中原地区10种水果维生素C含量分析

采用2,6-二氯靛酚法分别对苹果、草莓、樱桃、山楂、西瓜、猕猴桃、青葡萄、鸭梨、油桃、圣女果共10种中原水果维生素C含量进行测定。结果显示所测水果中Vc含量为4.85mg/100g～62.92mg/100g。其含量高低顺序为：猕猴桃>山楂>草莓>圣女果>樱桃>鸭梨>苹果>西瓜>青葡萄>油桃。猕猴桃的Vc含量最高,达到62.92mg/100g,其次是山楂,为47.85mg/100g,油桃含量最低,为4.85mg/100g。猕猴桃、山楂、草莓等Vc含量高的水果有望成为人们合理膳食及补充Vc的主要食源。     

10种郑州市售水果维生素C含量分析

目的以郑州市售的10种水果为研究对象,对其维生素C含量进行分析,以期筛选Vc含量高的食源,为人们合理膳食及补充Vc提供理论依据。方法采用2,6-二氯靛酚法进行维生素C含量的测定。结果测定结果显示所测10种水果中Vc含量范围为4.85 mg/100g~62.92 mg/100 g。含量高低顺序为:猕猴桃山楂草莓圣女果樱桃鸭梨苹果西瓜青葡萄油桃。猕猴桃的Vc含量最高,达到62.92 mg/100 g,其次是山楂,为47.85 mg/100g,油桃含量最低,为4.85 mg/100 g。结论猕猴桃、山楂、草莓等水果有较高的Vc含量。     

15种水果和33种蔬菜的抗氧化活性研究

目的:比较不同水果蔬菜的抗氧化活性.方法:采用DPPH法和FRAP法对15种水果,33种蔬菜的抗氧化活性进行了测定比较,并且分析了抗氧化活性和VC含量的关系.DPPH法测量的结果表明:所测水果中抗氧化活性最强的为花红李,最弱的为水晶梨;所测蔬菜中抗氧化活性最强的为豆角,最弱的为黄瓜、冬瓜;FRAP法测量的结果表明:所测水果中抗氧化活性最强的为橙子,最弱的为水晶梨和香梨:所测蔬菜中抗氧化活性最强的为红辣椒,最弱的为丝瓜和黄瓜.结论:不同的方法测出的抗氧化活性的大小不同,水果和蔬菜中的抗氧化活性成分值得进一步研究.     

漫话水果入肴

近年来,水果入肴已成为时尚。它给人以滋味新颖、清新自然、典雅高洁之感,因而深受人们欢迎。常用的水果有:苹果、梨、香蕉、柑桔、芒果、菠萝、柿、蜜桃、杨梅、山楂、李子、杨桃、樱桃、石榴、桑椹、葡萄、枇杷、荔枝、桂圆、猕猴桃、海棠、西瓜、香瓜、哈密瓜等不下几十种。此外,还有美国的蛇果、红提、布林果,马来西     

水果红茶菌饮料抗氧化活性分析

对添加苹果、香橙、猕猴桃原汁的红茶菌饮料进行总酚及抗氧化活性的测定,结果表明3种水果红茶菌饮料的总酚与还原力的变化呈正相关关系,其中猕猴桃红茶菌饮料的总酚最高,可达319 mg/m L,其次香橙红茶菌饮料的总酚达308 mg/m L,苹果红茶菌饮料的总酚达305 mg/m L。3种水果红茶菌饮料的抗氧化活性结果表明:对DPPH自由基的清除能力和对(O2—·)清除能力达到90%,对(·OH)清除能力猕猴桃红茶菌饮料最强,香橙红茶菌饮料次之,苹果红茶菌饮料最弱,但也在30%以上。     

超高压处理对不同品种猕猴桃浆多酚含量及其抗氧化活性的影响

对4种猕猴桃浆(黄心猕猴桃、绿心猕猴桃、红阳猕猴桃、聚香猕猴桃)进行超高压(500MPa,20min)处理,分析超高压处理前后猕猴桃浆中游离酚、结合酚含量及其抗氧化活性变化。结果表明:超高压处理能显著提高猕猴桃浆多酚含量(P<0.05),其中,黄心猕猴桃游离酚含量增加了78.68μg/mL,聚香猕猴桃结合酚含量提高了15.58μg/mL。DPPH自由基清除率、还原力和ABTS+清除率实验表明:4种猕猴桃游离酚抗氧化活性强于其结合酚的,超高压处理可提高其抗氧化活性,但效果不显著。     

水果好吃有讲究

水果种类繁多,根据果实的形态和生理特征可分为6个亚类:仁果类,如苹果、梨、山楂、海棠果等;核果类,如樱桃、梅、杏、李、桃、枣等;浆果类,如葡萄、草莓、猕猴桃、沙棘、柿子、石榴、无花果、桑椹等;柑橘类,如橙、柑橘、柚、柠檬等;亚热带和热带水果,如荔枝、香蕉、菠萝、芒果、椰子、番石榴、枇杷、洋桃;瓜果类,如西瓜、甜瓜、哈密瓜、黄金瓜等。说它们好吃是因为它们都有特别的色、香、味、形,非常诱人;都有各自的营养成分,具有营养价值;还含有各自的特殊成分,使之具有保健与药用价值。因此它们备受人们的喜爱,但对水果的食用是有讲究的,…     

不要上了劣质果醋的当

果醋是以水果如苹果、山楂、葡萄、梨、杏、柑橘、猕猴桃等,或果品加工下脚料为主要原料,利用现代生物技术发酵而成的一种营养丰富、风味优良的饮料。果醋由于经水果发酵而来,一方面保留了水果中的矿物质和大部分维生素以及生物活性物质,     

酶法液化制汁与果汁化学成分的相关性

本试验以苹果、草莓、山楂、枣等原料，对酶法液化制汁为果汁化学成分含量的相关关系进行了研究。结果表明，采用酶法液化法制汁与传统方法制汁比较，可提高出汁率，可溶性固形物，总糖、总酸的含量，并可显著提高混汁纤维素的含量，具有良好的酶效应，提高果汁总糖量和出汁率的酶效应，受加酶量，处理温度和时间的影响。     

高歌猛进的中国小品种果汁业

中国水果年产量在9000万吨左右,约占世界水果总产量的15%。中国果汁年产量和出口量均占全球总量的60%左右,均位居世界第一,每年出口额超过10亿美元。而中国梨和梨汁的出口也领先于世界前列。占全球梨产量的50%以上。小品种果汁作为我国浓缩果汁出口的一项重要的生力军异军突起,中国苹果、猕猴桃种植面积居世界之首,而陕西省猕猴桃种植面积为中国最大,陕西省猕猴桃产量占中国总产量的50%,这便为陕西小品种果汁业     

Effect of cultivar and fruit storage on basic composition of clear and cloudy pear juices

BackgroundPears due to low acidity are a suitable raw material for the production of multifruit nectars thus it is justified to determine the chemical composition and investigate the effect of cultivar and fruit maturity on juices quality.MethodsJuices from ‘Alexander Lucas’ and ‘Conference’ cultivars were produced after harvest and after 3 months of pears storage.ResultsAverage yield of clear juices was 76.4% for ‘Conference’ cultivar and 74.3% for ‘Alexander Lucas’. In the case of cloudy juices, the yield was lower by about 3%. Processing of ‘Conference’ cv. from stored fruit resulted in yield decrease compared to fruits after harvest; this was not in case of ‘Alexander Lucas’ in 2008, where juices produced from stored fruits were characterized by a higher yield compared to fresh fruit.Total solids content in clear juices was 125–135 g/L and 135–141 g/L for cloudy juices. ABTS^●+ and total phenolics analysis showed that cloudy juices were characterized by a higher antioxidant activity and phenolics content than the clear ones.ConclusionPear storage, on the contrary to apples, does not decrease their suitability for cloudy juice production. Cloudy juices as a rule have higher antioxidant activity than the clear ones.     

Evaluation of Penicillium expansum isolates for aggressiveness, growth and patulin accumulation in usual and less common fruit hosts

Experiments were carried out in vivo and in vitro with four isolates of Penicillium expansum (I 1, E 11, C 28 and I 12) to evaluate their aggressiveness, growth and patulin accumulation in both usual (pears and apples) and less common hosts (apricots, peaches, strawberries and kiwifruits) of the pathogen. The 75% of isolates showed the ability to cause blue mould in all tested hosts. In particular, C 28 and I 1 were the most and the least aggressive isolates, respectively (52.9 and 10.6% infection and 20.7 and 15.4 mm lesion diameters). ‘Candonga’ strawberries and ‘Pinkcot’ apricots showed the largest lesion diameters (29.8 and 25.3 mm), followed by ‘Conference’ pears, ‘Spring Crest’ peaches and ‘Abate Fetel’ pears. With the exception of ‘Candonga’ strawberries, the formation of colonies and mycelial growth of P. expansum isolates on fruit puree agar media (PAMs) was stimulated in comparison to a standard growth medium (malt extract agar, MEA). Two of the most aggressive isolates in our assays (I 12 and C 28) showed the greatest accumulation of patulin both in vitro and in vivo, while the least aggressive isolate (I 1) produced patulin only in a few growth media and cvs. Patulin concentration on fruit PAMs was higher than patulin detected in infected fruit tissues. Apple PAMs were the more favorable substrates for patulin accumulation in vitro (maximum concentration 173.1 and 74.1 μg/mL in ‘Pink Lady and ‘Golden Delicious’ PAMs, respectively) and ‘Pink Lady’ apples inoculated with the isolate E 11 showed the greatest accumulation of patulin in the whole in vivo assay (33.9 μg/mL). However, infected tissue of cv Golden Delicious showed lower average accumulation of patulin (1.7 μg/mL) than that of cv Pink Lady (19.1 μg/mL), and no significant differences in patulin concentrations were found among ‘Golden Delicious’ apples and tested cvs of pears, kiwifruits and strawberries. Peaches were highly susceptible to patulin accumulation, showing average concentrations of 27.4 and 18.6 μg/mL in vitro and in vivo, respectively. Apricots were also consistently positive for patulin accumulation, both in vitro (average values of 20.1 μg/mL) and in vivo (average values of 9.4 μg/mL). Our study showed the potential of some less common hosts of P. expansum (in particular peaches and apricots) to support patulin production, indicating that a steady monitoring of patulin contamination should be carried out in fruit substrates other than apples and pears.     

Comparison of the polyphenolic composition and antioxidant activity of European commercial fruit juices

Thirty six commercial European fruit juices were tested to ascertain their antioxidant capacity and polyphenolic composition. Six of the products were labelled 100% pomegranate juice, the others included 20 brands of diluted pomegranate juice or pomegranate blended with other fruit juices and 10 different non-pomegranate fruit juices. The antioxidant capacity of all the juices was determined while anthocyanin, ellagitannin and ellagic acid profiles of the 26 pomegranate juices and pomegranate juice blends were obtained using HPLC-PDA-MS(2). Additional analysis was conducted on seven of the juices using HPLC with an on-line antioxidant detection system. Three of the "pure" pomegranate juices had the highest ellagitannin content and the highest antioxidant capacity. Only one of these three juices was rich in anthocyanins. The other "pure juices" had differences in their HPLC "pomegranate" fingerprint and also had a lower antioxidant capacity, in some cases lower than that of some of the blended juices. Vitamin C rather than phenolic compounds was the major contributor to the antioxidant capacity for some of the juices. Statistical analysis of both the antioxidant assay and the HPLC on-line antioxidant data demonstrated that the ellagitannins were the major antioxidants in the pomegranate juices. The complexity of the polyphenolic profile of pomegranates necessitates the use of HPLC-PDA-MS(2) for a thorough evaluation of juice composition and authenticity.     

QUALITY OF ‘GALA’ APPLES AS INFLUENCED BY HARVEST MATURITY,STORAGE ATMOSPHERE AND CONCOMITANT STORAGE WITH ‘BARTLETT’ PEARS1

Controlled atmosphere (CA) storage for 45 or 90 days following harvest reduced quality losses for both ‘Gala’apples and ‘Bartlett’pears compared with fruit from regular atmosphere (RA) storage. Fruit stored in CA were firmer, had higher acidity and less color change than fruit from RA storage. Apples and pears stored together in CA maintained good quality and compared favorably with apples or pears stored separately. There was no difference in fruit quality between fruit stored at 1% O₂ and 1% CO₂ compared with fruit stored in 2% O₂ and 3% CO₂. Fruit harvested at a more advanced stage of maturity deteriorated more quickly in storage than earlier harvested fruit. A combination of 45 days in CA followed by 30 days RA resulted in apples that were superior in quality to apples stored for 75 days in RA alone.     

Concentration of morpholine residues in major fruits and juices and its dietary exposure in China

Morpholine is a common chemical used as emulsifier in the preparation of wax coatings for some fruit to help them remain fresh and protect against insects and fungal contamination. It has been reported that morpholine has acute toxic effects on rodents. In the present study, morpholine concentrations were analysed in fruits (citrus fruits, apples, strawberries and grapes) and juices (apple juice and orange juice) in order to determine dietary exposure among the Chinese population. A total of 732 fruit and juice samples were collected during 2015–2016, which covered major foods in China. Fruit and juice consumption data were taken from China National Nutrient and Health Survey (2002) and include data from 16,407 fruit or juice consumers. It was found that mean dietary exposure to morpholine residues from fruits and/or juices for general Chinese consumers and children 2–6 years old were 0.42 and 1.24 µg/kg bw/day, respectively. The 97.5% intake in general Chinese consumers and children 2–6 years old were 2.25 and 6.90 µg/kg bw/day, respectively. The primary food sources of the morpholine dietary intake of general Chinese consumers were citrus fruits (57.4%) and apples (40.8%). These findings suggested that dietary exposure to morpholine in the Chinese population was lower than the acceptable daily intake of morpholine, and there are no health concerns.     

Hygienic significance of patulin in food. 2. Occurrence of patulin in fruit and vegetables]

The analyses of more than 200 samples of various foods of plant origin showed that patulin was contained in 36% of the fresh and canned fruits infested with mould, and in 7% of the vegetables. Besides apples, pears, plums, peaches and tomatoes contained also patulin. In organoleptically impeccable fruit juices, the contamination rates were 40% (for apple juice) and 16% (for the other juices, such as sour cherry, currant, sea buckthorn juices). The patulin content varied from 20 to 200 microgram/l, the mean value being 80 microgram/l. It ranged from 0.1 to 5 microgram/g in apples and sterile apple preserves. The authors discuss the hygienic-toxicologic significance of these findings, and suggest to include patulin in the examination of foods for mycotoxins, stipulating a permissible value.     

Changes on indigenous microbiota,colour, bioactive compounds and antioxidant activity of pasteurised pomegranate juice

Juices prepared from arils of ‘Mollar’ pomegranates were analysed for naturally occurring microorganisms, CIE Lab colour parameters, total phenols, anthocyanins and punicalagins, ellagic acid content and antioxidant capacity before and after low-, mild- and high-temperature pasteurisations (LTPs, MTPs and HTPs): 65, 80 and 90 °C for 30 or 60 s. Mean aerobic plate count (APC), yeast and mold count (YMC), and lactic acid bacteria (LAB) for fresh juices were 5.7, 5.36 and 4.0 log CFU/mL, respectively. MTPs and HTPs were sufficiently effective to decrease APCs to nil or negligible levels. An increase in CIE a values and decrease in CIE b values were the characteristic colour changes in heat-treated juices. The effect of pasteurisations showed that total phenols, punicalagins and ellagic acid were not much affected by thermal processing. Total anthocyanin content and antioxidant capacity were substantially and significantly influenced by the heat treatment applied. A linear relationship was observed between Trolox equivalent antioxidant capacity (TEAC) values and total anthocyanins, suggesting that they contributed strongly to the antioxidant capacity of pomegranate juice.     

Quantitative analysis of mycoflora on commercial domestic fruits in Japan

A comprehensive and quantitative analysis of the mycoflora on the surface of commercial fruit was performed. Nine kinds of fruits grown in Japan were tested. Overall fungal counts on the fruits ranged from 3.1 to 6.5 log CFU/g. The mean percentages of the total yeast counts were higher than those of molds in samples of apples, Japanese pears, and strawberries, ranging from 58.5 to 67.0%, and were lower than those of molds in samples of the other six fruits, ranging from 9.8 to 48.3%. Cladosporium was the most frequent fungus and was found in samples of all nine types of fruits, followed by Penicillium found in eight types of fruits. The fungi with the highest total counts in samples of the various fruits were Acremonium in cantaloupe melons (47.6% of the total fungal count), Aspergillus in grapes (32.2%), Aureobasidium in apples (21.3%), blueberries (63.6%), and peaches (33.6%), Cladosporium in strawberries (38.4%), Cryptococcus in Japanese pears (37.6%), Penicillium in mandarins (22.3%), and Sporobolomyces in lemons (26.9%). These results demonstrated that the mycoflora on the surfaces of these fruits mainly consists of common pre- and postharvest inhabitants of the plants or in the environment; fungi that produce mycotoxins or cause market diseases were not prominent in the mycoflora of healthy fruits. These findings suggest fruits should be handled carefully with consideration given to fungal contaminants, including nonpathogenic fungi, to control the quality of fruits and processed fruit products.     

Influence of ultra high pressure processing on fruit and vegetable products

Data are shown of the impact of ultra high pressure (UHP) processing on anti-mutagenic and anti-oxidative factors, sugars, ascorbic acid and carotenoids, in products from oranges, apples, peaches, mixed citrus juices, carrots, tomatoes, strawberries and raspberries. In most cases high pressure did not induce loss of beneficial substances in the fruit and vegetable matrices. Incomplete pressure inactivation of invertase resulted in total disappearance of sucrose during storage of UHP treated raspberries.     

Effects of apple and pear varieties and pH on patulin accumulation by Penicillium expansum

BACKGROUND: Accumulation of patulin in apples and pears and subsequently in their by‐products is caused mostly by Penicillium expansum which causes blue mould. Fruit pH and other parameters are sometimes characteristic of a certain variety and thus the use of particular varieties might affect patulin content in the final products. The aim of this study was to evaluate the influence of fruit variety and pH on patulin accumulation. Patulin accumulation in both apple and pear juices at different pH and also in different apple varieties (Golden, Gala and Fuji) and pear varieties (Blanquilla and Conference) was assessed. RESULTS: The pH of juices significantly influenced patulin accumulation, especially in apple juice in which the highest amounts of patulin were detected at pH 3.5. In fruits, the pH values of the substrate were determinant only under cold storage. Thus, Golden apples, which presented a lower pH, accumulated more patulin at 1 °C. However, this trend was not observed at other temperatures in which varieties with higher amounts of organic acids (Golden and Fuji apples) accumulated most patulin. In the pear varieties, significant differences in pH did not lead to significant differences in patulin accumulation. CONCLUSION: Although pH influences patulin accumulation, other factors such as organic acid content may play an important role. Concerning the apple and pear varieties we studied, it seems that rather than variety, other parameters like pH or acidic content may be more important. These parameters vary significantly depending on the degree of ripeness of the fruit. Gala apple, which is used in Spanish juice production, was the only variety that accumulated dramatically higher amounts of patulin. Copyright © 2008 Society of Chemical Industry