Production of Nonbitter, Desalted Milk Hydrolysate for Fortification of Soft Drinks and Fruit Juices

A simpler and less expensive process than the process of Helbig et al. (1980) for preparation of a nonbitter, desalted milk hydrolysate is presented. Skim milk was hydrolyzed with Alcalase (subtilisin Carlsberg) at 50°C in 3 hr. The resin in OH form was added to milk batchwise to simultaneously raise the pH to 8.5 for optimum proteolysis and exchange the anions in milk which contributed to saltiness. These modifications resulted in a shorter hydrolysis time and a more economical resin regeneration than those of the Helbig process. The dried milk hydrolysate was added to soft drinks and fruit juices at solids concentrations up to 10% (3% protein) without adverse effects on their taste, color, viscosity and clarity.     

超高压(UHP)技术在果汁灭菌中的应用

超高压处理技术被认为食品非热杀菌技术中最有潜力和发展前途的一种处理技术。我国的食品工业发展计划中超高压杀菌技术已经被列为重点开发的技术之一,超高压前几年一直处在小型试验研究阶段,如李里特与日本国际农林水产业研究中心的辰巳英三合作,对超高压下生产的豆腐凝胶进行了多方面的研究。     

生姜番茄草莓复合饮料的工艺研究

为了研究开发生姜果味饮料,本次试验通过单因素试验和正交试验相结合的方法,依据感官鉴定评价标准,邀请老师同学们对其进行评价打分,从而得出口感最好的1组配方作为姜汁番茄草莓果味饮料的最佳配方,即生姜汁添加量为8%、番茄汁添加量为25%、草莓汁添加量为35%、绵白糖添加量为10%。试验过程中加入复合稳定剂CMC 0.08%、黄原胶0.1%、β-环状糊精0.2%使得该果味饮料的稳定性最佳,从而得到均匀一致、口感细腻、酸甜可口的姜汁番茄草莓果味饮料。     

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).     

Sugar Analysis of Fruit Juices: Content and Method

The sugar contents of 186 samples of 11 different juices from a nation-wide sampling were determined by the use of a total sugar analyzer (TSA), a gas-liquid chromatograph (GLC) or both. Values for total sugar ranged from <3% in most tomato juices to >15% in some lemonades on a ready-to-serve basis. Agreement between the two methods was satisfactory.     

软饮料中糖的测定

应用高效液相色谱法测定了国外8种软饮料中的果糖、葡萄糖、蔗糖、麦芽糖和异麦芽糖的含量。测定时,将折光检测器与质量检测器串接联用,以折光检测器测定含量高的糖,以质量检测器测定含量低的糖。异麦芽糖的检出可以证实该软饮料以玉米糖浆作甜味剂。     

Alginate Texturization of Highly Acid Fruit Pulps and Juices

Apple pulp and reconstituted grapefruit juice were provided as texturized alginate gels at concentrations of 5–96%, after pH adjustment. The resulting products had appreciable mechanical integrity even at very high pulp or juice concentration. Their texture, judged by compressive strength, strain at failure, and deformability modulus was improved considerably by dipping in calcium lactate solution. The original pH of the fruit could be restored by a dip in a citric acid solution without adverse effects on texture.     

Enzymatic Clarification of Fruit Juices by Fungal Pectin Lyase

The activity of pectic enzymes was measured in culture filtrates of four selected fungal strains. Pectin lyase (PL) activity was produced by all fungi, but pectinesterase activity was not detected in culture filtrates of the strain Penicillium expansum F16. The use of crude enzymes resulted in good clarification of apple juice as evaluated by an increase in transmittance at 660 nm. PL activities were partially purified by dye-affinity chromatography on Blue Sepharose. The enzyme was bound to the column and eluted in a single peak, free of PE activity, and not coinciding with the major amount of protein. Apple, grape, and passion fruit juices were effectively clarified by these partially purified enzymes. Methanol content was determined by gas-liquid chromatography, being undetectable in the clarified juices. These pectic enzymes demonstrate potential for use in fruit juice processing.     

超滤对几种果蔬汁品质的影响

探讨了２种孔径（５０ＫＤ、１５０ＫＤ）的聚丙烯腈超滤膜对４种果蔬汁（甘蓝汁、黄瓜汁、萝卜汁和锦橙汁）品质的影响。结果表明：小分子的糖、酸、矿物质及维生素Ｃ的平均透过率超过９０％,２种膜间无显著性差异;大分子的蛋白质、果胶及脂溶性维生素Ｅ的平均透过率较低,２种膜间有显著性差异。超滤后的果蔬汁基本保持了固有风味并改善了某些不良风味。     

渗透蒸馏在果汁浓缩中的应用

渗透蒸馏又称为等温膜蒸馏,是一种新型的膜分离技术,一般在常压、室温下进行操作,它能生产出既保持原有芳香成分而又高度浓缩的果汁产品,该文对渗透蒸馏过程、特点,及其在果汁浓缩中的应用作了综述。     

我国果汁和果酒加工业发展现状及发展趋势

改革开放以来,特别是1984年国家彻底放开水果市场,价格随行就市,实行多渠道流通政策之后,我国水果生产得到空前发展。2001年水果总产量已超过6000万t,为世界第一大水果生产国,约占世界总产量的14％左右,在国内成为继粮食、蔬菜之后的第三大种植产品,也日益成为农民增收中的重要增长点。我国加入世界贸易组织(WTO)后,如何振兴我国果汁和果酒加工产业,进军国际市场,是摆在我们面前的紧迫任务。     

Inactivation of Spoiling Yeasts of Fruit Juices by Pulsed Ultrasound

This paper reports on the use of ultrasound (US) as a suitable strategy to control the growth of spoiling yeasts in fruit juices. In a first phase, US technique was tested towards Saccharomyces cerevisiae inoculated in different juices (strawberry, orange, apple, pineapple and red-fruits): the treatment was performed by modulating the level of the power (20–60 %), the duration of the treatment (2–6 min) and the pulse (2–6 s), according to a fractional design. Then, the best treatment was applied against some other spoiling yeasts (Pichia membranifaciens, Wickerhamomyces anomalus, Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Candida norvegica). Finally, a challenge test for a commercial beverage (red-fruit juice), inoculated with Z. bailii and containing a citrus extract, was conducted evaluating the effect of US on the sensory scores of the beverage. The results showed that the effect of US was mainly influenced by the power and the duration of the treatment; on the other hand, the effect of pulse was less significant and slight. The highest reduction of S. cerevisiae was found in the following combination of the design: power 60 %/time 4 min/pulse 2 s and power 60 %/time 6 min/pulse 6 s; this result was confirmed for the other spoiling yeasts. US and citrus extract could be combined to prolong the shelf life of the red-fruit juice and control the growth of Z. bailii. The two hurdles exerted a different role and acted in different times: US reduced the initial contamination, whilst citrus extract controlled the yeast within the storage.     

Enzymatic Clarification of Fruit Juices by Fungal Pectin Lyase

The activity of pectic enzymes was measured in culture filtrates of four selected fungal strains. Pectin lyase (PL) activity was produced by all fungi, but pectinesterase activity was not detected in culture filtrates of the strain Penicillium expansum F16. The use of crude enzymes resulted in good clarification of apple juice as evaluated by an increase in transmittance at 660 nm. PL activities were partially purified by dye-affinity chromatography on Blue Sepharose. The enzyme was bound to the column and eluted in a single peak, free of PE activity, and not coinciding with the major amount of protein. Apple, grape, and passion fruit juices were effectively clarified by these partially purified enzymes. Methanol content was determined by gas-liquid chromatography, being undetectable in the clarified juices. These pectic enzymes demonstrate potential for use in fruit juice processing.     

Analysis of Aliphatic Organic Acids in Commercial Fruit Juices by Capillary Electrophoresis with Indirect UV Detection: Application to Differentiation of Fruit Juices

A simple, cheap, and reliable capillary zone electrophoresis (CZE) method with indirect UV detection to determine the main organic acids in several fruit juices has been developed in this work. The parameters affecting CZE separation including the chromophore reagent (2,6-pyridinedicarboxylic acid, PDC) concentration and pH in background electrolyte (BGE), temperature, and applied voltage were studied. The analytical parameters of the method as linearity, precision, and detection and quantification limits were also investigated. The proposed method was applied to the evaluation of organic acid contents of commercial fruit juices from apple, grape, mandarin, orange, and pineapple and compared with the levels allowed by European legislation. A chemometric technique such as linear discriminant analysis (LDA) was also applied to differentiate fruit juices based on CZE data. This simple and reliable developed procedure allows a rapid control of adulteration of high-value commercial fruit juices, which constitutes an important tool for authenticity texting in food industries and regulatory agencies.     

PVC收缩套标在饮料市场上的作为

在今天的国内市场，作为一种二次包装材料，PVC收缩套标已经被广泛地采用，并越来越多地应用到饮料包装工业中。用PVC热收缩膜加工制作成的标签，印刷上丰富的文字和图案，收缩在容器的周身，组成了琳琅满目的商品中一道亮丽的风景线。     

Direct Determination of Saccharin and Acesulfame-K in Sweeteners and Fruit Juices Powders

A simple and rapid analytical procedure for determination of saccharin (SAC) and acesulfame-K (AC-K) based on UV-vis measurements and partial least squares (PLS) was proposed. Thus, an experimental design at levels 2 and 15 mg l⁻¹ for SAC and 2 and 20 mg l⁻¹ for AC-K was applied. Because real samples usually contain SAC and AC-K combined with aspartame (ASP), this interference was also included in the model. The procedure was successfully applied for SAC and AC-K simultaneous determination in sweeteners and fruit juice powders, without any separation step to remove ASP. The results were validated by using spiked samples, and the obtained recoveries were satisfactory.     

Pressure-Thermal Kinetics of Furan Formation in Selected Fruit and Vegetable Juices

Furan, a potential carcinogenic compound, can be formed in array of processed foods. The objective of this study was to conduct kinetic studies in pineapple juice and assess the interactive effects of pressure (0.1 to 600 MPa) and temperature (30 to 120 °C) on furan formation. Additional experiments were carried out in tomato, watermelon, cantaloupe, kale, and carrot juice to understand the influence of matrix and juice pH. Furan was monitored in raw (control) and processed samples by automated headspace gas chromatography mass spectrometry, and quantified by calibration curve method with d₄-furan as internal standard. The data were modeled using zero-, first-, and second-order equations. The zero-order rate constants (k _T,P ), activation energy (E _a ), and Gibbs free energy of activation (ΔG ^?) of furan formation in thermally processed (TP; 90–120 °C) pineapple juice were found to be 0.036–0.55 μg/kg/min, 98–114 kJ/mol, and 173.9–180.5 kJ/mol, respectively. Furan concentration was negligible and close to the detection limit (0.37 μg/kg) after pressure treatment (600 MPa at 30 °C) of juice samples. For similar process temperatures, the rate constants of pressure-assisted thermally processed (PATP; 600 MPa at 105 °C) pineapple juice were lower than that of TP samples. Furan formation was influenced by juice matrix and pH. On the other hand, PATP markedly suppressed furan (0.7 to 1.6 μg/kg) in these selected juices. In conclusion, furan formation increased with process temperature and treatment time, while pressure treatment at ambient temperature did not promote its production. Furan formation in TP fruit juices was also influenced by juice matrix and pH, but these were not the significant factors for PATP-treated juices.