酒醅温度调控对清香型白酒发酵过程的影响

以传统发酵为对照,在实验室条件下模拟清香型白酒的发酵,并对发酵过程酒醅温度进行了控制。通过比较发酵过程酒醅理化性质的变化方式以及发酵所得原酒风味成分,发现酒醅温度及其变化模式对酒醅微生物群落的生长和代谢产生显著影响。通过检测发现实际生产中地缸内温度不均匀,存在温度场。测定地缸不同部位酒醅理化性质表明地缸中的温度场对白酒发酵产生了影响。由此认为,白酒发酵过程酒醅温度控制技术需以更深入的研究为基础。     

The effect of temperature and ultimate pH on the increase in meat toughness resulting from restraint during cooking

Samples of stretched muscle cooked at 50, 60, 70 or 80°C, while restrained at either their original pre-cooking length or further tensioned at about 130% of their original pre-cooking length, had significantly (P < 0·001) greater Warner-Bratzler (WB) peak shear force values for all temperatures than similar samples cooked without restraint except for those restrained at their original length and cooked at 50°C. Restraint during cooking at 80°C increased the peak shear force values of stretched sheep muscles with ultimate pH values in the range 5·5-7·0. This increase, which has been related to connective tissue strength, was not significantly related to ultimate pH. Both initial yield and peak force values, for samples cooked either restrained or unrestrained, decreased significantly (P < 0·001) and at similar (not significantly different) rates with increase in ultimate pH.     

The effect of DFD classification and internal cooking temperature on certain pork muscle characteristics

The data incorporated in this experiment were gathered from 14 littermate pairs of swine of the same sex differing in weight by <4·5 kg with one animal in each pair subjected to standardized stress. Samples of the Longissimus dorsi (LD) and the Psoas major (PM) muscles were cooked to internal temperatures of 64, 70 and 76°C. The samples of the Quadriceps femoris (QF) muscle were cooked to internal temperatures of 70 and 76°C. DFD classification of the raw muscle was determined by the 48 h pH. Stress produced DFD meat in the PM and QF muscles but not in the LD muscle. DFD muscle required shorter time to reach any of the cooked internal temperatures studied when compared to normal muscle. Slightly-DFD PM muscle more closely resembled the normal muscle in all variables except the panel tenderness score. Cooking DFD PM muscle to an internal temperature 6°C higher than normal muscle caused a reverse in the direction of cooking loss, fiber diameter, tenderness and expressible water when compared to normal and DFD muscle cooked to the same internal temperature. Cooking DFD PM muscle to an internal temperature 12°C higher than normal muscle produced changes associated with increasing the internal temperature of normal muscle. Similar trends, as described for the PM muscle, were observed in the QF muscle.     

Studies on the combined effect of gamma radiation and cooking on the nutritional value of fish

The effect of irradiation (0·6 Mrad), cooking and a combination of both treatments has been measured on the protein nutritive value and on the B-complex vitamins, nicotinic acid, riboflavin and thiamine in cod fish fillets. Microbiological assay methods were used throughout. Protein nutritive value was unaffected by irradiation, whereas cooking caused a 9% loss; this loss was not increased by prior irradiation treatment. Irradiation did not affect nicotinic acid and a 4% loss caused by cooking was again not increased by a combination of treatments. Riboflavin was reduced 6% by radiation, 9% by cooking, and 16% after both treatments, whilst for thiamine the losses were 47% by radiation, 10 % by cooking and 54% by combined treatment. It was concluded that irradiation followed by cooking produced a total loss which was the sum of the losses produced by each treatment. The importance of loss of nutrients in fish due to radiation processing is discussed.     

蒸煮助剂对稻麦草亚硫酸钾蒸煮的作用

研究了新型蒸煮助剂磷酸钾和常规蒸煮助剂蒽醌、CT-1在稻麦草的亚硫酸钾蒸煮中的作用.实验结果表明磷酸钾对稻草和麦草亚硫酸钾蒸煮具有不同程度降低纸浆硬度的作用.蒽醌对于麦草亚硫酸钾法蒸煮有显著作用.而蒽醌和CT-1对于稻草亚硫酸钾法蒸煮没有起到明显作用.     

The effect of microwave and conventional cooking on the temperature profiles and microbial flora of minced beef.

Beef mince samples were cooked to the rare, medium and well done states by microwave and conventional oven methods. The raw samples all contained large numbers of contaminating organisms and low numbers of Listeria monocytogenes were detected in the majority of samples. A substantial proportion of the contaminating flora survived in mince cooked by microwaves to the rare, medium and well done states, prior to a 30-min standing period. Listeria monocytogenes survived in all samples cooked by microwaves to the rare state, prior to the standing period and was still present in one of three after the standing period. It was also detected in one of three samples cooked to medium prior to a standing period. This organism was not detected in mince cooked by conventional oven methods. In all the samples cooked by microwaves with a standing period and samples cooked to rare and medium by conventional oven, survival of some of the microflora occurred. The survival rate decreased with the severity of the cooking treatment.     

碎茶末中超高压提取茶多酚在鱼肉保群中的应用

茶叶在加工和储存过程中不可避免会产生碎茶末,本文采用超高压技术常温提取碎茶末中茶多酚,将其变废为宝.方法是通过正交实验,以茶多酚含量为指标,考察溶剂浓度、压力、保压时间、固液比对茶多酚含量的影响,结果表明,最优提取工艺条件为:乙醇浓度为50%;压力200MPa;保压时间5min;固液比为1:20,得率是37.7%.并将其粗制品应用到鱼肉的保鲜中,实验表明茶多酚粗制品能有效延长鱼肉的保鲜时间.     

The effect of muscle, cooking method and final internal temperature on quality parameters of beef roast

The aim of the study was to evaluate the influence of cooking conditions (dry air and steam) and final internal temperature (75, 85, 95°C) on the physico-chemical properties of beef infraspinatus (INF) and semimembranosus (SEM) muscles as well as their tenderness and juiciness. Cooking method and temperature influenced moisture, total collagen content in cooked meat and cooking loss, whereas muscle type affected fat, total collagen content and cooking loss. Warner-Bratzler shear force values were affected by cooking method, which also influenced juiciness of roasts. Temperature affected tenderness and juiciness, whereas muscle type influenced juiciness. The most desirable tenderness had INF heated in steam and dry air to 95°C. Processing SEM in dry air to 85 and 95°C lowered the juiciness of the roasts. There were significant correlations between physico-chemical, sensorial and image attributes, however high accuracy of prediction (r(2)>0.8) was achieved only for SEM muscle.     

The effect of compression,stretching, and cooking temperature on free oil formation in mozzarella curd

The effect of the extent and rate of compression and stretching on free oil formation in Mozzarella cheese curd was investigated at 55, 65, and 75 degrees C. Confocal laser scanning microscopy was used to determine the maximum cross-sectional diameter, cross-sectional area, elongation factor (maximum divided by minimum cross-sectional diameter), and circularity of fat globules in the cheese curd at the different temperatures, and after stretching or compression. Free oil was not significantly affected by the rate of biaxial compression from 50 to 2000 mm/min at 65 degrees C, the rate of tensile stretching from 1000 to 2500 mm/min at 60 degrees C, or the extent of biaxial compression from 40 to 80% of the original height at 1000 mm/min and 65 degrees C. Increasing the rate of stretching from 1000 to 2500 mm/min increased the elongation factor from 1.91 to 2.61. Cross-sectional area, maximum diameter, and circularity were not affected by the rate of biaxial compression. The extent of curd compression had no effect on the milk fat globule size and shape. Increasing the extent of stretching at 60 degrees C and at 1000 mm/min increased the free oil content (on a fat basis) from 23.8% (curd stretched by 1.4x) to 32.3% (stretched by 4.6x) and the elongation factor of the globules, but did not affect any of the other globule parameters. Increasing the temperature of the cooking-stretching water increased the cross-sectional area, diameter of the globules, and free oil content from 24.1% at 55 degrees C to 34.5% at 75 degrees C for curd compressed to 50% height at 1000 mm/min.     

均质压力及喷雾干燥温度对鱼油微胶囊化的影响

采用辛烯基琥珀酸酯淀粉Hi-Cap100和葡萄糖浆作为鱼油微胶囊的壁材。研究了不同均质压力下乳化液黏度、粒径和粒径分布规律,考察了不同均质压力下乳化液特性与鱼油微胶囊包埋率、表面油含量之间的相关性,探讨了喷雾干燥温度对包埋率和鱼油过氧化值(POV)的影响。研究结果表明,随着均质压力的增加,乳化液黏度和平均粒径逐渐减小,而粒径分布离散度总体呈下降趋势,在40MPa时最小,说明此时粒径分布均一性最佳;喷雾干燥温度增加时,鱼油包埋率先增后减,POV值先减后增,在进/出口温度为140℃/70℃时有最高的包埋率和最低的POV值。通过分析确定最佳工艺参数如下,均质压力为40MPa,喷雾干燥进口温度为140℃,出口温度为70℃。在上述最适工艺条件下,鱼油微胶囊平均粒径为5.97μm,表面油含量为2.03%,微胶囊化包埋率为95.6%,在扫描电镜下观察微胶囊表面和内部结构良好,具有良好的包埋效果。     

马氏珠母贝肉蒸煮液主要呈味成分分析

采用高效液相色谱法、自动氨基酸分析仪、原子吸收光谱等方法分析了马氏珠母贝全脏器、闭壳肌和内脏团蒸煮液的主要呈味物质。结果表明:蒸煮液中游离氨基酸含量丰富,与呈鲜味和甜味相关的天门冬氨酸、谷氨酸、甘氨酸和丙氨酸4种氨基酸含量占到50%以上;ATP及其关联化合物含量中HxR的含量最高;内脏团蒸煮液中甜菜碱的含量最高,达到191.00 mg/100mL;琥珀酸在全脏器和内脏团蒸煮液中的含量较高,分别达到了125.00 mg/100 mL和124.00mg/100 mL;内脏团蒸煮液中糖原含量最高,达到了105.34 mg/100 mL,与呈味有着密切关系的阳离子K+、Na+在3种样品蒸煮液中的含量均较高,而阴离子PO43-在闭壳肌蒸煮液中含量最高、Cl-在内脏团蒸煮液中含量最高。     

Lipid oxidation in salted-dried fish: The effect of temperature and light on the rate of oxidation of a fish oil

In relation to studies of lipid oxidation during the processing and storage of salted sun-dried fish, the measurement of the initial rate of oxygen uptake has been studied on a model system consisting of a highly polyunsaturated fish oil. This parameter has been used for assessing the effects of temperature and light conditions on the model system and has been compared to changes in the peroxide value and the polyene index. Assessment of oxygen uptake using a Gilson respirometer was found to give a clearer indication than other methods of assessment of the effect of different conditions on fish oil oxidation. At 30°C the initial rate of oxygen uptake increased from 0-103 μl O₂, g^?1 miir^?1 to 0-158 μl O₂, g^?1 min^?1 with a change in light conditions from dark to photosynthesis light. At 40°C, the rate of oxygen uptake was fester than at 30 °C, and the effect of light was more pronounced, giving values of 0.188 μl O₂, g^?1 min^?1 and 0.483 μ O₂, g^?1 min^?1, for dark and photosynthesis light, respectively. The observed results for the measurement of the initial rate of oxygen uptake suggest its use as a sensitive and reliable method for the investigation of the contribution of the many components in salted sun-dried fish towards the rate of oxidation and subsequent rancidity.     

香味调料在烹饪中的作用

烹饪加工中常需加香味调料,用以改善或增加菜点的香气,或掩盖原料中的不良气味。烹饪中使用的都是植物性天然香味调料。不同的香味调料使用的民有所不同,所用形态也有所差异。使用香味调料时应根据不同的 同的质量要求和工艺过程来选择,以求获得最佳的风味效果。     

绍兴传统醉鱼干的加工工艺

为传承传统鱼类加工工艺,介绍了传统的绍兴醉鱼干的原料选择、生产工艺流程、原料的处理方法、操作方法和产品的标准.     

The effect of cooking temperature on mechanical properties of whole meat, single muscle fibres and perimysial connective tissue

The structural changes in beef semitendinosus caused by cooking were studied by performing tensile tests of the isolated meat components (i.e. single muscle fibres and perimysial connective tissue) and related to the toughness of the whole meat. Whole meat toughness was found to increase in two separate phases upon cooking from 40-50°C, and again from 60 to 80°C with a decrease in meat toughness between 50 and 60°C, in agreement with previous studies. The changes in whole meat toughness at temperatures below 60°C were found to correspond to changes in the mechanical properties of the perimysial connective tissue, whereas changes of whole meat toughness at temperatures above 60°C were found to correspond to increased breaking strength of single muscle fibres. The myofibrillar component explained approximately 47% of the variation in whole meat toughness upon cooking whereas inclusion of the connective tissue component increased the goodness of fit.     

The effect of cooking on proteins from acha (Digitaria exilis) and durum wheat

The effect of cooking on proteins from acha and durum wheat was assessed from an analysis of protein extractability, gel electrophoretic profiles, in-vitro protein digestibility (IVPD) and the amino acid compositions of wholemeal flour and residue proteins. Heating wholemeal flour samples at 100–140°C (t = 10–40 min) resulted in 0–30% and 45–55% decreases in acha and durum protein solubility, respectively. In general, high molecular weight (30–70 k Da) protein subunits were more susceptible to heat damage. For both cereals, sodium dodecyl sulphate (SDS; 10 g litre^?1) and/or dithiothrcitol (DTT; 10 mM ) increased protein solubility in unheated and heated samples. The IVPD index was 90–91% and was not significantly altered by cooking (100–120°C, t = 40 min). Cooking at extreme temperatures (140°C, t = 40 min) reduced the IVPD by 8% (P = 0.05). Osborne fractionation resulted in a durum or acha residue level of 7.8% or 55.2%. Treatment with solvent containing propanol, SDS and/or DTT at room temperature followed by SDS-polyacrylamide gel electrophoresis of non-solubilised proteins showed that the glutelin fraction of acha, with the exception of a 65 kDa subunit, was insoluble owing to strong inter-subunit hydrophobic and disulphide interactions. Wholemeal acha flour and residue protein showed a significantly greater level of hydrophobic and sulphur amino acids as well as glutamine which is associated with H-bonding. The possibility that cereal protein solubility is also dependent on protein-carbohydrate links is discussed.     

The effect of cooking conditions on the eating quality of pork

Two experiments were conducted to examine the effects of cooking parameters, including final internal temperature (65, 72·5 or 80°C), on the eating quality of pork. Assessments were made by a 10-member trained taste panel. In Experiment 1 on loin steaks (m. longissimus) from 28 carcasses weighing 66 ± 1·9 (SD) kg, increasing the final internal temperature from 65 to 80°C had the following effects on mean scores (1-8): tenderness -1·0; juiciness -1·5, pork flavour +0·6 and abnormal flavour -0·5. The medium temperature of 72·5°C was suggested as ideal. In Experiment 2 on leg roasts (m. gluteobiceps) from 96 carcasses weighing 65 + 2·7 (SD) kg, increasing the final internal temperature from 65 to 80°C had the following effects on mean scores (1-8): tenderness -0·2 (not significant), juiciness -0·6, pork flavour +0·3 and abnormal flavour -0·5. The effects of final internal temperature were therefore smaller in roasts and temperatures towards the upper end of the range would be recommended for ideal eating quality, balancing small losses in tenderness and juiciness against gains in flavour scores. Although the experiments were not designed to examine source and sex effects there was evidence that tenderness can be improved through the use of Duroc genes and pelvic suspension of carcasses and no evidence of differences in eating quality between entire males and females.     

用碱量对烧碱法麦草浆蒸煮的影响

麦草原料制浆的主要方法是烧碱法,烧碱在蒸煮过程中起着脱除木素的作用,粗浆硬度一般随着用碱量的提高而降低。为了深度脱木素,一味地提高用碱量是否会使木素的含量和粗浆硬度一直降低下去？通过研究证明,烧碱的作用是有限的,当用碱量提高到一定程度时,粗浆硬度曲线下降的趋势变得非常平缓,脱木素非常困难,几乎成一直线。     

The effect of cooking on Brassica vegetables

Assessing antioxidant intake requires a food antioxidant database. However, cooking may affect antioxidant content due to antioxidant release, destruction or creation of redox-active metabolites. Here, effects of boiling, steaming and microwaving of broccoli, cauliflower, cabbage and choy-sum (Chinese cabbage) were explored by measuring antioxidant contents of raw and cooked vegetables. Cooking water was also tested. For all cooked vegetables, antioxidant content was highest in steamed > boiled > microwaved, and decreased with longer cooking time, regardless of method. All steamed vegetables had higher antioxidant contents than had matching raw vegetables. Effects were variable for boiling and microwaving. Microwaving caused greater antioxidant loss into cooking water than did boiling. Marked losses of anitoxidants occurred in microwaved cabbage and spinach. To assess food antioxidant content/intake accurately, cooking effects need detailed study. Steaming may be the cooking method of choice to release/conserve antioxidants. The cooking water is a potentially rich source of dietary antioxidants.