Effect of nutmeg (Myristica fragrans) essential oil on the oxidative and microbial stability of cooked sausage during refrigerated storage

This paper examines the oxidative and microbial stability of cooked sausages, produced with the addition of 10 ppm (NO1) and 20 ppm (NO2) nutmeg (Myristica fragrans) essential oil. Instrumental parameters of color (CIE L*, CIE a* and CIE b*), Thiobarbituric acid-reactive substance (TBARS) values, microbial profile and sensory properties of aroma have been determined on the 1st, 30th, 45th, and 60th day of storage. Addition of the nutmeg essential oil had no effect on the color of cooked sausages. At the end of the storage, NO2 sausages had the best oxidative and microbial stability. TBARS values of NO1 and NO2 sausages were 1.21 mg MDA/kg and 0.95 mg MDA/kg, respectively, and were significantly lower (P < 0.05) compared to control (1.53 mg MDA/kg). Total number of aerobic mesophilic bacteria was lowest in NO2 sausages (78.3 cfu/g) and highest in control (185 cfu/g). After 45 and 60 days of storage, sensory properties of aroma of NO1 (4.21; 3.92) and NO2 sausages (4.39, 4.28) were better compared to those in control (4.07, 3.25). Hence, the addition of nutmeg essential oil in amount of 20 ppm can be successfully applied in order to extend the shelf life of cooked sausages.     

Dietary oxidised lipids,health consequences and novel food technologies that thwart food lipid oxidation: an update

Processed foods are popular and their consumption is expected to grow globally. Food processing and manufacturing promote lipid oxidation in foods rich in polyunsaturated fatty acids and cholesterol. This review focuses on how various food manufacturing/processing techniques promote lipid oxidation in grains, meats and meat products, dairy and fats/oils. This review also considers emerging evidence from animal and human studies that suggest a link between dietary oxidised lipid consumption and chronic disease risk. An update on novel food technologies that limit food lipid oxidation is discussed so as to inform both food scientists and dietitians/nutritionists to direct future efforts in not only continuing to bring these novel technologies to the market place but also conduct clinical trials to establish their role in human health.     

Nutritional and sensory quality of porcine raw meat, cooked ham and dry-cured shoulder as affected by dietary enrichment with docosahexaenoic acid (DHA) and α-tocopheryl acetate

The effects of dietary enrichment of pig diets with DHA from a marine source (Algatrium^®) and α-tocopheryl acetate on the nutritional and sensory characteristics of pork and pork products were evaluated. Raw and cooked hams, and dry-cured shoulders from pigs fed with three diets (control, control supplemented with 0.3% DHA plus 50 ppm α-tocopheryl acetate and control with 200 ppm α-tocopheryl acetate) were used. The treatments did not cause any significant differences in proteolytic and antioxidant enzyme activities, except on catalase (CAT) which increased significantly in raw hams from pigs fed DHA supplemented diets. Vitamin E accumulated in samples with α-tocopheryl acetate supplementation. DHA added to the diet increased the DHA level by 87% compared with the control treatment in both raw and dry-cured shoulders, and exceeded 82% in cooked hams. In consequence, the incorporation of the n − 3 source in the diet significantly reduced the n − 6/n − 3 ratio in all products. The ratio reduction ranged from 51% in dry-cured shoulders to 65% in cooked and raw hams.     

离子色谱法测定肉类中总硫的含量

目的建立肉类中总硫含量的离子色谱(ion chromatography, IC)检测方法。方法肉类经过粉碎、混合均匀后,于70℃真空烘干3 h。取50 mg烘干的样品与100 mg褐煤混合燃烧,产生的二氧化硫、三氧化硫用艾士卡试剂(Eschka)吸收转化成硫酸盐。用10.0 mL去离子水溶解艾氏卡试剂,取稀释后的上清液过水相膜进样。经阴离子交换柱分离,用离子色谱法对硫酸根离子进行检测,采取外标法定量。结果硫酸根离子在0.0781～10.0 mg/L范围内线性关系良好,相关系数大于0.999。方法检出限、定量限分别为4.00和10.0 mg/kg;相对标准偏差为9.15%～14.7%。结论该方法简便、基质干扰小;其准确度、检出限等参数均能满足相关的技术规范的要求,适合用于市售肉类中总硫的检测。     

高效液相色谱法测定熟肉制品中8种合成着色剂

目的建立高效液相色谱法同时快速测定熟肉制品中8种合成着色剂的检测方法。方法称取粉碎后的样品于离心管中,加入碱性乙醇溶液提取合成着色剂,用硫酸溶液和钨酸钠溶液去除蛋白,滤液经浓缩后定容。样液过滤后经Agilent C18(5μm, 250 mm×4.6 mm)色谱柱分离,,流动相为0.02 mol/L NH4Ac(pH 6.86)和甲醇,流速为1.0mL/min,柱温40℃。采用二极管阵列检测器在254nm波长处进行检测,外标法定量。结果该方法在0.5～10.0 mg/kg线性范围内(靛蓝为1.0～20.0 mg/kg)线性良好,相关系数均大于0.990,检出限为0.1～1.0μg/kg,平均回收率为80.8%～104.7%,相对标准偏差为4.29%～4.87%。结论该方法操作简单、灵敏度高、重复性好,满足同时检测熟肉制品中8种合成着色剂的要求。     

Structure of Cooked Spaghetti of Durum and Bread Wheats

The structure of cooked spaghetti of durum and bread wheats was studied using low voltage scanning electron microscopy, and light microscopy applying different staining methods. Central, intermediate and external regions, and four zones along the external region of cooked spaghetti strands, were characterized in unprecedented detail. Changes in structure of starch granules from core to surface portrayed the successive stages in starch gelatinization, and possible starch retrogradation in the external region. Pronounced changes in shape of starch granules commenced in the intermediate region, while apparent internal changes dominated in the external region. Spaghetti of bread wheats differed from that of durum wheats by the larger size and higher extent of fusions and retrogradation of starch, and less amounts and continuity of intervening proteins. The significance of a high protein concentration for pasta production from bread wheats was emphasized. Furthermore, the relevance of a small size of the large starch granules was inferred.     

带汤汁熟食品真空预冷飞溅现象分析及防止研究

真空预冷带汤汁熟食品时,会发生汤汁飞溅现象。为防止飞溅,选取番茄蛋汤作为研究对象,分别采用分段式降压法和回压法进行实验并与自动式降压法进行了对比,发现两种方法均可有效防止沸腾飞溅的发生,使失水率减少38%,但冷却时间也会相对延长。     

Effect of different pressure-soaking treatments on color,texture, morphology and retrogradation properties of cooked rice

The hydration of rice grain and the quality of cooked rice with the different pressure soaking treatments were estimated using Chroma meter (CM), Texture Profile Analysis (TPA), Scanning electron microscopy (SEM), and Differential Scanning Calorimetry (DSC). The results showed that the vacuum soaking and the high hydrostatic pressure (HHP) soaking increased the hydration degree of normal rice, while the hydration effect in waxy rice was increased only by the HHP treatment. The lightness (L*) and the color intensity (B) of cooked normal rice and waxy rice were significantly improved by the two treatments. The HHP soaking also generated the lower hardness, while the higher springiness and cohesiveness for cooked normal and waxy rice samples. These highlights were mainly attributed to the less amylose leaching and the smaller network channels formed between starch granules and other connection parts. Furthermore, the retrogradation of cooked normal and waxy rice was reduced by the HHP treatment. These findings suggest that the HHP soaking could be used for producing high-quality of cooked rice.     

色泽异常肉的检验和处理

本文通过对市场上五种常见色泽异常肉的检验与处理,为广大消费者提供了便利的鉴别手段,使“吃上放心肉”提供了可靠的依据,并在此基础上技术上有了新的改进。通过临床实践经验,采用对比法以及实验室快速检验法对五种常见色泽异常肉进行不同程度的处理。通过检验和处理常见色泽异常肉,反映了我国市场存在的严重问题,有待于我们进一步加强动检法。