准均未超标。本研究通过对产自攀枝花的四种果干品质特性进行分析,明确果干的各项指标,从而为果干的市场应用提供理论指导。     

Enzymatic hydrolysis of edible Passiflora fruit glycosides

The combined action of Hemicellulase REG 2 and sweet almond glucosidase containing β-d-glucopyranosidase, α-l-rhamnopyranosidase, α-l-arabinopyranosidase and α-l-arabinfuranosidase activities allowed release of most of the volatile compounds bound as aglycones in edible Passiflora fruits. Great variability between the four species studied, P. edulis, P. edulis f falvicarpa, P. ligularis, P. molissima, was noticed. 2,5-Dimethyl-4-hydroxy-3-(2H) furanone (furaneol) was identified for the first time in bound form in purple and yellow passion fruit. Only geraniol was identified as the aglycone in P. molissima. and no terpenol is present in the hydrolysate obtained from P. ligularis. Several terpene diols: 2,6-dimethyl-1,8-octanediol, (E)- and (Z)-2,6-dimethylocta-2,7-diene-1,6-diol, 2,6-dimethylocta-3,7-dien-2,6-diol and 2,6-dimethylocta-1,7-dien-3,6-diol have been identified in both purple and yellow passion fruit and small amounts of (Z)-2,6-dimethylocta-2,7-diene-1,6-diol are present in P. molissima. α-Ionol derivatives oxygenated in position 3 seem to be characteristic of purple passion fruit whereas β-ionol compounds oxygenated in position 3 are the major norisoprenoids identified as the aglycone in yellow passion fruit. The bound norisoprenoid content of P. ligularis and P. molissima is low. Important concentrations of bound aromatic alcohols are found in purple and yellow passion fruit whereas phenolics can be considered as characteristic of purple varieties. ©     

1-MCP处理对百香果贮藏品质的影响

为研究不同浓度1-MCP结合BOPP保鲜袋处理对采后百香果保鲜效果的影响,使用不同浓度(0、0.3、0.6、0.9 μL/L)1-甲基环丙烯(1-MCP)熏蒸百香果12 h后装入BOPP保鲜袋,于(5±1) ℃下贮藏。结果表明:不同浓度1-MCP结合BOPP保鲜袋处理均可降低果实失重率,保持果实具有较好的色泽,同时可以维持百香果果实较高的TSS、总酸、V_C和总糖含量。其中0.6 μL/L的1-MCP熏蒸12 h并采用BOPP保鲜袋包装的保鲜效果最佳。     

The maturity of avocados—a general review

Avocado maturity is reviewed from a broad perspective. Firstly the terminology related to avocado maturity is discussed, including development, maturation and maturity, ripening, senescence and quality. The distinctions between maturation, maturity and ripening are emphasised. Maturity is taken to mean acceptability of fruit for consumers rather than for processing. Secondly the effects of the properties of avocado trees and fruits on the determination of maturity are outlined. The subjects include origin, distribution and importance of avocados, anatomy, oil content, lipids and other constituents, flowering, seeding, growth, ripening and respiration. Especially relevant to maturity are the lack of external changes in avocados on maturing; the fact that fruits only ripen after picking because the attached fruit is in a juvenile state resulting from the avocado's growth by cell division and cell enlargement; the prolonged flowering causes wide variability in age between fruits. Thirdly the main methods of assessing maturity are considered. Subjects discussed are oil content and properties, dry matter content, sugar content, destructive physical tests and non-destructive physical tests, especially picking date. Relevant changes in oil, water and sugars during ripening are also considered. Oil content and picking date have been the indices most studied and they seem well related to sensory tests. Other possible indices are dry matter content, iodine number of oil and cuticular wax concentration. Regulatory consequences are considered, especially for the legal minimum oil content in California, the oil contents for different varieties in Queensland and Israel and the comprehensive picking date system for specified weight fruits used in Florida.     

Quality evaluation of frozen guava and yellow passion fruit pulps by NIR spectroscopy and chemometrics

The present study investigated the application of near infrared spectroscopy as a green, quick, and efficient alternative to analytical methods currently used to evaluate the quality (moisture, total sugars, acidity, soluble solids, pH and ascorbic acid) of frozen guava and passion fruit pulps. Fifty samples were analyzed by near infrared spectroscopy (NIR) and reference methods. Partial least square regression (PLSR) was used to develop calibration models to relate the NIR spectra and the reference values. Reference methods indicated adulteration by water addition in 58% of guava pulp samples and 44% of yellow passion fruit pulp samples. The PLS models produced lower values of root mean squares error of calibration (RMSEC), root mean squares error of prediction (RMSEP), and coefficient of determination above 0.7. Moisture and total sugars presented the best calibration models (RMSEP of 0.240 and 0.269, respectively, for guava pulp; RMSEP of 0.401 and 0.413, respectively, for passion fruit pulp) which enables the application of these models to determine adulteration in guava and yellow passion fruit pulp by water or sugar addition. The models constructed for calibration of quality parameters of frozen fruit pulps in this study indicate that NIR spectroscopy coupled with the multivariate calibration technique could be applied to determine the quality of guava and yellow passion fruit pulp.     

响应面优化百香果果皮果脯制备工艺

为实现百香果果皮的高值化利用，本研究以百香果皮为主要原料，开发具有百香果特征风味的果脯产品。以感官评分作为主要评价指标，通过单因素实验研究甜味剂、柠檬酸添加量以及糖煮时间和烘干时间对百香果果脯品质的影响，确定最佳工艺配方。在单因素的基础上与响应面相结合优化百香果果脯的制作工艺，最后对产品理化指标及微生物等相关指标进行品测。结果表明，百香果果皮果脯最优工艺:甜味剂添加量为25%，柠檬酸添加量为0.8%，糖煮90 min，65 ℃下烘干12 h。在此条件下所得产品口感酸甜，软糯，风味浓郁，理化指标及微生物指标均符合相关的标准要求。此产品的开发为百香果皮综合利用提供思路，为百香果产业高附价值开发提供参考。     

HS-SPME-GC-MS测定三种类型百香果果实挥发性风味成分

为探讨不同类型百香果挥发性风味成分的组成及相对含量,采用顶空固相微萃取-气相色谱-质谱联用对紫、红和黄百香果中挥发性风味成分进行了测定,并结合相对气味活度值（ROVA）探究各成分对样品总体风味的贡献。结果表明,三种类型百香果中共鉴定出32种挥发性风味成分,主要包括酯类12种、烯烃类7种、烷烃类2种、醇类8种、酮类3种,其中共有成分有16种。根据挥发性成分的ROVA,黄百香果的关键挥发性成分（ROVA≥1）有5种,分别为丁酸乙酯、己酸乙酯、乙酸乙酯、芳樟醇和β-紫罗兰酮;但紫、红百香果中关键挥发性风味成分均为4种,分别为丁酸乙酯、己酸乙酯、乙酸乙酯和β-紫罗兰酮。而且,百香果中还存在对其香气起重要修饰作用成分（0.1≤ROVA≤1）,如辛酸乙酯、乙酸己酯、丁酸己酯、β-月桂烯、D-柠檬烯。这些关键风味成分和重要修饰成分共同构成百香果的特征香气,且不同类型间百香果挥发性风味成分差异较大。     

葡萄百香果酒的酿造工艺研究

以葡萄和百香果为原料,复合发酵开发一款风味独特的果酒。通过单因素试验和二次通用旋转组合试验优化复合果酒酿造工艺,并对产品质量进行评定。结果表明,葡萄百香果酒的最佳工艺参数为酵母添加量（葡萄酒活性干酵母∶耐高温活性干酵母=1∶1）0.4%、葡萄汁:百香果汁1∶4（V/V）,初始糖度24 °Bx、发酵温度23 ℃、发酵时间7 d,在此优化条件下,得到的葡萄百香果酒果味浓郁、色泽金黄、酸甜适中、口感清爽,感官评分为84.35分,其酒精度为（12.3±1.3）%vol,糖含量（3.08±0.38）g/L,总酸含量为（6.65±0.29）g/L,符合国家标准要求,是一款品质较佳的风味果酒。     

响应面法优化圣女果百香果复合发酵饮料工艺及品质分析

在单因素试验的基础上,应用响应面分析法对圣女果百香果复合发酵饮料工艺进行优化,并对发酵后的品质指标进行了测定。结果表明,各因素对圣女果百香果复合发酵饮料中感官评分影响大小依次为果汁配比＞发酵时间＞菌种添加量＞发酵温度;最优发酵工艺条件为：圣女果:百香果汁配比6∶1、发酵时间31 h、菌种添加量3%、发酵温度37 ℃。在此优化条件下,圣女果百香果复合发酵饮料感官评分达82分,酸甜宜口、风味独特,发酵后复合发酵饮料的pH、可溶性固形物、总酸、还原糖、总酚、总黄酮、番茄红素、维生素C、乳酸菌总数分别为3.30、11.50%、5.95 g/100 ml、6.68 g/100 g、40.03 mg/100 g、6.83 mg/g、32.83 mg/100 g、23.31 mg/100 g、5.2×106 CFU/mL。     

百香果全果酒发酵工艺优化及体外抗氧化性比较分析

以紫皮百香果（Passiflora edulis）为原料发酵百香果全果酒,通过单因素试验结合响应面法,确定百香果全果酒的最适发酵工艺,并通过四个抗氧化体系（DPPH·、ABTS+·、·OH、还原能力）来评价其与百香果果汁酒和原汁的抗氧化活性。结果表明,百香果全果酒最适发酵工艺条件为初始糖度21%、酵母接种量0.04%、发酵温度29 ℃、发酵时间5 d。在此优化工艺条件下,百香果全果酒酒精度为11.9%vol;在四种抗氧化体系中,自由基清除率和还原能力均随样品体积的增加而增大,抗氧化活性的大小顺序为全果酒＞果汁酒＞原汁。     

1-MCP和预贮对深州蜜桃采后生理和品质的影响

为保持深州蜜桃冷藏期间良好的品质, 延长贮藏时间, 采用1 . 0 μ L / L 1 - 甲基环丙烯
（1-methylcyclopropene,1-MCP）熏蒸和预贮（8 ℃、5 d转入0 ℃）的方法对采后深州蜜桃进行处理,测定0 ℃冷
藏期间果实呼吸速率、乙烯释放速率和品质的变化。结果表明,1-MCP处理能够明显抑制桃果实冷藏期间的呼吸速
率和乙烯释放速率,推迟呼吸高峰期的出现;同时延缓了果实软化,抑制可溶性固形物含量上升,降低了果实的褐
变指数和腐烂指数;预贮促进了果实后熟,但预贮和1-MCP处理均明显降低了贮藏期果实褐变度和酚类物质含量,
二者结合处理对抑制果实褐变效果最佳。