Effects of water flow rate, salt concentration and water temperature on efficiency of an electrolyzed oxidizing water generator

A three-factor central composite design was adopted to investigate the effects of water flow rate, water temperature and salt concentration on electrolysis efficiency and separation efficiency of an electrolyzed oxidizing water generator. Results indicated that electric potential (7.9–15.7 V) and power consumption (16–120 W) of the electrolysis cell were not affected by water flow rate, water temperature or salt concentration in the feed solution. Electric current of the cells changed in between two levels (7.41 ± 0.1 and 7.68 ± 0.1 A) depending on water temperature and water flow rate. Electrolysis efficiency of the electrolysis cell, represented by the reduction ratio of chloride ions, varied in the range of 23–51%. Separation efficiency of the cation ion-exchange membrane, represented by the reduction ratio of sodium ions, varied in the range of 2–40%. Both efficiency rates were significantly reduced by increases in water flow rate and/or salt concentration in the feed solution.     

电解水杀菌技术及其应用

对电解水杀菌的设备,原理,影响电解水杀菌的因素及电解水在食品工业中的应用进行了综述。     

Effect of electrolyzed water treatments on the quality of hand- and machine-peeled yams (Dioscorea spp.) during cold storage

The effect of electrolyzed water treatment on the quality of yams by different peeling methods during cold storage was evaluated. The turbidity of the immersion solution increased with extensive storage time while total sugar of yams exhibited the tendency to lessen. The composition of free sugars ranged in the order of fructose>glucose>sucrose except for the samples processed by hand-peeling electrolyzed water and anhydrous storage. The machine peeling showed the suppression of microorganisms that was 1 log cycle lower than hand peeling except EW-2-S. In both hand- and machine-peeled treatments of immersion storage, the effectiveness of the suppression of microorganisms was in the order of 0.6% acetic acid (AA)>EW-1-S>EW-2-S. The results of sensory characteristics of hand-peeled yam were slightly higher than the machine-peeled yam. Overall acceptance of sensory characteristics were: the sample processed by electrolyzed water and hydrous treatment (EW-1-S, EW-2-S)>the sample processed by electrolyzed water and anhydrous storage (EW-1-NS, EW-2-NS)>the sample processed by 0.6%AA and hydrous storage (0.6%AA). The results show that electrolyzed water and hydrous storage is effective on the storage of yams.     

Hydrothermal treatments of rice starch for improvement of rice noodle quality

Two types of hydrothermal treated rice starches were prepared by annealing and heat-moisture treatment (HMT). Annealing of starch slurry was conducted at 55 °C for 24 h and HMT was applied in starch with 20 g/100 g moisture at 110 °C for 1.5 h, based on the optimization of the treatment conditions. The apparent changes on gelatinization, swelling, RVA paste viscosities and gel hardness of starch were observed. The study on 50% substitution of rice flour with untreated (UR), annealed (AR) or heat-moisture treated (HR) rice starches proved that the cooking and texture quality of rice noodle was substantially affected by the treatments. The composite noodles of flour and hydrothermal treated rice starches exhibited quality parameters which were closer to those of commercial noodles. The results revealed the possibility of utilizing these starches with low quality rice flour so as to produce noodles of acceptable quality. The study also inferred that characterization of RVA paste viscosities and gel texture of flour could become a practical method for predicting the quality of the derived noodle.     

Suitability of pigeon pea and rice starches and their blends for noodle making

The physicochemical and pasting properties of pigeon pea and rice starches were studied to assess their suitability for noodle making. Amylose content, solubility and freeze thaw stability of pigeon pea starch were significantly higher than those of rice starch (p < 0.05). The pasting properties of peak viscosity, final viscosity, breakdown and set back showed higher values for pigeon pea starch, whereas hot paste viscosity and pasting temperature were higher for rice starch. Rice starch noodles revealed less cooking time (4 min) and less percent solids loss, whereas pigeon pea starch noodles had higher cooking time (12 min), higher percentage of water absorbed during cooking, more hardness and cohesiveness. Rice starch noodles scored higher for their transparency and slipperiness over pigeon pea starch noodles. Blending of pigeon pea starch with rice starch had significant effects on the cooking and sensory quality of noodles. Among starch blends, 70:30 blend of the pigeon pea and rice starches respectively resulted in good quality of noodles especially in terms of their higher transparency, slipperiness, overall acceptability and cohesiveness values. Blending of pigeon pea starch with 30% rice starch could produce noodles with superior quality as compared to native pigeon pea and rice starch noodles.     

Effect of electrolyzed reduced water on chiral theanine and polyphenols in tea

Pure d/l-theanine enantiomers were synthesized separately, and SEM was used for their crystal-structure observation. The novel enantiomeric separating method by HPLC was established using the chiral selector of β-CD in the mobile phase. Green tea, white tea, oolong tea, black tea and Pu-erh tea were tested for theanine enantiomers by different degrees of fermentation. The significantly higher d-enantiomeric proportion of theanine was found in white tea than the others, which was probably due to its specific processing step of withering. The effect of electrolyzed reduced water (ERW) on enantiomeric theanine and polyphenols in tea was explored. There was no change of theanine, but rather a loss of ECG (epicatechin gallate) and an increasing amount of GA (gallic acid). ERW also reduced tea cream, which contains significant amount of polyphenols, indicating its potential application in the tea-beverage industry.     

米线中菌落总数测定结果的不确定度评估

目的对米线中菌落总数测定结果的不确定度进行评估。方法根据GB4789.2-2016《食品安全国家标准食品微生物学检验菌落总数测定》对米线中的菌落总数进行测定,通过建立评估的数学模型,分析不确定度的主要来源,计算出不确定度的各主要分量,得出合成不确定度和扩展不确定度。结果在置信水平为95%时,合成不确定度为0.23856,扩展不确定度为0.49764。结论影响结果不确定度的主要因素为样品的均匀性和重复测定,该评估系统可为今后实验室测定食品中菌落总数的不确定度评估提供参考,为检验检测结果的科学表达提供依据。     

热处理及不同浓度食盐对生鲜面条品质及货架期的影响

本文以复配水分活度调节剂为基本配方,探究热处理及不同浓度的食盐对生鲜面条水分含量、水分活度、水分分布、色泽、蒸煮以及质构、糊化特性的影响。试验结果表明:热处理和添加不同浓度的食盐降低了生鲜面的水分活度,当食盐的添加量为3%时,98 ℃热处理后生鲜面条的水分活度达到最低为0.884。热处理降低了生鲜面条中水分的自由度,增加了生鲜面条中结合水的含量;在不添加食盐的条件下,与未经热处理的样品相比,98 ℃热处理使生鲜面条的亮度从91.07提高至92.93,总色差ΔE从10.04降低为3.06。在88 ℃热处理条件下,随着食盐含量的增加,生鲜面条的硬度、拉断力和拉伸距离先增加后降低,当食盐的添加量为3%时,热处理后生鲜面条的硬度变化与未经热处理的生鲜面条硬度(4471.81 g)没有显著性差异,热处理使生鲜面条糊化特性中的峰值黏度降低,糊化温度升高。此外,热处理和一定浓度的食盐可延长生鲜面条的货架期,在食盐的添加量为2%,98 ℃热处理4 min的条件下制备的生鲜面条于25 ℃储藏其货架期可达96 h。     

江西省米粉镉污染情况分析及米粉食用人群暴露风险评估

目的 了解江西省市售米粉镉污染现状,评估米粉食用人群镉暴露的健康风险。方法 在江西省11个地区采集市售干、鲜生米粉样品163份,采用电感耦合等离子体质谱法（ICP-MS）检测镉含量;采用食物频率调查法在对应地区开展米粉食用人群消费量调查,运用简单分布评估方法,评估江西省米粉食用人群米粉镉暴露健康风险。结果 江西省163份米粉镉总检出率和超标率分别为87.1%（142/163）和1.23%（2/163）,含量范围为0.003~0.225 mg/kg,平均值和中位值分别为0.034和0.020 mg/kg。干米粉镉含量和检出率均高于鲜湿米粉。米粉食用人群米粉镉每月暴露量均值和P₉₅分别为1.11和3.46 μg/（kg·BW）,分别占镉每月可耐受摄入量［PTMI,25 μg/（kg·BW）］的4.4%和13.8%,儿童和青少年米粉镉暴露量高于18岁以上人群;鹰潭市米粉消费人群镉暴露量最高［2.57 μg/（kg·BW）］,其次是宜春［2.39 μg/（kg·BW）］、萍乡［1.94 μg/（kg·BW）］和抚州［1.88 μg/（kg·BW）］。结论 江西省市售米粉中镉污染总体水平较低,米粉食用人群通过米粉摄入镉的暴露风险处于可接受水平。     

HACCP在软包装米粉生产中的应用

应用HACCP原理对软包装米粉的生产进行危害分析，确定显著危害和关键控制点是在关键控制点上设立关键限值．进行重点监控、记录、纠偏和验证，从而保证工业化米粉生产的安全性。     

Study of the physicochemical and pasting properties of instant corn flour added with calcium and fibers from nopal powder

This work presents a physicochemical and apparent viscosity characterization of commercial nixtamalized corn flours (CNCF) added with nopal powder. The chemical proximate analysis of CNCF and traditional nixtamalized corn flours (TNCF) shows equal amounts of protein and fat, but the calcium content and total dietary fiber is higher in the TNCF. Nopal powder contains a high amount of Ca, soluble and insoluble fiber. The inclusion of 4% of nopal powder increases the calcium and fiber content of the CNCF to the level of traditional nixtamalized products steeped at 7 h. A pasting characteristics analysis based on the profile curves was done in order to study the influence of soluble and insoluble fibers on the pasting conditions of the studied samples added with nopal. At low temperatures the insoluble fiber governs the water absorption and below the gelatinization temperature (T_g) a competition between starch swelling and water absorption was found; for T higher than T_g the system is complex because it includes the interactions between soluble–insoluble fibers and exuding amylose.     

青海省不同品种马铃薯全粉品质及结构分析

以青海省六种马铃薯为原料制备马铃薯全粉,通过对其理化、功能性质和微观结构的测定与分析,明确不同品种马铃薯全粉的品质和结构特性。结果表明:六种马铃薯全粉灰分含量范围为3.33%~5.12%,闽薯灰分含量较高,青薯9号和乐薯的脂肪和蛋白质含量均较高,青薯2号的还原糖含量最高,为6.34%±0.29%;青薯9号的持油能力(1.69±0.12) mL/g和黏度(1440±10) cps高于其他品种,脱毒175的吸水指数较高,闽薯的溶解度最高,为14.9%±0.7%;不同品种马铃薯全粉所含官能团并无差异,整体均呈现不规则形状,可见范围内基本无完整颗粒存在,衍射峰形相似,青薯2号全粉颗粒的衍射强度较高,结晶区较大。不同马铃薯在品质和结构方面有一定的差异,可根据实际加工需要选取较适合的品种。     

Influence of Annealing Temperature on Tg′ of Cooked Rice Stick Noodles

T_g′, a glass transition temperature under conditions of maximal freeze concentration, is important to the stability of frozen food. The procedures for using differential scanning calorimetry (DSC) to measure T_g′ have been reported under different experimental conditions. The aims of this study were to investigate the T_g′ of cooked rice stick noodles, and to determine the effect of the annealing temperature on its T_g′ value using DSC. Cooked rice stick noodles in aluminum DSC pans were scanned from ?60°C to 25°C at 5°C/min. to locate the apparent T_g′, which was ?5.3°C in the non-annealed state. When subjected to 4 different annealing temperatures of ?2, ?6, ?8 and ?10°C for 15 minutes, the T_g′ of cooked rice stick noodles was ?5.3, ?4.0, ?4.2, and ?4.9°C, respectively. The value of T_g′ was clearly observed in the annealed sample at ?6°C. The annealing process allowed time for the maximum formation of ice. This study showed that annealing at a temperature slightly below T_g′ gave a higher and more accurate value.     

谷物膨化混合粉的应用研究

以优质的黑米、薏米、荞麦粉为原料,采用现代挤压膨化技术制成膨化粉,将膨化粉按一定比例添加到小麦粉中,分别制作出营养保健价值很高的馒头、蛋糕、烤糕,研制出相应的馒头制作工艺、蛋糕制作工艺、烤糕制作工艺和工艺参数。     

In vitro multienzyme digestibility of protein of six varieties of African yam bean flours

The in vitro multienzyme protein digestibilities of the flours of six varieties of African yam bean (Sphenostylis stenocarpa), made from both whole seeds and dehulled seeds were investigated. The multienzyme system consisted of trypsin, chymotrypsin and peptidase. Digestibilities were determined for a 10 min digestion period. Both dehulling and heat treatment improved digestibility. Comparison of flours from raw whole seeds with those from dehulled seeds showed that digestibility was better in the latter, with an increase of 6.78%. Heat-treated whole seed flcurs gave a digestibility increase of 6.06% compared with raw flours whereas in the dehulled samples the digestibility increase of heat-treated flours over raw was 5.19%. Heat-treated dehulled seeds were better, with a digestibility increase of 5.90% over the heat-treated whole seed flours. No significant differences (P < 0.05) were observed in the digestibilities among the whole seed flours but significant differences were observed in the dehulled seed flours.     

方便面微波干燥效果的研究

微波干燥方便面是一种非油炸方便面,它避免了油炸方便面中高脂肪对人体健康的危害,产品的口感、色泽、韧性、爽滑性、适口性和复水性等方面均优于其他非油炸干燥方法.本文以方便面的水分含量、复水时间、感官评价等指标为依据,研究了影响微波干燥方便面干燥效果的因素.结果;水煮时间、微波干燥时间、微波功率对干燥效果均有影响,正交实验试验表明,水煮时间3min,微波干燥3.5min,微波功率600W时,微波干燥方便面的干燥效果最好.     

国内外面条的研究进展

面条是中国及亚洲其他一些国家和地区最常见的传统面食。本文对国内外面条的研究进展进行了综述：主要包括（1）小麦品种品质与面条品质的相关性研究状况；（2）面条的制面工艺与面条食用品质的相关性研究状况；（3）面条品质改良剂的研究状况以及新一代方便面－－新鲜面的研究现状。