桑葚汁、茱萸汁和沙棘汁中的总黄酮含量测定分析

在硝酸铝-醋酸钾分散系中,用乙醇浸提,采用可见光分光光度计测定桑葚汁、茱萸汁和沙棘汁3种果汁中的总黄酮含量.在波长500 nm条件下,以芦丁为标准品做标准曲线得回归方程:Y=0.5705X-0.0065,R2=0.9995.分别测得桑葚汁中的黄酮含量为891.710 mg/100mL、茱萸汁为147.349 mg/100mL、沙棘汁为321.647mg/100mL.     

Vacuum impregnation on apples with grape juice concentrate: Effects of pressure,processing time,and juice concentration

Apple cubes were subjected to vacuum impregnation using grape juice concentrate. The effect of pressure reduction (VP = 100–500 mmHg), immersion time (t = 10–30 min), and concentration of grape juice (C = 40–60°Brix) on impregnation parameters were evaluated using response surface methodology. Second-order polynomial equations were developed (R² > 0.895) to describe the behavior of water loss, total soluble solids, L*, a*, Hue, total color difference, the color of impregnated/treated areas (A_U/A_OP), antioxidant activity, total monomeric anthocyanin, and dimensionless volume (V/Vo) in the impregnated product. VP had a significant (p ≤ 0.05) effect on mass transfer parameters, color parameters, A_U/A_OP, and bioactive compounds. However, at 60°Brix and 500 mmHg, the lower V/Vo values were reached due to cell disruption. Therefore, it is recommended to use a VP = 500 mmHg and t less than 20 min to significantly impregnate compounds and obtain a product without considerable morphometric modification.     

苹果汁掺假(梨汁)的研究

从相同稀释倍数下的梨汁以不同体积掺入苹果汁后的pH变化,295nm处的吸光度的变化,总糖和还原糖的变化,旋光度的变化以及糖的薄层层析和感官评定等6个方面进行了探讨.结果表明：苹果汁掺入一定量的梨汁后的pH、295nm处的吸光度、总糖和还原糖及旋光度这4个方面的变化幅度较大,可以作为判断苹果汁中是否掺入梨汁的检测依据.     

〈秋季养生饮料篇〉香蕉汁

关键字：口味独特 香蕉口味甘美．但若做成饮料实属不易。这是因为香蕉本身无法榨取,只有添加其它液体调配而成。目前市面上所见届多的是香蕉口味的牛奶饮品,但事实上,香蕉饮料也有果汁饮料了。     

Portable, low-cost equipment for small-scale fruit juice processing

Simple, low-cost portable equipment to extract citrus juice, and pasteurize it and other fruit juices by passing through a coil of stainless steel tube in boiling water was designed, constructed and tested. Temperature reached was varied by altering the hydrostatic feed height, and the product was directly hot-bottled and capped. Pasteurization was microbiologically effective, and had little effect on ascorbic acid, furfural and colour of freshly prepared pineapple orange, Valencia orange and apple juices, and an orange squash drink, and only the expected changes occurred on storage at 21°C for periods up to 6 months, although with no indication of microbial activity. Taste panel ratings showed a loss of liking for treated orange juice, but not for apple. The equipment is suitable for improved utilization of crops by community technology in less-developed areas.     

Detection of fruit juice adulteration in apple and pear juice

A method has been developed to detect the adulteration of pear juice with apples and apple juice with pears. In different varieties of apples and pears and in several commercial juices the flavonoids were examined by HPLC with respect to their quality and quantity. The chalcones phloretin glucoside and phloretin xyloglucoside are typical compounds found in apples (detection limit 7 ng). They are suitable indicators for detecting adulteration of pear juice with apples. Isohamnetin glucoside cannot be detected in apples (detection limit 10 ng), but can be used to detect pears in apple juice. The extract or juice was purified with the aid of a polyamide column. The evaporated eluate of methanol was analysed by HPLC (gradient: acetonitrile/1% acetic acid). An RP-18 column and a UV-detector were used. Additionally, the UV spectra of the compounds indicating an adulteration were recorded by a diode array detector.     

Changes in orange juice color by addition of mandarin juice

The most natural way of improving the color of orange juices is by adding other juices, which provide a more intense coloration. The US legislation allows the addition of up to 10% of mandarin juice to the orange juice to improve its color. The first objective of this study was to compare the color characteristics of juices from 11 mandarin cultivars, currently being grown in Spain. Experimental results proved that only the green-red coordinate, a*, of the orange juices can be improved by adding mandarin juice. The mandarin cultivar that provided a juice with the highest values of a* was Clemenules. Once this selection was made, the effects of adding mandarin juice at different ratios, up to 10%, on the color characteristics of the orange juice were studied. Values of the a* coordinate went from 5.50 for the pure orange juice up to 6.29 for the mixture of 90% orange juice plus 10% of mandarin juice. Finally, hedonic tests proved that regular juice consumers preferred the color of mandarin juice to that of orange juice and that they liked better the color of the juice mixture containing 10% mandarin juice than that containing 3% mandarin juice.     

荔枝果汁及其果汁饮料的研制

研究了荔枝汁及荔枝汁饮料的工艺过程和产品的质量指标．同时也研究了影响荔枝汁稳定的因素以及在室温贮藏过程中护色剂对荔枝汁色泽变化的影响．     

消费观念:制约果汁业发展的瓶颈——访北京汇源饮料食品集团总裁朱新礼

<正> 对刚刚跨入21世纪的中国食品工业界来说,汇源老总朱新礼无疑是一颗引人注目的新星。他艰苦创业,10年拼搏,在取得骄人业绩后,却宁愿放弃公司董事长的位置,与屯河合作,可谓惊人之举。当时记者就曾在《中国食品工业》2002年第八期撰文介绍:尽管有很多人都不看好汇源跟新疆屯河之间的合作,认为朱新     

Phenolics from purple grape, apple, purple grape juice and apple juice prevent early atherosclerosis induced by an atherogenic diet in hamsters

Knowledge of the effects of processing on the antioxidant properties of fruits is limited. We investigated the processing of apple (A) and purple grape (PG) and their juices (AJ and PGJ) in hypercholesterolemic hamsters. Five groups of eight hamsters each were fed an atherogenic diet for 12 wk. They received daily by gavage either 7.14 mL/(kg x day) of mashed A or PG, or the same volume of AJ or PGJ, or water as control. Plasma cholesterol, non-HDL cholesterol, liver superoxide dismutase and glutathione peroxidase activities, and thiobarbituric acid reactive substances were efficiently reduced by the fruits and their juices compared with controls, whereas plasma antioxidant capacity was increased and aortic fatty streak area was decreased from 48 to 93%. For each of these parameters, the efficacy was PGJ > PG > AJ > A. The results show for the first time that long-term consumption of antioxidants supplied by apple and purple grape, especially phenolic compounds, prevents the development of atherosclerosis in hamsters, and that processing can have a major impact on the potential health benefits of a product. The underlying mechanism is related mainly to increased antioxidant status and improved serum lipid profile.     

Effect of pH,aeration and feeding non‐sterilized agave juice in a continuous agave juice fermentation

BACKGROUND: Continuous cultures have been used since the 1950s in beer and wine fermentations due to their higher productivities compared to traditional batch systems; nevertheless, the tequila industry has not taken advantage of the possible improvements that continuous fermentations could offer. In this work, the effect of pH, aeration and feeding of non‐sterilized medium, on the fermentative capability of two Saccharomyces cerevisiae strains (S1 and S2) cultured in continuous fermentation, using agave juice as the fermentation medium, were studied. RESULTS: In continuous cultures, the control of the medium pH (set point at 4) did not have a significant effect on fermentation efficiency compared to fermentations in which the pH was not controlled (pH 2.5 ± 0.3). Conversely, aeration of the cultures of both strains improved biomass production and consumption of reducing sugars and ammonium. The aeration also significantly augmented ethanol production only for S1 cultures (P < 0.05). Furthermore, the feeding of medium, either sterilized or not, did not show significant differences on the production of ethanol for S1 cultures. Higher concentrations of acetoin, succinic acid and diacetyl were found in the cultures fed with non‐sterilized medium. CONCLUSIONS: Compared to S2, S1 has a better fermentative performance in continuous non‐sterilized medium fermentations. Not controlling the pH during the cultures could prevent the possibility of microbial contamination as a result of the extreme medium acidity (pH 2.5 ± 0.3). This work showed the possibility of scaling up agave juice continuous fermentation feeding non‐sterilized medium with no control of pH. Copyright © 2010 Society of Chemical Industry     

〈秋季养生饮料篇〉厚福牌莲藕汁

关键字：多口味 无沉淀 莲藕的深加工,一般多是藕粉或者成菜等,如今开发藕汁．可谓是创新发展,而生产藕汁的厚福牌企业莲藕汁是以新鲜莲藕为原料,经过现代科学技术加工而成的新型果蔬饮料,藕香浓郁,甘甜爽口。     

〈秋季养生饮料篇〉乐天梨汁

“饮料市场风云变幻，让经销商与消费者不断尝鲜必然是好事，但没有一个产品能稳固它的市场。本期流行前沿对几款饮料进行点评，是看中了他们其中的亮点与不足，希望能与更多企业共勉。除了产品自身的优势，产品的卖点也需要企业在扩大自己的市场时不断宣传。”     

Clarification, preservation, and shelf life evaluation of cashew apple juice

Cashew apples are tropical fruits rich in sugars, minerals, and vitamin C. In spite of having high nutritional value, neither the fresh cashew apples nor the juice is consumed due to astringency. In the present investigation an attempt was made to reduce the astringency without affecting the nutrient quality of the juice. The clarifying agent, sago at a concentration of 2 g/L, has decreased the tannins by 42.85% but the respective sample’s visual clarity is only 94%. The same clarifying agent with the same concentration along with sterile filtration has decreased the tannins by 41.75% with improved visual clarity of 96%. This clarified juice sample was treated with chemical preservatives and the quality of the juice was assessed periodically up to 4 months. The shelf life of juice treated with citric acid and benzoic acid at 0.1 g/L each and stored at 4°C was prolonged up to 90 days.     

Effect of juice concentration on storage stability,betacyanin degradation kinetics,and sensory acceptance of red-fleshed dragon fruit (Hylocereus polyrhizus) juice

The aim of this study was to evaluate the effect of red-fleshed dragon fruit (Hylocereus polyrhizus) juice concentration on betacyanin degradation kinetics and sensory acceptance. The samples stored at 4°C were comparatively stable compared to 25°C in terms of betacyanin retention, and yeast and mold growth. The loss of betacyanin in red-fleshed dragon fruit juice and concentrate at 25, 37, and 45°C were of first-order reaction. The drink reconstituted from red-fleshed dragon fruit concentrate showed better acceptability in terms of sweetness, flavor, and overall acceptability. The current study demonstrated improved betacyanin retention and sensory acceptance of red-fleshed dragon fruit juice via juice concentration.     

Rheological behaviour of apple juice and pear juice and their concentrates

This paper reports the rheological behaviour of apple juice and pear juice. The effect of temperature on this behaviour for concentrated apple juice and pear juice of 71°Brix and 70°Brix, respectively, is examined and equations are given to describe the change in viscosity with temperature within the temperature range 5–60°C. The rheology of apple juice and pear juice of different soluble solids concentrations at 25°C is likewise reported with equations to relate the change in viscosity with concentration within the concentration range studied. In all these cases these juices are Newtonian in behaviour.     

特色蟠桃西瓜苹果醋饮料的研究

介绍了苹果醋的酿制方法及最佳工艺条件,并以苹果醋为酸味剂,辅以蟠桃汁、西瓜汁、苹果汁、蜂蜜等,研制出集营养、保健、风味于一体的果醋果汁饮料.     

Clarification of passion fruit juice by microfiltration: Analyses of operating parameters,study of membrane fouling and juice quality

In this study, the performance of two membranes were compared – tubular ceramic and hollow fiber poly(imide) – under transmembrane pressure of 0.5 and 1 bar, for the clarification of passion fruit pulp pre-treated by centrifugation and enzymatic treatment at the concentrations of 150 and 300 ppm. Nutritional and sensorial qualities of the clarified juice obtained were evaluated. Thus, it was possible to observe that the most adequate condition for the clarification of passion fruit pulp was with enzymatic treatment at 150 ppm and its posterior microfiltration at the ceramic tubular membrane of 0.3 μm with transmembrane pressure of 0.5 bar. The fouling mechanism was identified by estimation of model parameters according to a nonlinear regression by Bayesian inference. Analysis of the fouling mechanism results revealed that hollow fiber membrane is controlled by a cake filtration mechanism, and internal pore blocking fouling mechanism controls ceramic tubular membrane.     

鲜榨苹果汁与浓缩苹果汁酿酒特性的比较

以苹果鲜榨汁和浓缩汁为原料,分别通过添加蔗糖和稀释的方式使发酵起始糖度为200g／L进行酒精发酵。对发酵产品的常规理化指标和总酚,总类黄酮以及黄烷醇含量进行测定,并对发酵产品进行感官鉴评。实验结果表明：稀释浓缩汁和鲜榨果汁酒样总酸含量分别为2．6g／L和3．2g/L。鲜榨果汁酒样总酚含量、总类黄酮以及黄烷醇含量均高于稀释浓缩汁酒样。两种酒各具特色,鲜榨汁酒样果香浓郁,稀释浓缩汁酒样酒香醇厚。