野葛与粉葛淀粉的结构及物化特性比较

本文对比野葛和粉葛两种葛根淀粉成分、物化特性,两种淀粉及其各自直链淀粉和支链淀粉结构特性,结果表明:野葛、粉葛淀粉的脂肪、粗纤维、灰分含量存在显著差异(p<0.05),淀粉、蛋白质、直链淀粉含量无显著差异(p>0.05);野葛、粉葛淀粉平均粒径分别为26.15μm、8.65μm,野葛、粉葛淀粉晶型均为C型,野葛、粉葛直...     

生物工程在食品领域的研究与应用进展

随着人民生活水平的改善,对食品品质的要求不断提升,食品产业必须引入先进技术和理念才能应对新时代的市场需求。生物工程作为食品产业的核心技术之一,对食品原料加工、食品添加剂开发、食品防腐技术革新等产生重大影响。随着“健康中国2030”计划的实施,生物工程将在食品领域中扮演更加重要的角色,作者针对近年来食品生物工程领域的研究进展进行综述,为相关产业升级提供借鉴。     

二氧化氯和臭氧杀菌处理对菜心贮藏品质的影响

为提高菜心贮藏品质,研究二氧化氯(ClO2)、臭氧(O3)两种杀菌剂对菜心贮藏期间的呼吸强度、丙二醛含量、过氧化物酶活等品质指标变化规律的影响。研究发现,与对照组相比,在贮藏期内ClO2和O3对菜心呼吸的影响是先促进后抑制,二者均使菜心呼吸高峰提前到达,但贮藏中后期(6 d^9 d)杀菌组的呼吸强度低于对照组,ClO2对呼吸的抑制优于O3;ClO2和O3提高了菜心贮藏前期的硬度,贮藏后期ClO2组菜心硬度适中;ClO2降低了菜心a*值,有利于保持菜心的绿色;O3对菜心a*值略有提高,对菜心绿色影响不显著;ClO2和O3促使菜心中丙二醛的累积,但量小难以促衰老;ClO2能稳定维持偏低的过氧化物酶活性,抑制苯丙氨酸解氨酶活性,延缓其木质化和衰老,保持品质。综合分析得出,ClO2更适合杀菌处理菜心,货架期可达12 d,具有潜在的应用前景。     

A Review on Mycotoxins in Food and Feed: Malaysia Case Study

Fungi are distributed worldwide and can be found in various foods and feedstuffs from almost every part of the world. Mycotoxins are secondary metabolites produced by some fungal species and may impose food safety risks to human health. Among all mycotoxins, aflatoxins (AFs), ochratoxin A (OTA), trichothecenes, deoxynivalenol (DON and T‐2 toxin), zearalenone (ZEN), and fumonisins (FMN) have received much attention due to high frequency and severe health effects in humans and animals. Malaysia has heavy rainfall throughout the year, high temperatures (28 to 31 °C), and high relative humidity (70% to 80% during wet seasons). Stored crops under such conditions can easily be contaminated by mycotoxin‐producing fungi. The most important mycotoxins in Malaysian foods are AFs, OTA, DON, ZEN, and FMN that can be found in peanuts, cereal grains, cocoa beans, and spices. AFs have been reported to occur in several cereal grains, feeds, nuts, and nut products consumed in Malaysia. Spices, oilseeds, milk, eggs, and herbal medicines have been reported to be contaminated with AFs (lower than the Malaysian acceptable level of 35 ng/g for total AFs). OTA, a possible human carcinogen, was reported in cereal grains, nuts, and spices in Malaysian market. ZEN was detected in Malaysian rice, oat, barley, maize meal, and wheat at different levels. DON contamination, although at low levels, was reported in rice, maize, barley, oat, wheat, and wheat‐based products in Malaysia. FMN was reported in feed and some cereal grains consumed in Malaysia. Since some food commodities are more susceptible than others to fungal growth and mycotoxin contamination, more stringent prevention and control methods are required.     

人工发酵剂对湘西腊肠微生物菌群和理化特性的影响

本文从动态角度探讨自然发酵、戊糖片球菌发酵、木糖葡萄球菌发酵和混合菌发酵腊肠在发酵过程中五种菌相(细菌总数、乳酸菌、葡萄球菌、酵母菌和肠细菌)和理化特性的阶段性变化。微生物数据显示,四组腊肠初始肠细菌数量约5.30 logCFU/g,而发酵结束,添加了戊糖片球菌腊肠组的肠细菌数量约1.00 logCFU/g,没有添加该菌腊肠组的肠细菌数量约3.30 logCFU/g,说明戊糖片球菌能有效抑制肠细菌的生长,保证了产品的安全性和稳定性;发酵初期,腊肠p H值迅速降5.30以下,到发酵中期,腊肠p H开始回升;在发酵过程中,戊糖片球菌腊肠组的TBARS(硫代巴比妥酸)值显著(p0.05)高于其他三组腊肠,而其它理化特性无显著差异。从数据分析可知,腊肠的发酵剂能有效改善其卫生质量,而对腊肠的p H值、AW和亚硝酸盐残留量没有显著影响。     

High Performance of Paper Strength and Energy Savings in OCC Pulp Papermaking via MFC Addition

Fiber screen fractionation of recycled old corrugated container(OCC) pulp and subsequent targeted processing of each fraction can lead to higher fiber quality, more uniform pulp, and increased handsheet strength and surface smoothness. This pilot-scale study evaluates the benefits of fiber fractionation using a pressure screen prior to low consistency(LC) refining. A 0.81-mm smooth holed screen cylinder is utilized, and two refiner plate patterns are adopted(wide 0.99 km/rev BEL and interim 2.01...     

食盐浓度对腌制茭白理化性质及品质的影响

研究5％、10％和15％不同食盐浓度对生腌茭白发酵过程中pH值、总酸、平衡盐度、亚硝酸盐和氨基酸态氮等理化指标及发酵程度、色泽和质构品质的影响.结果表明:腌制食盐浓度10％时,可快速启动发酵,同时抑制发酵过程中其它微生物的生长繁殖,pH值下降至3.42,总酸含量增加至0.38 g/100 g(以乳酸计),平衡盐度和氨基...     

天津市市售畜肉及肝脏中β-受体激动剂残留状况及膳食暴露风险评估

目的 了解天津市市售畜肉及肝脏中β-受体激动剂残留水平及人群膳食暴露风险。方法 2016—2021年在天津市超市、网店和农贸市场采集市售猪、牛、羊肉及肝脏样品583份。按照《国家食品污染和有害因素风险监测工作手册》的相关标准程序进行克伦特罗、莱克多巴胺、沙丁胺醇和特布他林4种β-受体激动剂的检测,结合居民食物消费量采用食品安全指数法评价人群膳食暴露风险。结果 583份样品总检出率为13.89%（81/583）。克伦特罗为主要检出的β-受体激动剂,占总检出样品的98.77%（80/81）,仅1份样品检出沙丁胺醇,而其他两种β-受体激动剂则均未检出。检出率位于前3位的食品种类为牛肝33.96%（36/106）、羊肉15.79%（18/114）、牛肉13.22%（16/121）,猪肉、猪肝检出率较低,分别为1.19%（1/84）、2.00%（1/50）,差异有统计学意义（χ²=56.11,P?0.05）。农贸市场采集样品检出率显著高于超市及网店（χ²=10.91,P?0.05）。暴露评估结果显示,天津市居民通过猪肉、牛肉、羊肉的β-受体激动剂的平均暴露量范围为0.000 1~0.000 4 μg/kg·BW;食品安全指数（IFS）范围为0.022 0~0.095 0,IFS值均小于1。结论 天津市市售畜肉及肝脏中β-受体激动剂存在一定程度的检出,但通过猪肉、牛肉、羊肉β-受体激动剂的平均膳食暴露的食品安全风险处于较低水平。     

Rheological, texture and sensory properties of low-fat mayonnaise with different fat mimetics

Application of whey protein isolate and low-methoxy pectin-based fat mimetics in mayonnaise was studied. Fat was partially substituted by different fat mimetics at levels of 50%, respectively, which the fat mimetics were referred to as PFM1 (microparticulate pectin gel), PFM2 (pectin weak-gel), and PFM3 (microparticulated combination of WPI and pectin). The full fat (Ff) (100% oil) mayonnaise without fat mimetic was used as a control experiment. Physicochemical, rheological, texture analysis, and sensory evaluation of the Ff and low fat (Lf) mayonnaises were performed. The results indicated that all Lf mayonnaises had significantly lower energy content, but higher water content than their Ff counterpart. In terms of texture, the formulation with pectin weak-gel as fat mimetic showed similar texture values as those of the Ff sample. Both Ff and Lf mayonnaises exhibited thixothopic shear thinning behaviour under steady shear tests and were rheologically classified as weak gels under small amplitude oscillatory shear tests. Sensory evaluation demonstrated that mayonnaises substituted with low-methoxy pectin were acceptable. This study shows good potential for pectin weak-gel and microparticulated pectin gel to be used as a fat mimetic in mayonnaise.     

Effects of various food products on blood sugar level in patients with diabetes mellitus and obesity

The blood sugar level was evaluated in patients with insulin-independent diabetes mellitus and obesity, and in normal volunteers, during 3 h with a 30-min interval before and after food loading containing 50 g of carbohydrates. It has been found that 17 food products studied produce varying effects on the blood glucose level regardless of the content of starch and sugars in them. Pure glucose, boiled rice, potatoe, white bread, boiled bean, pastry, honey and sugar produce the highest glycemic effect. Milk, ice cream, boiled lens and noodles produce a moderate effect on the blood sugar level both in normal subjects and in patients with diabetes mellitus and obesity. The increase of the glucose blood level after intake of food products was significantly higher in patients with diabetes mellitus as compared to those with obesity and normal volunteers. Milk products, lens, macaroni and millet are most promising for patients with diabetes mellitus due to their moderate influence on the blood glucose content.