Development of low-alcohol isotonic beer by interrupted fermentation

Alcohol-free beer with isotonic properties is getting more popular and its production can be carried out by different production strategies; however, interrupted fermentation is still a challenge. Therefore, the objective of this study was to develop a low-alcohol isotonic beer (<0.5% v/v) by interrupted fermentation. Moreover, the major objective is to compare the developed product to commercial beverages (sports drinks, ‘Pilsen' regular beer, alcohol-free beers and low-alcohol isotonic beer). The beverages were evaluated based on pH, alcohol content (% v/v), total titratable acidity (mEq L⁻¹), osmolality (mOsmol kg⁻¹), bitterness International Bitterness Units, colour European Brewery Convention, total phenolic compounds (mg L⁻¹ gallic acid), reducing and total sugars (%) and Na and K contents (mg L⁻¹). The developed low-alcohol isotonic beer presented characteristics similar to sports drinks, with the advantage of being richer in phenolic compounds and suitable osmolality. Despite salts were added in its formulation, the grades attributed to all beers employed in the sensory evaluation, as well as the purchase intention did not present significant differences.     

冷饮厂制冷系统设计值得注意的几个问题

就制冷系统的设计,针对冷饮工厂的特点,提出了应该注意的几个问题。     

糖-蛋白质饮料对男力量运动员一次抗阻运动后部分血清指标的影响

为探讨糖-蛋白质补充对一次性抗阻运动恢复过程的影响.文中以18名男子力量项目运动员在一次抗阻运动前、运动中和运动后,分别摄入糖-高蛋白饮料(HP组=6人,糖:蛋白质=3∶1)、糖-低蛋白饮料(LP组=6人,糖∶蛋白质=6∶1)或纯糖对照饮料(C组=6人).在运动前、运动后即刻、运动后3h和运动后次日晨采集血样,测定血清肌酸激酶(CK)、天门冬氨酸转移酶(AST)、谷丙氨酸转移酶(ALT)、尿素(BU)以及睾酮(T)和皮质醇(Cor).研究结果表明:运动后3h和运动后次日晨C组CK水平显非常著高于HP组和LP组(P0.01,分别),运动后次日晨LP组CK水平显著高于HP组(P0.05);运动后3hC组ALT水平显著高于HP组和LP组(P0.05,分别);运动后即刻C组Cor水平显著低于HP组和LP组(P0.05,分别);各时间点T、AST及BU水平组间比较无差异性.摄入糖-蛋白质饮料能促进男性力量项目运动员抗阻运动后机体运动能力的恢复和提高.摄入糖-高比例蛋白质更有利于运动后疲劳的恢复和机体运动能力的提高.     

果味饮料企业标准制定的必要性和参考文本

本文介绍了我国软饮料及其在QS(质量安全)认证中的申证单元的分类,列举了我国已制定的相关软饮料国家标准和行业标准,分析了制定果味饮料企业标准的必要性,制定了一份果味饮料企业标准参考文本,希望对果味饮料国家标准和相关企业标准的制定具有一定的借鉴和促进作用.     

On the stabilization mechanism of Doogh (Iranian yoghurt drink) by gum tragacanth

Serum separation in Doogh, a favorite acidic dairy drink in the Middle East, is a major problem which happens due to low pH (≤4.00) and aggregation of caseins. Therefore, in the present study the influence of gum tragacanth (GT) and its soluble and insoluble fractions on prevention of serum separation as well as stabilization mechanisms were investigated using rheological, zeta potential and microscopic measurements. According to our findings, the soluble tragacanthin (T) and GT prevented serum separation at concentrations of 0.100 and 0.200%, respectively. Furthermore, the proper rheological model for control was Newtonian whereas for the others it was Power law. Based on viscoelastic experiments, Dooghs containing T and GT exhibited dominant viscose and elastic behaviors, respectively. In addition, the presence of T and GT changed the zeta potential values from positive to negative. It was elucidated that T adsorbs onto casein and induces stabilization via electrostatic and steric repulsions. Moreover, the insoluble bassorin (B) may assist stabilization by increasing the viscosity.     

Rapid quality control of spirit drinks and beer using multivariate data analysis of Fourier transform infrared spectra

Fourier Transform Infrared (FTIR) spectroscopy in combination with multivariate data analysis is introduced for the quality control and authenticity assessment of spirit drinks and beer in official food control. The spectra were measured using a FTIR interferometer, which is purpose-built for the analysis of alcoholic beverages and includes an injection unit for liquids with automatic thermostating of the sample. Only 2 min are required for FTIR measurement. For spirit drinks, no sample preparation is required at all. Carbon dioxide containing samples, such as beer were prepared by degassing.     

Corrosion of aluminium in soft drinks

The corrosion of aluminium (A1) in several brands of soft drinks (cola- and citrate-based drinks) has been studied, using an electrochemical method, namely potentiodynamic polarization. The results show that the corrosion of A1 in soft drinks is a very slow, time-dependent and complex process, strongly influenced by the passivation, complexation and adsorption processes. The corrosion of A1 in these drinks occurs principally due to the presence of acids: citric acid in citrate-based drinks and orthophosphoric acid in cola-based drinks. The corrosion rate of A1 rose with an increase in the acidity of soft drinks, i.e. with increase of the content of total acids. The corrosion rates are much higher in the cola-based drinks than those in citrate-based drinks, due to the facts that: (1) orthophosphoric acid is more corrosive to A1 than is citric acid, (2) a quite different passive oxide layer (with different properties) is formed on A1, depending on whether the drink is cola or citrate based. The method of potentiodynamic polarization was shown as being very suitable for the study of corrosion of A1 in soft drinks, especially if it is combined with some non-electrochemical method, e.g. graphite furnace atomic absorption spectrometry (GFAAS).     

含乳饮料中甘氨酸与谷氨酸及蛋白质的比例关系及其在造假乳饮料判定中的应用

为给违规添加甘氨酸掺杂造假含乳饮料的判定提供科学依据．测定了纯牛奶和含乳饮料中游离甘氨酸、谷氨酸的质量浓度和蛋白质的质量比，并对其相互比例关系进行研究。含乳饮料中的游离甘氨酸总量不应超过250mg／L，谷／甘比值不应低于3，游离甘氨酸占总蛋白的百分比应小于0．05％。综合样品中甘氨酸质量浓度、谷／甘氨酸比值、以及甘氨酸占总蛋白的百分比，可准确判断含乳饮料中是否人为添加外源性甘氨酸。     

Migration measurement and modelling from poly(ethylene terephthalate) (PET) into soft drinks and fruit juices in comparison with food simulants

Poly(ethylene terephthalate) (PET) bottles are widely used for beverages. Knowledge about the migration of organic compounds from the PET bottle wall into contact media is of interest especially when post-consumer recyclates are introduced into new PET bottles. Using migration theory, the migration of a compound can be calculated if the concentration in the bottle wall is known. On the other hand, for any given specific migration limit or maximum target concentration for organic chemical compounds in the bottled foodstuffs, the maximum allowable concentrations in the polymer C _P,0 can be calculated. Since a food simulant cannot exactly simulate the real migration into the foodstuff or beverages, a worse-case simulation behaviour is the intention. However, if the migration calculation should not be too overestimative, the polymer-specific kinetic parameter for migration modelling, the so-called A _P value, should be established appropriately. One objective of the study was the kinetic determination of the specific migration behaviour of low molecular weight compounds such as solvents with relatively high diffusion rates and, therefore, with high migration potential from the PET bottle wall into food simulants in comparison with real beverages. For this purpose, model contaminants were introduced into the bottle wall during pre-form production. The volatile compounds toluene and chlorobenzene were established at concentrations from about 20–30 mg kg^?1 to 300–350 mg kg^?1. Phenyl cyclohexane was present at concentrations of 35, 262 and 782 mg kg^?1, respectively. The low volatile compounds benzophenone and methyl stearate have bottle wall concentrations of about 100 mg kg^?1 in the low spiking level up to about 1000 mg kg^?1 in the highly spiked test bottle. From these experimental data, the polymer specific parameters (A _P values) from mathematical migration modelling were derived. The experimental determined diffusing coefficients were determined, calculated and compared with literature data and an A _P′ value of 1.0 was derived thereof for non-swelling food simulants like 3% acetic acid, 10% ethanol or iso-octane. For more swelling condition, e.g. 95% ethanol as food simulant, an A _P′ value of 3.1 seems to be suitable for migration calculation. In relation to PET recycling safety aspects, maximum concentrations in the bottle wall were established for migrants/contaminants with different molecular weights, which correspond with a migration limit of 10 μg kg^?1. From the experimental data obtained using food simulants and in comparison with beverages, the most appropriate food simulant for PET packed foods with a sufficient but not too overestimative worse-case character was found to be 50% ethanol. In addition, it can be shown that mass transport from PET is generally controlled by the very low diffusion in the polymer and, as a consequence, partitioning coefficients (K _P/F values) of migrants between the polymer material and the foodstuff do not influence the migration levels significantly. An important consequence is that migration levels from PET food-contact materials are largely independent from the nature of the packed food, which on the other hand simplifies exposure estimations from PET.     

大豆蛋白醒酒肽的研制

以低变性脱脂豆粕为原料,系统地研究了大豆蛋白醒酒肽的生产工艺流程、具体操作要点及产品质量标准.着重研究了蛋白酶水解、水解物脱苦、脱色及水解物脱盐、大豆蛋白醒酒肽饮料的调配等工序.