Optimisation of a quality improver for instant rice and its quality properties

Three additives were optimised for the sensory characteristics, textural and physicochemical properties of instant rice by using response surface methodology (RSM) and principal component analysis (PCA). Comprehensive evaluation indicated that 0.025% glycerol monolaurate (GML), 0.58% β‐cyclodextrin (β‐CD) and 0.41% alcohol formed a new quality improver of instant rice. Moreover, several specific quality properties of instant rice were further studied. Compared with freshly cooked rice, instant rice with or without optimised additives owned much lower quality. The microstructure observation and pasting properties by Rapid Visco Analyzer (RVA) analysis implied that quality improver could distinctly ameliorate the texture and viscoelastic properties. Simultaneously, the quality improver had no significant effects on the starch digestion. But, it could retard short‐term starch retrogradation of instant rice, namely △H_r value decreasing from 1.511 J g^?1 to 1.386 J g^?1.     

Effect of exopolysaccharide-producing strains of Streptococcus thermophilus on technological attributes of fat-free lassi

Sixty-four exopolysaccharide-producing thermophilic lactic acid bacteria (LAB) were isolated from traditionally made Indian fermented milk products. On the basis of morphological and biochemical tests, these isolates were identified as the species of Lactobacillus, Streptococcus, and Enterococcus genera. Initial screening for technological attributes revealed that Streptococcus thermophilus IG16 was a promising isolate, and produced both capsular and ropy polysaccharides at the concentration of 211 mg/L. Exopolysaccharide produced by IG16 was a heteropolysaccharide containing rhamnose and galactose in a ratio of 5.3:1 and had a molecular weight of 3.3 × 10⁴ Da. Use of IG16 as a starter culture controlled whey separation and improved viscosity, flavor, consistency, and color and appearance of lassi. Use of IG16 resulted in lassi having optimal acidity, less syneresis, high viscosity, and better scores for flavor, consistency, and color and appearance.     

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.     

HACCP在方便面生产中的应用

本文探讨了HACCP在方便面生产中的应用,通过对生产各工序的危害分析,建立了卫生标准操作规范(SSOP)、关键控制点、关键限值、控制方法和验证程序,顾客投诉率下降40％。     

The quality of plain and supplemented kefir from goat's and cow's milk

Goat's or cow's milk was fortified with 2 g/100 g skimmed milk powder (SMP), whey protein concentrate (WPC) or inulin. All the milks were fermented with kefir grains at 25°C for 19 h and stored for 10 days at 5°C. All the kefir samples were analysed on the 1st, 5th and 10th day of storage. The acidity level remained very stable in all the samples during the storage period. Goat's samples have significantly lower viscosity and slightly lower sensory profiles, mostly due to softer consistency. Concentration of ethanol was low, regardless of milk type used, especially for control samples.     

即食黄花菜加工工艺研究

选用不含硫的干黄花菜为原料生产即食黄花菜。调味时，添加复合核苷酸和复合香辛料，可明显优化产品的口感。在配料中添加0．05％的CaCl2，有利于提高产品的脆度，但当CaCl2的浓度达到0．1％时，质地变硬，不化渣。产品用四旋玻璃瓶包装的保存效果最好，保藏期可达到15个月；其次，是用复合铝箔包装，保藏期12个月；再次是以0．08mm聚丙烯(PP)复合蒸煮袋作内包装，0．05mm聚乙烯膜(PE)作外包装的，保藏期为10个月；用0．08mm聚丙烯(PP)复合蒸煮袋单层包装的，保藏期为9个月。在产品中添加0．05％的山梨酸和20多种常用香辛料，包装后再用90℃的热水杀菌5min，以上4种包装的产品都可以保存9个月以上。     

The effects of acetylated potato starch and sodium carboxymethyl cellulose on the quality of instant fried noodles

The objective of this study has been to investigate the effects of two ingredients i) acetylated potato starch (APS) and ii) sodium carboxymethyl cellulose (CMC) on the textural attributes and eating quality of instant noodles. Using low-protein soft wheat flour (Australian Soft) as the base material, samples of noodles incorporating varying proportions of APS and CMC were evaluated for product texture, colour and fat uptake. The variables were studied using a central composite design and textural characteristics were assessed using the TA-XT2, colour by the Minolta Chroma Meter. The results were analyzed by response surface methodology and showed that the two variables enhance the hardness and reduce adhesive values of cooked instant noodles. Electron microscopy also demonstrated the development of a more continuous network structure within the noodles. The addition of CMC had weakened the noodle inner structure and reduced the cohesiveness values of the cooked instant noodles. In contrast, APS provides hardness but does not affect cohesiveness. Marginal observable difference was found in product colour for the various treatment combinations, with a slightly dull appearance, viz less white and less yellow compared with the control. Trials to produce the lowest fat uptake rating indicated that 10% APS was optimal. The results may provide a basis for modifying formulations for use with low-protein soft wheat flours to provide eating quality and colour attributes to meet the preferences of specific customer groups. The conclusion of this study is that the combined use of APS and CMC primarily affects the textural attributes of hardness and adhesiveness rather than the other quality parameters of instant noodle that have been assessed. In addition, APS has the potential to enhance the performance of low-protein soft wheat flours for instant noodle manufacture.     

Minimal clean-up and rapid determination of polycyclic aromatic hydrocarbons in instant coffee

The essential aim of this work is the development of a simple, fast, quantitative and economic method for polycyclic aromatic hydrocarbons (PAHs) potentially generated by roasting coffee beans, which is the most important process in the coffee industry for the development of the characteristic flavour of the bean mix. The PAHs were chosen because they differed in the number of aromatic rings, had different polarity, have low residual limits, are commonly widespread in the environment and are generated by roasting. The key issue is whether or not the most polar PAHs, those with lower molecular weight or less rings, appear in the water extracts of ground roasted coffee beans, taking into account that those PAHs with lower molecular weight are those with higher volatality. The proposed analytical method is also broadly applicable to other roasted foods or their aqueous extracts. The method was evaluated by constructing calibration curves, measurement of recovery and precision, and the limits of detection. The method involves extraction with hexane, clean-up with a silica cartridge, concentration to dryness and injection of the acetonitrile solution of the residue for HPLC analysis with fluorescence detection. The method allowed to confirm or not the presence of the selected PAHs in instant coffees.     

即食风味洋姜片的生产工艺与质量控制

在保持民间腌制洋姜色香味的基础上,工业化生产风味各异的腌制洋姜片并进行真空小包装。在生产过程中,通过控制好工艺条件,可有效地预防腌制洋姜产品失脆、析糖、发黑等常见质量事故的发生。     

Evaluation of sensory quality of instant foods fortified with omega-3 PUFA by addition of fish oil powder

The aim of this study was to evaluate the influence of fish oil powder fortification on sensory quality of selected instant foods. Two kinds of fish oil powders were tested. Upper levels of addition of fish oil powders to various instant foods, which not significantly influenced sensory quality, were established. In the storage test milk-rice kid cereal food with and without flavourings were fortified with fish oil powder and sensory evaluated. Decrease of sensory quality of samples stored in the air-permeable conditions was detected after 1 week (not flavoured) and 3 weeks (flavoured). However, vacuum-packed samples showed no changes in sensory quality. Presence of flavourings allowed higher levels of fish oil addition to instant foods due to masking of undesirable off-flavours. The authors concluded that it is possible to fortify instant foods with microencapsulated fish oil at limited levels, especially when spray-dried powders are used. One portion of fortified instant foods might provide up to 16% of the minimal recommended daily intake of long chain omega-3 PUFA.     

即食液熏鲍鱼生产工艺开发与优化

目的 开发与优化即食液熏鲍鱼生产工艺。方法 以感官评分为指标,通过正交实验,研究液熏液配方和浸渍烘干工艺参数对即食液熏鲍鱼品质的影响。结果 即食液熏鲍鱼最佳生产工艺为[液熏液配方为食用盐添加量(2 %)、白砂糖添加量(10 %)、酱油添加量(3.5 %)、烟熏香味料添加量(0.2 %)和浸渍烘干工艺参数为浸渍时间(2 h)、浸渍温度(60 ℃)、烘干时间(2 h)、烘干温度(80 ℃)];在此最佳生产工艺下加工而成的即食液熏鲍鱼的理化、微生物及污染物指标符合相关食品安全国家标准。结论 开发并优化了一种即食液熏鲍鱼生产工艺,为鲍鱼休闲食品的深加工提供了参考依据。     

嘉兴市即食食品中致病微生物的污染现状调查

目的了解市售食品中食源性致病微生物的污染现状,发现高危食品,为预防和控制食源性疾病提供科学依据。方法在农贸市场、超市和餐饮环节采集与嘉兴市消费者生活密切相关的8类即食食品,开展常见致病微生物监测。结果采集的640份食品样品中,检出致病菌56株,检出率为8.75%(56/640),检出菌株以副溶血性弧菌为主,占总检出数的69.64%(39/56);金黄色葡萄球菌居次位,占14.29%;单核细胞增生李斯特菌、蜡样芽胞杆菌和创伤弧菌占比依次为8.93%、5.36%和1.79%。三季度致病微生物检出率(16.92%)最高,农贸市场、散装食品、水产品检出率相对较高,分别为17.60%、13.30%和25.00%。结论嘉兴市即食食品存在食源性致病微生物污染风险,需加强监督管理、规范食品操作和提高人群健康教育水平。     

我国方便面消费人群膳食钠摄入水平分析

目的 分析我国方便面消费人群膳食钠摄入水平,评估不同情景下降低方便面中的钠含量对方便面消费人群钠摄入水平的影响。方法 应用方便面以及其他食品中钠含量专项监测数据,结合2017—2020年中国居民食物消费状况调查中各类食品个体消费量数据,采用简单分布模型方法,评估方便面消费人群每日膳食钠的摄入水平和分布情况,以及不同食品对膳食钠摄入的贡献。情景假设四种：方便面中的钠含量降低10%、降低20%,食用1/2方便面调料包、食用1/3方便面调料包。结果 本研究采集的方便面样品中钠含量平均值为2 129.30 mg/100 g,方便面消费人群膳食钠平均摄入量为5 462.68 mg/d,所有年龄组人群膳食钠平均摄入量均超过WHO推荐值（2 000 mg/d）,约98.53%的方便面消费人群膳食钠平均摄入量超过相应年龄段预防非传染性慢性病的建议摄入量;调味品是方便面消费人群膳食钠摄入的主要来源,方便面的贡献率约为12.69%。食用1/3调料包时,可使方便面消费人群总钠摄入降低6.74%。结论 我国方便面消费人群钠摄入量处于较高水平,通过降低方便面中钠含量或减少调料包食用量,可在一定程度上降低人群钠摄入水平。本研究为国内方便面行业开展减盐（减钠）行动提供科学数据参考。     

Norharman and harman in instant coffee and coffee substitutes

Norharman and harman are two neuroactive β-carbolines present in several plants and thermally processed foods, including roasted coffee. The objective of this study was to evaluate their amounts in commercial instant coffee-based and coffee substitute beverages (n = 48), with variable amounts of coffee, chicory, barley, malt, and rye. All samples contained variable amounts of both β-carbolines, always with a higher proportion of norharman than harman. The highest levels (p < 0.01) were found in 100% instant coffees, with mean amounts of 3.8 μg/g and 1.5 μg/g for NH and H, respectively, followed by plain chicory. The lowest amounts were found in 100% barley, with 1.1 μg/g for NH and 0.3 μg/g for H. The NH and H content was statistically higher (p < 0.01) in all mixtures with coffee when compared to those without it. Nevertheless, and except for 100% barley, the amounts provided by beverages based on coffee substitutes are within those reported for standard coffee brews.     

Effect of pretreatments and vacuum drying on instant dried pork process optimization

Dehydrated meat which can be instantly rehydrated is needed by the industry. This research was aimed to investigate a more economical drying process. Central composite design was applied with three variables: cooking pressure, cooking time, and vacuum drying temperature. The responses were shear force (N), work of shear (N.mm) and % rehydration. The multiple linear regression equation models could predict 91.7, 90.9 and 94.8% of each response, respectively. Cooked pork meat was used for target responses. Its maximum shear force was 43.39±5.42 N, and work of shear was 419.50±64.17 N.mm. Vacuum drying temperature highly affected all responses. Validation of the predicted data was done using two optimum conditions. First condition was cooking pressure of 21.6 lb/in.(2), cooking time of 50 min, and vacuum drying temperature of 95°C. The second condition was cooking pressure of 38.4 lb/in.(2), cooking time of 35 min, and vacuum drying temperature of 100°C. A t-test confirmed that the observed data were not statistically different from the predicted data.     

即食小米粥的开发工艺及品质研究

实验分析了浸泡温度、β-环状糊精添加量、热风干燥与真空冷冻干燥时间比对即食小米粥的复水率、感官评价、米粒质构的影响,确定最优条件为浸泡温度20℃、β-环状糊精添加量3%、烘干时间/冻干时间=40 min/16 h。在实验工艺和测定参数条件下,小米粥的米粒硬度、黏着性、弹性、咀嚼度、回复性分别在14.27～15.66 N、-0.26～-0.15 NS、0.46～0.53、2.79～-5.35N和0.16～0.19之间口感相对较好。复水率直接影响粥的口感,当复水率在6.3～7.6之间时,小米粥的感官品质相对较好。同时建立感官与复水率、物性测定的间的相关性。     

即食海参体壁失稳的影响因素及其 稳定化方法研究进展

即食海参是一种比干海参营养流失少且食用方便的海参加工产品,但是该类产品在常温贮藏、甚至低温冷藏条件下往往会出现变软、变粘、甚至融化等失稳现象。本文综述了其导致因素,如内源自溶酶、附着微生物、温度、含水量、紫外线照射等,并归纳了低温贮藏技术、真空包装技术、超高压技术、分段式高温杀菌、生物交联技术等解决方法。     

速溶茶中试冻干过程模拟研究

目的 采用数值模拟方法预测和优化冻干速溶绿茶粉的中试试验生产工艺。方法 通过有限元法建立二维传热传质相变模型, 模型模拟茶粉冻干过程中温度场、压力场、水分迁移的变化过程。结果 利用模型优化的生产工艺为: 物料铺盘厚度调整为15 mm, 采用阶段升温方法, 在升华干燥0~2 h、2~4 h、4~6 h、6~8 h及8~26.5 h五个时间段中, 调整环境辐射温度为0、10、30、50、60℃。按上述工艺生产所得的速溶绿茶粉的水分含量(质量分数)是(3.9±0.19)%, 各项理化指标符合国家产品标准要求。结论 该模型的预测结果与试验结果相吻合, 采用数值模拟方法可以用于预测和优化冻干速溶茶粉的中试试验生产工艺, 为今后进一步的产业化生产提供参考与借鉴。     

Parameters affecting the quality of processed cocoa powder: acidity fraction

 Total, free and fixed, volatile and non-volatile acids, as well as lactic and phosphoric acid contents were determined in six samples of three batches of cocoa beans subjected to various stages of fermentation (1–6 days), in 37 samples of non-alkalinized low-fat cocoa powder and in 15 samples of instant cocoa powder. The physico-chemical data obtained were related to sensory evaluation and submitted to analysis of variance, multivariate distribution (Mahalanobis distance) and the Pearson Chi-squared test. From the results obtained we can infer that optimally fermented cocoa samples should have a maximum total fixed acidity of 39 mEq NaOH/100 g, a non-volatile fixed acidity of 35 mEq NaOH/100 g, and a lactic acid content of 0.50 g/100 g (5.5 mEq/100 g). No correlation was found to occur between other acidities, the phosphoric acid content, and sensory data. These parameters are related to the sensory properties of cocoa and can be used to confirm deficiencies. Received: 12 February 1996 / Revised version: 17 June 1996     

真空冷冻干燥制备即食小米粥工艺优化

探索最佳即食小米粥开发工艺及真空冷冻干燥工艺.筛选出适合开发即食小米粥的小米品种,采用模糊数学感官评价法和响应面法优化即食小米粥工艺,正交法优化真空冷冻干燥工艺.结果表明:东方亮小米适合开发即食食品;即食小米粥开发最佳工艺条件为浸泡时间40 min,料液比1:20,熬煮时间30 min,此时得到复水率为14.74,模糊...