牛肉汁致突变性的研究

在用鼠伤寒沙门氏菌(Salmonella typhimurinm)雨株TA 98研究了熬煮牛肉汁的致突变性。结果表明,牛肉汁的致突变性水平取决于熬煮的时间和浓度,而与其色度无关。     

不同烹调方法对骨汤中钙含量的影响

为寻找适合大众需要的膳食钙源,用原子吸收光谱仪分析了不同烹调方法烹制的骨汤中钙含量,并探讨烹调时间对骨汤中钙含量的影响。结果显示,常用的烹调方法（包括家用压力锅和瓦堡）熬出的猪骨汤中钙含量极低,平均10～1．2mg／100ml,作为人体的钙营养补充意义不大。但加入食醋后,骨汤中钙含量明显增加（P＜0．01）,钙浓度达1780±11．6mg／100ml,且随着烹调时间的延长。汤中钙含量也显著增加（P＜0．01）,可作为一种丰富的膳食钙源。     

不同类型烟草焦油致突变性的研究

通过对五种不同类型烟草焦油致突变性的研究表明，（１）对于烟草焦油来说，其致突变成分在引起鼠伤寒沙门氏菌回复突变方面是以移码型为主，且需要微粒体酶的激活，属于间接致突变物质。（２）不同类型间，焦油致突变性差异极显著，依次为烤烟〉晒黄烟≥晒红烟≥香料烟〉白肋烟。     

反复使用煎炸油对油条的致突变性影响

用鼠伤寒沙门氏菌(Salmomella typhimurium)TA系列菌株TA97检测了反复使用煎炸油对油条的致突变性影响．油条的石油醚提取物的极性部分在加S-9混合液时,菌株TA97的回复突变数增加．油条的石油醚提取物的非极性部分在加或不加S-9混合液时。菌株TA97的回复突变数都没有增加．油条的甲醇提取物在加S-9混合液时,菌株TA97的回复突变数显著增加。     

丙烯醛致突变性研究进展

丙烯醛与DNA可形成加合物,并可形成DNA-DNA、DNA-蛋白质2种交联结构,从而表现出不同的致突变性。丙烯醛致突变性研究结论不一,归因于不同研究对象、靶细胞、试验方法。最近对吸烟者肺组织细胞中丙烯醛-DNA加合物的分析,以及对P53热点突变谱的研究,为丙烯醛致突变性提出了新的证据。      

用rpsL基因突变实验评价丙烯酰胺致突变性的方法初探

采用rpsL基因突变实验对丙烯酰胺的致突变性进行了初步研究。实验设0.05、0.10、0.25、0.50、1.00 mg/mL 5个丙烯酰胺的剂量组和阴性、阳性对照组。结果发现,丙烯酰胺剂量组的突变频率与阴性对照组相比均有显著差异,并且有剂量效应关系,表明丙烯酰胺可诱发rpsL位点的突变。由于rpsL突变实验自发突变背景水平低、灵敏度高,因此rpsL突变实验有望成为食品和医药领域中致癌物快速检测的有效工具。     

The Effect of Cooking Water Composition on Textural and Cooking Properties of Spaghetti

The effect of cooking water on both textural and cooking properties of spaghetti was investigated for spaghetti samples, which differ in protein content. The samples were analysed after cooking in deionised, laboratory tap water, deionised water with 2.5% salt and deionised water with 5.0% salt. Brands A, B, and C were usual durum wheat spaghetti and brand D was spaghetti enriched with bran. Regardless of the cooking water used, brand D had higher hardness and lower adhesiveness than other spaghetti samples and required longer cooking time to achieve optimum cooking. It was found that samples cooked deionised water had lower hardness and adhesiveness values as compared to samples cooked in salty water. It can be concluded that a certain amount of salt in the cooking water improves textural characteristics of cooked pasta.     

热塑挤压技术对食品营养成分影响的研究进展

热塑挤压技术由于其高效多功能以及低成本和低能耗等优势,在食品领域中的应用越来越广泛。挤压蒸煮对营养品质的影响具有双重性,有利影响包括破坏抗营养因子、提高蛋白质消化率、促进淀粉凝胶化、增加水溶性膳食纤维和减少脂肪氧化等,不利影响包括加剧了蛋白质与还原糖之间的美拉德反应、对热不稳定的维生素可能会有不同程度的损失,这主要取决于原料的类型,成分和工艺条件。本文综述了近年来热塑挤压技术对食品中营养成分影响的研究情况,以期为食品挤压加工业提供技术参考。     

Cooking method and endpoint temperature effects on sensory and color characteristics of pumped pork loin chops

The objective of this study was to evaluate the effects of pumping, cooking method and endpoint temperature on quality of fresh pork chops. The longissimus was removed from 30 paired pork sides. One side was pumped to 110% of original weight (0.4% phosphate, 0.4% salt+added water). Chops were cut (2.5 cm thick) then fried or grilled to 70 or 80 °C. As endpoint temperature increased from 70 to 80 °C, pork flavor increased (P<0.05) from 95 to 104 (on a 150 point scale) for pumped samples but remained constant in unpumped samples. Juiciness decreased when unpumped samples cooked to 80 °C (62) rather than 70 °C (78). Warner–Bratzler shear values were lower (P<0.05) in pumped chops than in unpumped controls. Pork flavor was higher and off-flavor was lower in fried chops. Pumping loins appears to enhance sensory attributes of chops even when cooked to abusive endpoint temperatures with limited detrimental effects on physical characteristics.     

不同烹调方法对蔬菜中β—胡萝卜素含量的影响

用高效液相色谱法（HPLC）对不同烹调处理的蔬菜中的β-胡萝卜素含量变化进行了研究。结果表明：漂烫、气蒸、油炒对蔬菜中β-胡萝卜素的影响较小，其保存率依次为93．5±3．06％、88.7±1.45％、81.6±1.73％，变异系数依次为3.3％、1．6％、2．1％，而炖煮对蔬菜中β—胡萝卜素影响较大，其保存率为71．6±5．73％，变异系数为8．0％。     

Sterol Content of Fish,Crustacea and Mollusc: Effects of Cooking Methods

Sterol contents (desmosterol, cholesterol, stigmasterol, and sitosterol) of 36 fresh and cooked seafood and four freshwater fish species were investigated by high performance liquid chromatography (HPLC) method. Cholesterol and sitosterol were main sterols in seafood and freshwater fish species. Raw shellfish and molluscs contained cholesterol above 18.92 mg/100 g fish muscle, while the cholesterol content of marine fish ranged from 6.5 to 78.40 mg/100 g fish muscle. The cooking process resulted in significant effects on the sterol contents of seafood and freshwater species (p < 0.05). A remarkable increase in sitosterol (more than 3–4 fold compared to raw fish) was recorded for some fish species cooked in the oven. The highest desmosterol content was observed for fried fish, whereas the frying process resulted in a significant loss in cholesterol and sitosterol contents of marine fish (p < 0.05). The impacts of cooking methods on sterol content of seafood and their form varied depending on fish species and the cooking method used.     

龙虾片挤压食品研究

本文对龙虾片的蒸煮挤压工艺进行了探索性的研究,发现在挤压机筒温度T_b=90℃,挤压螺杆旋转速度V_s=78r/min,绝对干料进料速度V_F=150g/min~(-1)以及物料水分含量M_c=50%的工艺条下,可以生产出品质优良的龙虾片。本文还就龙虾片的油炸膨化机理进行了讨论。     

不同烹制模式对鸡汤中鸡肉营养及风味特征的影响

研究电磁加热、电热盘加热和瓦罐烹制模式对鸡肉营养成分、质构和风味特性、蛋白质和脂肪消化性的影响。结果表明：烹制模式对鸡肉的感官品质和营养特性具有较大影响。电磁加热模式烹制鸡肉的综合感官品质优良,具有质地柔嫩、香气浓郁、滋味鲜美、风味成分较丰富等特点,同时鸡肉的维生素、脂肪、必需氨基酸含量较高,蛋白质的消化率较好;瓦罐模式烹制鸡肉中蛋白质和矿物质含量较高,脂肪消化率高;电热模式烹制鸡肉的各项指标介于上述2 种烹制模式之间,其中,电磁加热模式烹制鸡肉中的VB3含量达10.34 mg/100 g,粗脂肪含量为5.58%,蛋白质消化率为33.31%;另外,鸡肉中的醛、酮、酯类物质含量亦较高,挥发性物质种类可达37 种。总体来讲,电磁加热是一种较好的鸡肉烹制模式。     

DDS间歇置换蒸煮的特色

介绍了3种蒸煮系统(DDS间歇置换蒸煮、低固形物连续蒸煮和二代紧凑式连续蒸煮)的特点.重点介绍了DDS蒸煮具有原料适应性强、蒸煮工艺灵活、维护简便的特色.     

Cooking DNA: the effect of ‘domestic’ cooking methods on detection of GM potato

The ability to detect GM material in otherwise unprocessed foods cooked using domestic methods is important should ‘ready‐to‐eat’ foods require labelling. This study addresses the issue of DNA degradation in foods as a result of cooking. A number of ‘domestic’ cooking methods were shown to affect the length of DNA sequences able to be PCR amplified from potato samples and the degree of degradation was treatment‐specific. However, a. real‐time PCR assay was developed and. GM material was positively identified in all cooked GM potato samples. This confirms that GM material should be able to be detected in otherwise unprocessed food samples cooked using domestic methods, even if the cooking process has partially degraded the DNA. Results indicate, however, that there may be implications of the cooking process on the ability to accurately quantify GM content in some cooked samples.     

Effect of Domestic Cooking Methods on Antioxidant Capacity of Fresh and Frozen Kale

The aim of this study was to evaluate the changes in the antioxidant capacity of fresh and frozen kale during domestic cooking methods (e.g., boiling, microwaving, and steaming). The antioxidant activities of the samples were measured using three in vitro assays (1,1-diphenyl-2-picrylhydrazyl assay, 2, 2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid assay, and ferric reducing antioxidant power assay). The steaming treatment was found to be the best cooking method to retain antioxidant compounds, followed by the microwaving and boiling treatments. The frozen uncooked samples exhibited a higher antioxidant capacity than the fresh, uncooked samples, indicating that the freezing process could enhance the antioxidant capacity of the kale.