DEVELOPMENT OF ACIDIFICATION PROCESSING TECHNOLOGY TO IMPROVE COLOR AND REDUCE THERMOPHILIC SPOILAGE OF CANNED MUSHROOMS

An acid vacuum hydration process followed by canning in EDTA/brine was evaluated for improving color and reducing thermophilic spoilage of canned mushrooms. Blanching in citric, fumaric or phosphoric acids and vacuum hydration in 0.05 M citric acid (pH 3.5) improved the color of the canned product significantly over untreated controls. EDTA (500 ppm) in the canning brine further improved color. Application of the citric acid vacuum hydration process to 227 kg quantities of fresh mushroom tissue in a commercial cannery resulted in no loss in canned product yield, significantly improved product color, greatly minimized thermophilic spoilage and did not significantly influence flavor and texture.     

绿豆蜂蜜果冻的研制

以绿豆和蜂蜜为主要原料,辅以白砂糖、柠檬酸、食用胶凝剂等研制出绿豆蜂蜜果冻。结果表明:当白砂糖10％、蜂蜜9％、卡拉胶1％、柠檬酸量0．4％时,生产出的果冻具有绿豆和蜂蜜的风味,感官状态良好。     

绿豆乳饮料加工工艺的研究

以绿豆、鲜乳为主要原料研制绿豆乳饮料。根据绿豆汁与鲜乳、白砂糖、柠檬酸的不同配比,从风味、口感、色泽及组织状态等几个方面进行感官评定,得出绿豆乳饮料最佳配方为:绿豆汁30ml、鲜乳20ml、白砂糖4g、柠檬酸0.05g。绿豆乳饮料加工中,选用0.2%的羧甲基纤维素钠(CMC-Na)作为稳定剂。该饮料呈淡绿色,酸甜可口,并带有一定的绿豆清香味,无杂质,稳定性好。     

Spoilage of an acid food product by Clostridium perfringens, C. barati and C. butyricum

Spoilage of canned pasteurized brined mung bean sprouts, acidified with citric acid to pH 4.0-4.5, was found to be caused by acid tolerant Clostridium spp. including the species barati, perfringens and butyricum. The pH limit for growth in the brine used were estimated 3.7, 3.7 and 4.0 respectively. Some of the isolated C. perfringens strains produced enterotoxins in sporulation media. The spores of the isolated anaerobes appeared to originate from mung beans, but C. barati and C. perfringens strains freshly isolated from dry beans, were unable to grow in acidified brine. During germination and sprouting of mung beans, the oxygen concentration decreased, while carbon dioxide concentration increased considerably, due to respiration of the sprouts and actively growing Enterobacteriaceae and lactobacilli. It was assumed that this allowed C. barati and C. perfringens strains to grow and acquire the observed unusual acid tolerance. After increasing aerobicity during sprouting, no growth of Clostridium spp. was observed, substantiating the assumption.     

Quality of canned mushrooms acidified with glucono-δ-lactone

Summary The effect of sterilisation conditions (116 °C, 54 min; 121 °C, 24 min and 126 °C, 8 min) and acidification with glucono-δ-lactone as compared with other acids (citric, ascorbic and EDTA) on the yield and quality (colour, texture and taste) of canned whole mushrooms, has been studied using previously refrigerated raw material (1.5 or 2.5 days at 2 °C). Colour measurement of canned mushrooms by the determination of the L* parameter of ten mushroom pilei probed to be the most suitable method, among those studied, shown the greater F parameter in a variance analysis. Yield was higher when the raw material was stored under refrigeration for longer. Yield, texture and colour improved with the Highest Temperature and Shortest Time process (126 °C, 8 min). Glucono-δ-lactone appears to be a more suitable acidulant than citric acid as it provides equal colour, texture and yield without conferring as acid a taste as citric or an extraneous flavour.     

Dynamic changes in phytochemical composition and antioxidant capacity in green and black mung bean (Vigna radiata) sprouts

The mung bean (Vigna radiata) sprout is a popular fresh vegetable in many parts of the world. In this study, the dynamic change of ascorbic acid, phenolic composition and antioxidant capacity were evaluated in green and black mung bean sprouts. Germination increased ascorbic acid, total phenolic content and antioxidant capacity in both mung beans. The green mung bean sprout generally had higher ascorbic acid, total phenolic content and antioxidant capacity than the black mung bean sprout. Most phenolic compounds, such as caffeic acid, catechin, ferulic acid, gallic acid and rutin, were found to gradually increase after germination. Therefore, mung bean sprouts, especially green mung bean sprout possessing high level of antioxidant phytochemicals, can be valuable functional vegetables and good sources of natural antioxidants.     

Effects of chemical acidification and microbial fermentation on the rheological properties of meat products

The gelation patterns of meat batters acidified with lactic acid bacteria (LAB) fermentation, liquid lactic acid, encapsulated lactic, citric and gluconic acids were studied. LAB provided slow (overnight) acidification that resulted in a significantly higher pre-cooking modulus of rigidity (G') value compared to all treatments, including a non-acidified control. The LAB heat-gelation pattern was also different from all other treatments. Liquid lactic acid caused an immediate pH reduction (from 5.6 to 4.6), crumbly texture, moisture release, and an initial higher G' value compared to the control, but lower than the LAB. The hydrogenated oil encapsulated acids, designed to release acid at 51-55°C, did not produce crumbly texture or moisture release. Encapsulated lactic acid showed an increase in the initial G', probably because of limited pre-cooking acid release. However, citric and gluconic acids showed no such effect. During cooling, LAB treatment showed the lowest G' value curve, followed by the control, liquid lactic acid, and the encapsulated acids.     

绿豆魔芋果冻的研制

以绿豆和魔芋精粉为主要原料,辅以白砂糖、食用胶凝剂和柠檬酸等研制出果冻。通过实验确定产品的最佳生产配方为:绿豆汁4.8%、魔芋精粉0.4%、琼脂0.1%、白砂糖15%、柠檬酸0.1%,生产产品香味特别,风味爽口,营养全面且具有较好保健功能的绿豆魔芋果冻。     

The effect of processing on the texture of canned mung bean (Phaseolus aureus) shoots

The effect of various processing regimes on the pectic substances and the final texture of canned mung bean shoots has been studied. A blanching temperature of 75°C for 30 s was optimal in activating the native pectinesterase of the shoots and a holding temperature of 55°C for an optimal 30 min led to maximal deesterification of pectin. This treatment resulted in a canned product that was superior to a sample blanched at 100°C.; the addition of calcium ions did not improve the product.     

绿豆衣清爽饮料护色工艺优化

将绿豆芽生产中\     

双歧绿豆乳果冻的研制

实验以绿豆、魔芋粉、卡拉胶、脱脂奶粉为主要原料,采用正交试验方法探讨双歧绿豆乳果冻的最佳配方。结果表明:双歧绿豆乳果冻的最佳配方为:奶粉质量分数为2%,凝胶剂质量分数为0.8%(魔芋粉与卡拉胶两者的配比为7∶3),总糖质量分数为14%,柠檬酸质量分数为0.12%。利用该配方生产的双歧绿豆乳果冻,具有双歧乳独有的功效和香味,口感爽滑,酸甜适度,富有弹性,冻体完整,是一种新型发酵型天然营养果冻。     

风味蟹肉软罐头护色工艺优化

以小规格蟹的蟹肉为原料,研究了风味蟹肉软罐头制备过程中的护色工艺优化.以L*值、b*值及相对褐变程度作为评价指标,通过单因素试验和正交试验设计研究4种护色剂(柠檬酸、D-异抗坏血酸钠、抗坏血酸和植酸)的浓度、护色时间对风味蟹肉高温灭菌后色泽的影响.最终得到风味蟹肉的最佳护色工艺为:0.4％柠檬酸和0.2％D-异抗坏血酸...     

CALCIUM, PHOSPHOROUS AND NITROGENOUS COMPOUND CONTENTS OF CHICKEN BROTH FROM BROILER BREAST FRAMES AS AFFECTED BY VARIOUS ACIDULANTS

The effect of acidulants on the total nitrogen, pH, gelatin, calcium, and phosphorous contents of chicken broth was investigated. Acidulants used included: ascorbic, acetic, citric, lactic, and phosphoric acids. All acidulants at a 0.50% level increased (P<0.05) the calcium and phosphorous contents of the broth prepared from broiler breast frames. The highest calcium and phosphorous contents were produced in chicken broths prepared with 0.50% phosphoric acid, followed by citric, lactic, acetic and ascorbic acids. Phosphoric acid-treated broth showed the highest nitrogen and gelatin contents, followed by lactic, citric, acetic, and ascorbic acids, in that order. As phosphoric acid concentration increased from 0 to 0.05%, the total nitrogen and gelatin contents of the broth decreased. However, phosphoric acid, at a concentration as low as 0.025%, increased (P<0.05) calcium and phosphorous extraction. Results indicated that acidulants could be used for the processing of high calcium and phosphorous chicken broth from broiler breast frames.     

外源锌浸种处理对绿豆芽生长和营养品质的影响

为开发一种富锌食品,采用不同浓度硫酸锌(0²00 mg Zn²⁺/L)溶液浸泡绿豆种子8 h并水培96 h后,研究外源锌浸种对绿豆芽生长指标、主要营养成分、植酸及锌积累的影响。结果显示:25⁷5 mg Zn²⁺/L锌溶液浸种可以提高绿豆芽下胚轴长、根长、生物产量和主要营养成分的含量,其中以50 mg Zn²⁺/L最显著,该浓度锌溶液浸种后培育的绿豆芽中游离氨基酸总量、维生素C、可溶性蛋白、可溶性糖的含量分别达到8.96 mg/g、23.76 mg/100 g、56.82 mg/g、6.62 mg/g;在实验考察的浓度范围内,绿豆芽中锌含量增加了90.9%⁶17.0%;萌发和外源锌浸种分别使植酸含量降低了61.5%和62.0%,但两组间无显著差异（p>0.05）。本研究表明,适当浓度的外源锌(<75 mg Zn²⁺/L)浸种处理对绿豆的萌发和生长是有利的,不仅能增加微量元素锌的营养价值,同时又能提高绿豆芽的营养品质。      

Effect of plasma-activated water on microbial quality and physicochemical characteristics of mung bean sprouts

The efficacy of nonthermal plasma-activated water (PAW) in the decontamination of mung bean sprouts was evaluated in this work. After being treated with PAW for 30 min, the populations of total aerobic bacteria and total yeasts and moulds on mung bean sprouts were decreased by 2.32- and 2.84- log₁₀ CFU/g, respectively. The PAW treatment had no significant effect on the antioxidant potential of mung bean sprouts as shown by using 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH•) scavenging activity assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) method, and ferric reducing antioxidant power (FRAP) assay (p > 0.05). Additionally, the PAW treatment caused no significant changes in the total phenolic and flavonoid contents, nor the sensory characteristics of mung bean sprouts (p > 0.05). Reactive species such as nitrates, nitrites, and H₂O₂ were generated in PAW, which presumably contributed to the disinfection efficacy of PAW. These data show that PAW can be used as a promising nonthermal technology for the control of microbial contamination in sprouts.Industrial relevanceEdible sprouts are common food ingredients across the world. However, sprouts can be contaminated by pathogenic microorganisms, which may result in health risks to humans. Recently, PAW has been shown to be a safe and effective method for food surface sanitation. However, the application of PAW in the microbial control for sprouts is less investigated. In this study, the influences of PAW on the microbial load, chemical and sensory quality of mung bean sprouts were investigated for the first time. The results showed that PAW could effectively inactivate bacteria and yeasts and moulds on mung bean sprouts without resulting in significant changes in the antioxidant capacities, total phenolic and flavonoid contents, and sensory characteristics of mung bean sprouts. These data indicated that PAW can be used as a promising nonthermal technology for reducing microbial populations on sprouts.     

Inhibition of Browning of Harvested Head Lettuce

Treatments to control browning of lettuce stem discs (cv Iceberg) were evaluated by measuring changes in the L*, a* and b* parameters as well as Hue angle values. Cysteine, resorcinol, EDTA and citric acid prevented discoloration. Different concentrations of organic acids (citric, acetic and gluconic), vinegar and lemon juice were also tested. The best results were obtained when the discs were treated with 10 mL/L and 50 mL/L acetic acid solutions and vinegar. These treatments were then applied to head lettuces and browning was measured during 7 days storage at 2°C plus an additional commercialization of 3 days at 13°C. Vinegar and 50 mL/L acetic acid solution inhibited browning on lettuce stem cuttings and could be used to prevent lettuce butt discoloration during cold storage and commercial handling.     

Combined efficacy of nisin and pediocin with sodium lactate, citric acid, phytic acid, and potassium sorbate and EDTA in reducing the Listeria monocytogenes population of inoculated fresh-cut produce

The inability of chlorine to completely inactivate human bacterial pathogens on whole and fresh-cut produce suggests a need for other antimicrobial washing treatments. Nisin (50 microg/ml) and pediocin (100 AU/ml) individually or in combination with sodium lactate (2%), potassium sorbate (0.02%), phytic acid (0.02%), and citric acid (10 mM) were tested as possible sanitizer treatments for reducing the population of Listeria monocytogenes on cabbage, broccoli, and mung bean sprouts. Cabbage, broccoli, and mung bean sprouts were inoculated with a five-strain cocktail of L. monocytogenes at 4.61, 4.34, and 4.67 log CFU/g, respectively. Inoculated produce was left at room temperature (25 degrees C) for up to 4 h before antimicrobial treatment. Washing treatments were applied to inoculated produce for 1 min, and surviving bacterial populations were determined. When tested alone, all compounds resulted in 2.20- to 4.35-log reductions of L. monocytogenes on mung bean, cabbage, and broccoli, respectively. The combination treatments nisin-phytic acid and nisin-pediocin-phytic acid caused significant (P < 0.05) reductions of L. monocytogenes on cabbage and broccoli but not on mung bean sprouts. Pediocin treatment alone or in combination with any of the organic acid tested was more effective in reducing L. monocytogenes populations than the nisin treatment alone. Although none of the combination treatments completely eliminated the pathogen on the produce, the results suggest that some of the treatments evaluated in this study can be used to improve the microbial safety of fresh-cut cabbage, broccoli, and mung bean sprouts.     

复合保鲜剂对鲜切莲藕贮期品质的影响

以二氧化氯预处理后的鲜切莲藕为材料,采用柠檬酸、乙二胺四乙酸二钠、L-半胱氨酸、抗坏血酸对藕片进行复合处理,通过测定藕片褐变度、可溶性固形物、感官品质等指标。结果表明:复合保鲜剂最佳组合为0.8%柠檬酸、0.25%乙二胺四乙酸二钠、0.2%L-半胱氨酸、0.35%抗坏血酸,可有效抑制莲藕褐变,提高贮藏期间产品品质。     

Acidification Requirements for Home Canned Combinations of Tomatoes and Low-Acid Ingredients

Alternative methods of estimating acidification requirements for home canned high-acid foods comprising combinations of tomatoes with low-acid ingredients were compared with forty representative products. Acidification estimates were based on recipe specifications, titration data, predictions made with a regression equation derived from a quadratic model, and predictions derived from a worst case analysis of the model. The last method resulted in satisfactory pH reductions (0.2-0.3 unit) even with products having pH values close to 4.6. Acidification recommendations based on the worst case analysis are given for eight categories of high-acid combination products.     

聊城市市售豆芽菜中5种植物生长调节剂残留调查分析

目的 分析聊城市东昌府区市售绿豆芽和黄豆芽中6-苄基腺嘌呤、4-氯苯氧乙酸、2,4-二氯苯氧乙酸、吲哚乙酸、吲哚丁酸的残留情况。方法 样品采用QuEChERs方法提取, 用含有0.1%甲酸的5 mmol/L乙酸铵水(A)和甲醇(B)作为流动相进行梯度洗脱, 质谱采用多反应监测-信息依赖性采集-增强子离子扫描模式(multiple reaction monitoring-information dependent acquisition-enhanced product ion, MRM-IDA-EPI), 同时得到的子离子谱图用于谱图库检索进行定性确证分析。结果 绿豆芽和黄豆芽中均存在植物生长调节剂残留, 在所检测的20份样品中, 10份检出6-苄基腺嘌呤, 11份检出4-氯苯氧乙酸, 20份检出吲哚乙酸, 其他两项均未检出。阳性样品的谱图匹配度均高于70%。结论 市售豆芽中植物生长调节剂的滥用依然存在, 必须持续监测和控制豆芽中植物生长调节剂的残留, 谨防滥用植物生长调节剂给消费者健康带来的风险。