响应面法优化莲藕果蔬汁加工工艺

为了得到营养又安全的复合果蔬汁饮料,此试验以新鲜的莲藕为原料,探讨了复合果蔬汁饮料的制作的最优工艺条件。通过单因素试验及响应面法得到最优组合,即同时添加的葡萄浓缩汁浓度20%、樱桃浓缩汁浓度14%、黄瓜浓缩汁浓度14%、白砂糖添加量31 g,此时感官评分为9.56分,产品最容易被人接受。除此之外,还得到黄瓜浓缩汁的浓度对莲藕果蔬汁的感官评价影响最大。     

苹果混合汁配比的研究

以黄元帅、红秦和红富士3种苹果为试材,运用D-最优混合设计（Mixture-D-Optimal design）,以糖酸比为响应值,对3种苹果原汁进行不同配比的复合调配,并应用模糊数学对复合苹果汁进行了感官评定。根据复合苹果汁的风味．确定了苹果复合汁最优配方为：黄元帅原汁50％、红秦原汁50％,成品的糖酸比为30．77。     

猕猴桃-紫甘蓝-苹果复合果蔬汁饮料的研制

以猕猴桃、紫甘蓝和苹果为主要原料,并加入白砂糖和柠檬酸研制具有最佳配方和风味的果蔬汁饮料。经查阅文献及资料可知,现在我国果蔬汁饮料行业发展迅速,前景可观。而猕猴桃、紫甘蓝、苹果中所含营养素丰富,混合后可达到营养素互补的功效。以感官评定为评价指标,经过单因素和正交试验,确定出复合果蔬汁的最佳配方,并测定复合饮料的营养价值和微生物指标。结果表明:复合果蔬汁饮料的最佳原料比为4∶9∶4,白砂糖8%,柠檬酸0.3%。用此配方研制出的复合果蔬汁饮料口感清爽、酸甜适口,色泽诱人,营养健康。     

均质压力和稳定剂对复合果蔬汁体态稳定性研究

以番茄、草莓、胡萝卜和葡萄原汁制成的混浊型复合果蔬汁为试材,进行不同均质压力、稳定剂组合试验,考察复合果蔬汁的体态稳定性。结果表明:均质压力为30MPa时,复合果蔬汁的浊度和不稳定性悬浮物最小;复合稳定剂组合为黄原胶0.15%+CMC0.05%+果胶0.05%时其稳定效果最好。     

植物乳杆菌发酵不同果蔬汁的品质分析

乳酸菌发酵果蔬汁是最受关注的益生菌饮品之一,不同果蔬汁经乳酸菌发酵后其抗氧化性等品质变化不一,影响着消费者的选择。用植物乳杆菌分别发酵脐橙、蜜柚、芒果、苹果、梨、西瓜、番茄和青瓜。各果蔬汁经48 h发酵后,活菌数均能达9.0 lg (CFU/mL)以上;苹果、番茄、脐橙、蜜梨的DPPH自由基清除率基本持平,蜜柚、芒果和西瓜的显著上升,且果蔬汁发酵后的总酚含量和DPPH自由基清除率两者呈极显著的正相关关系(p0.01);除青瓜汁外,其余果蔬汁的类超氧化物歧化酶(SOD-like)活性增加14%～55%不等,其中芒果、蜜柚的增幅最大。在感官上,乳酸菌发酵能提升果蔬汁风味、保护色泽,脐橙、蜜柚、芒果、苹果和梨发酵后感官总体接受度提高。发酵过程合成或释放的酚类及其他SOD-like成分,活菌数的增加及产酸都有利于果蔬汁的总酚含量及相关抗氧化性的保持及增加。     

大蒜复合保健饮料的研究

用大蒜、番茄、胡萝卜、苹果为原料制成复合保健饮料。对大蒜的除臭效果,果蔬汁所占的比例,对混合原汁、蔗糖、柠檬酸的用量以及制成品杀菌温度和时间等影响饮料风味的主要因素进行研究。结果表明,当苹果汁、番茄汁、胡萝卜汁、除臭大蒜汁的比例为15∶3∶2∶1,混合原汁用量为25%,蔗糖的浓度为6%,柠檬酸的浓度为0.14%,杀菌温度为90℃杀菌15s时,复合保健饮料的风味最佳。     

乳酸发酵复合果蔬汁配方的研制

以胡萝卜、苹果、番茄为复合果蔬汁原料,利用发酵酸乳的乳酸菌(保加利亚乳杆菌、嗜热链球菌)和发酵泡菜的乳酸菌(植物乳杆菌)混合作为发酵菌种,考察果蔬汁中添加葡萄糖、蔗糖、麦芽汁和大豆酶解蛋白对菌种的促生情况及复合果蔬汁的风味影响。最终确定了复合果蔬汁的最佳配比为:胡萝卜∶苹果∶番茄=50∶30∶20、葡萄糖3%、蔗糖8%、麦芽汁6%、大豆蛋白0.5%。调配好的复合果蔬汁灭菌条件为:温度95℃、时间10min。     

淮山药葡萄梨复合运动饮料的研制

以淮山药、葡萄、梨为原料,复配生产复合运动饮料,结果表明:当淮山药、葡萄、梨原汁比例为30:30:40时,产品的感官品质最优。通过正交试验确定了不同稳定剂的最优添加比例。当黄原胶、卡拉胶、羧甲基纤维素(CMC)的添加量分别为0.3%,0.2%,0.3%,产品的稳定性最好。     

运用Mix-D-optimal设计开发紫甘蓝花色苷抗氧化复合果蔬汁饮料

优化紫甘蓝花色苷复合果蔬汁饮料的配方,并测定其抗氧化性.运用Mixture-D-optimal设计,以糖酸比为响应值,在未添加其他添加剂的条件下,利用苹果汁、黄瓜原汁和紫甘蓝花色苷三种原汁自身的糖、酸及风味物质进行复合,形成酸甜适口、风味相容的粉色复合果蔬汁饮料.实验结果表明:紫甘蓝花色苷抗氧化复合果蔬汁饮料的最佳配方...     

复合芦笋汁加工工艺研究

以芦笋弃料(笋皮)为原料,经破碎、榨汁后,出汁率为52.5%,含可溶性固形物3.8%。将25%～40%的芦笋原汁与10%～25%苹果原汁复合时,可较好地掩盖芦笋皮带入的苦味,而芦笋特有的清香味不受影响。芦笋原汁35%、苹果原汁15%、白砂糖3%、柠檬酸0.15%、阿斯巴甜0.03%与清水组成复合芦笋汁具有浓郁的芦笋清香味,略带苹果香味,甜酸适口。     

DILUTION AND SOLIDS ADULTERATION OF APPLE JUICE

The adulteration of apple juice with pear juice and corn drived syrups has been practiced in many countries. The sorbitol/sucrose ratios and the sorbitol/total sugar ratios were determined for the juices of 14 apple varieties and 3 pear varieties. A multivariate normal test was applied to develop an equation for the detection of apple juice adulteration with sugar solutions or pear juice. Adulteration of apple juice with more than 10% sugar solution or pear juice were detectable with this method.     

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.     

Color Stability of Apple and Pear Juices Blended with Fruit Juices Containing Anthocyanins

Apple and pear juices blended with anthocyanin pigmented juices developed haze and color stability during commercial marketing. To determine factors contributing to these problems, juice from apple and d'Anjou pear (prepared from whole fruit) and‘Bartlett’pear (peels and cores) were blended with 5, 10, 20%‘Concord’grape,‘Bing’cherry, or red or black raspberry juice. During storage at 25°C for up to 48 wk, turbidity, polymeric color, and % color due to tannin increased, while anthocyanin concentration decreased. As % anthocyanin pigmented juice increased, turbidity and polymeric color increased and % color due to tannin decreased. Within a given base juice, turbidity was highly correlated with polymeric color (r = 0.78 to 0.97).     

草莓汁中糖酸组成分析及其在掺假鉴别中的应用

为了解草莓汁的糖酸组成特点并探索其在掺假鉴别中的应用,采用高效液相色谱法对10个品种草莓果汁中可溶性糖、有机酸组成与含量进行分析,结合化学计量学方法探索其在草莓汁掺假鉴别中的应用。结果表明,草莓汁中可溶性糖主要由蔗糖、葡萄糖和果糖组成,有机酸主要是柠檬酸和苹果酸。不同品种草莓果汁中各种可溶性糖和有机酸的含量存在较大差异,但葡萄糖与果糖的比值受品种影响较小,柠檬酸占检测到总有机酸含量的62.39%~82.73%。通过分析草莓原汁及其掺假样品中可溶性糖和有机酸组成,结合主成分分析和线性辨别分析等模式识别方法,可以实现对草莓果汁与掺加梨汁、苹果汁、杏汁和桃汁等掺假样品的区分,而且掺假量越大,区分效果越好。草莓果汁可溶性糖和有机酸组成特征结合化学计量学分析能够对掺假草莓果汁进行较好地区分,可用于草莓果汁掺假鉴定和质量控制。     

Singlet Oxygen Quenching Activities of Various Fruit and Vegetable Juices and Protective Effects of Apple and Pear Juices against Hematolysis and Protein Oxidation Induced by Methylene Blue Photosensitization

ABSTRACT:  Effects of various fruit and vegetable juices on rubrene oxidation induced by a chemical source of singlet oxygen in a microemulsion system have been studied. The singlet oxygen quenching activities of fruit and vegetable juices were greatly different with different juices. The apple and pear juices exhibited the highest antioxidative activity among the tested juices in singlet oxygen–induced rubrene oxidation, showing 56.69% and 59.34% inhibition, respectively. The grape, kumquat, red cabbage, and spinach juices also showed relatively strong antioxidative activity against singlet oxygen–induced rubrene oxidation. Lemon juice showed the least activity, resulting in 0.63% inhibition of rubrene oxidation. The singlet oxygen quenching activities of 1 mL of apple and pear juices were equivalent to 33.97 and 34.64 mg ascorbate, respectively. Singlet oxygen quenching activities of juices had very low correlation with both ABTS radical scavenging activity ( R ²= 0.11) and total phenolic contents ( R ² < 0.1). However, a high correlation ( R ²= 0.66) was found between the ABTS radical scavenging activities and total phenolic contents of juices. The apple and pear juices also significantly inhibited both erythrocyte lysis and protein oxidation induced by fluorescence light illumination in the presence of methylene blue. Electron spin resonance (ESR) spectroscopy data showed that the protective activities of these juices against biological damages induced by photodynamic ways were, to at least some extent, due to their singlet oxygen quenching abilities. This represents first report on the singlet oxygen quenching activities of the apple and pear juices, and their protective activities against photodynamically induced biological damages.     

Concentration of apple and pear juices in a multi-plate freeze concentrator

In this article we will examine the process for concentration of apple and pear juices as well as concentration of sugar solutions modelling pear juice (simulation fluid) using a descending film multi-plate freeze concentrator. It has been determined in advance the freezing point of those fluids in the working concentration and temperature intervals. In addition, different parameters were studied to allow tracking of the process of freeze concentration, such as ice accumulation, variation of the content of soluble solids in the solution and in the ice removed, ice production and energy consumption. The apple and pear juices tested showed similar behaviour, while the mixture of sugars used for simulation showed better behaviour, due perhaps to the absence of foam in the process and to the quicker formation of ice. It has been obtained concentrations of 30.2 and 30.8 °Bx with the apple and pear juices, respectively, and up to 32.7 °Bx with the simulation fluid.Industrial relevanceThe clarified juices usually are concentrated on an evaporation stage. In this stage the juice is subjected to high temperatures that cause undesirable reactions, such as non enzymatic browning and destruction of nutritive compounds. The freeze concentration is a technology that allows eliminating water from the juices at temperatures below the water’s freezing point, what allows obtaining products of better quality. In this work has been applied this technology to concentrate apple and pear juices, obtaining promissory results.     

果汁发酵生产细菌纤维素

为提高果汁发酵生产细菌纤维素的产量,开发特色纤维素功能性食品,以葡糖醋杆菌CGMCC 3917为实验菌种,以苹果汁和梨汁为发酵培养基生产细菌纤维素(BC),研究果汁用量和酵母膏添加量对细菌纤维素产量的影响,比较分析两种果汁生产的细菌纤维素在产量、结构和性质方面的差别。结果表明：梨汁发酵生产的细菌纤维素产量明显高于苹果汁,可达46.343g/100mL;其BC干膜复水率显著高于苹果汁,BC干膜的总糖含量稍高于苹果汁。两种果汁发酵生产的细菌纤维素在湿膜持水量及干膜的纤维素含量、蛋白质含量、脂肪含量以及微观结构上没有明显差异。     

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.     

Survival and growth of Enterobacter sakazakii on fresh-cut fruits and vegetables and in unpasteurized juices as affected by storage temperature

Enterobacter sakazakii is an emerging foodborne pathogen that has caused illnesses and deaths in infants and elderly immunocompromised adults. Outbreaks of E. sakazakii infection have been associated with infant formulas, but the documented presence of this pathogen in a wide variety of ready-to-eat foods, including lettuce and other raw vegetables, makes it important to learn more about its behavior in these environments. We investigated the survival and growth characteristics of E. sakazakii on fresh-cut apple, cantaloupe, strawberry, watermelon, cabbage, carrot, cucumber, lettuce, and tomato and in juices prepared from these fruits and vegetables. Produce and juices were inoculated with E. sakazakii at 2 to 3 log CFU/g and 1 to 2 log CFU/ml, respectively, and stored at 4, 12, or 25 degrees C. Populations either did not change or gradually decreased in fresh-cut produce and juices stored at 4 degrees C but grew at 12 degrees C on fresh-cut apple, cantaloupe, watermelon, cucumber, and tomato and in all juices except apple, strawberry, cabbage, and tomato juices. All fresh-cut fruits and vegetables except strawberry supported growth of E. sakazakii at 25 degrees C. Growth occurred in all juices except apple, strawberry, and cabbage juices, followed by decreases in population to < 1 CFU/ml after 48 to 72 h, which coincided with decreases in pH and an increase in the population of lactic acid bacteria. Increases in total counts occurred in all juices except strawberry juice stored at 25 degrees C and apple and strawberry juices stored at 12 degrees C. Total counts increased in cantaloupe, carrot, cucumber, and lettuce juices stored at 4 degrees C. Populations of molds and yeasts increased in apple and tomato juices stored at 25 degrees C but decreased to <1 CFU/ml in cabbage, lettuce, and cucumber juices. Further characterization of the behavior of E. sakazakii on fresh produce and in unpasteurized juice as affected by commercial packaging and handling practices is needed.     

茶多酚对新鲜原果汁保鲜效果的影响

将茶多酚添加到苹果汁、橙子汁和雪梨汁这三种常见果汁中,与山梨酸钾、苯甲酸钠比较研究其对新鲜原果汁的保鲜效果.结果表明,100mg/kg的茶多酚与500mg/kg的山梨酸钾防腐效果相当,对酵母菌、大肠杆菌和金黄色葡萄球菌均有明显抑制作用,能有效保持果汁原有风味并延长保鲜期7～10d.三种果汁中,茶多酚对苹果汁的保鲜效果最...