THE EFFECT OF THERMOCOUPLE AND RECEPTACLE TYPE ON OBSERVED HEATING CHARACTERISTICS OF CONDUCTION-HEATING FOODS PACKAGED IN SMALL METAL CONTAINERS

Three different types of thermocouples and receptacles were studied to determine the effect on the observed heat penetration rate of a conduction‐heating food packaged in 202 × 204 and 211 × 300 cans. The studies were conducted at two product initial temperatures (70 and 140F) and three retort temperatures (240, 250 and 260F) using an Allpax R&D retort. The results indicated that the Ecklund stainless steel receptacles and needle type thermocouples in 202 × 204 cans increased the apparent heat penetration rates significantly, which resulted in underestimated Ball Formula process times (≈5%) and overestimated process lethalities (≈27%). However, in the 211 × 300 cans only minimal effects were seen on the apparent heat penetration rates, Ball process times and resulting lethalities. The use of plastic Delrin receptacles and thermocouples in 202 × 204 and 211 × 300 cans produced results in close agreement with those obtained from thin‐gauge flexible thermocouples having minimum conduction error.     

谷氨酰胺转氨酶对猪肉糜失水率和硬度影响的研究

研究了谷氨酰胺转氨酶对猪肉糜保水性及对猪肉糜糕弹性的影响。结果表明最佳作用添加量为0.45%、最佳作用温度为35℃、最佳作用时间为2.0h;辅料大豆蛋白GsNa、大豆蛋白EGP和大豆蛋白HTP对谷氨酰胺转氨酶作用影响结果表明添加4%的大豆蛋白GsNa和添加0.1%的大豆蛋白EGP能显著改善猪肉糜的保水性及猪肉糜糕的弹性,而大豆蛋白HTP对其影响则不明显。     

影响废纸油墨可脱除性的因素

影响废纸油墨可脱除性的因素很多,既与废纸及印刷油墨的种类及特性、废纸的贮存状况等有关,也与所采用的脱墨方法、工艺流程及工艺条件密切相关。该文对影响油墨可脱除性的各种因素进行了详细论述。     

THE EFFECT OF LACTIC ACID DECONTAMINATION ON THE MICROFLORA ON MEAT

Meat acquires a characteristic microflora after slaughter and butchering. This normal microflora may be beneficial in that it occupies a niche that would otherwise permit unimpeded growth of potential pathogens. Lactic acid decontamination (LAD) is intended to eliminate pathogens but also affects the normal microflora. The immediate effect was studied by means of an in-vitro model. Experiments using this model achieved a reduction in the mesophilic Enterobacteriaceae on meat by 1 to 3 log₁₀ colony forming units and shifted the predominant microflora in the direction of Gram-positive bacteria and yeasts. Colony counts were an unreliable indicator of LAD-induced reductions in Gramnegative foodborne pathogens. Their reduction depended on the ratio of the more lactic acid resistant Gram-positive bacteria to the more sensitive Gram-negative bacteria. The rank order of lactic acid-resistance of nonpathogens present on meat was yeasts = lactobacilli > psychrotrophic Gram-positive bacteria > mesophilic Enterobacteriaceae. Psychrotrophic Gram-negative bacteria were the most sensitive.     

OBSERVATIONS ON THE EFFECT OF LIPIDS ON HEAD RETENTION

Modification of the conventional method of filtering an infusion mash was found to increase the content of extractable head-negative substances, including phospholipids, in unhopped wort. The additional constituents were also present in the corresponding hopped worts and in beers at rack but largely disappeared during subsequent processing. Much of the additional fatty material was removed when finings were added: this process induced a substantial rise in head retention. The positive role of lipids in brewing processes is discussed.     

助剂对苎麻脱胶的影响

对苎麻脱胶进行了小试,研究了其化学组成及脱胶对苎麻的影响,筛选出一种独特有效的煮炼助剂,并结合生产实际,证明其碱煮炼脱胶效果相当明显。     

环境因素对印刷的影响

本文概述了环境因素对印品质量和印刷工艺过程的影响情况,从温湿度、照明、车间布局等方面探讨了这些因素的作用及其机理,并列举了改进和控制方法,给出了推荐的环境参数。     

全脂大豆蛋白对面条品质影响的探讨

通过在面粉中添加不同比例的全脂大豆蛋白，探讨了其对蛋白质品质、面团流变学特性、面条色泽、断条率、咀嚼感、爽口感及面条蒸煮品质和感官品质的影响。结果表明，在面粉中加入8％的全脂大豆蛋白可显著提高面粉的蛋白含量和湿面筋含量，改善了面团的流变学特性及面条的韧性和口感，既增加了面条营养价值，又提高了面条的质量和加工性能。     

THE EFFECT OF FUMIGANTS ON FOOD QUALITY

Fumigants are used to prevent pest infestations in food and other stored commodities. The quality of the commodity may be affected by fumigant treatment in several ways. Residues of unchanged fumigant may remain in the commodity. Reaction of the individual chemical components of the commodity with the fumigant may alter its chemical or physical properties, thus resulting in changes in flavor, taste, odor, nutritional value or processing qualities. Methyl bromide, ethylene dibromide, ethylene dichloride, carbon tetrachloride, phosphine and ethylene oxide are the major fumigants used for treatment of grains, vegetables and fruits. Their effects on food quality and the significance of residues in treated commodities are reviewed.     

THE EFFECT OF ABRASION ON DORMANT BARLEY

The primary purpose of barley abrasion is to facilitate the passage of gibberellic acid to the aleurone tissue, particularly at the distal end of the grain. Abrasion has now been shown to alleviate dormancy as a result of the damage suffered by the proximal areas of the barley grain during the abrasion treatment. This effect alone should make the abrasion process useful to the malting industry whether or not subsequent treatment with gibberellic acid is desired, particularly when multi-hit rather than single-hit abrasion machines are used.     

植物复合抗疲劳饮料的研究

以开发抗疲劳保健饮料为目的,采用天然保健原料配制成植物抗疲劳饮料.对该饮料的配方、生产工艺流程、技术操作要点、风味进行了讨论,提出了较为合适的方案:原料提取液经过处理后,以提取液36%,白砂糖9%,柠檬酸0.08%,香精0.01%配比为佳.采用运动生化常用的手段做抗疲劳试验.结果表明该饮料能显著提高实验小白鼠的抗疲劳能力.     

钙离子对腐竹生产的影响研究

利用乳酸钙的营养强化作用和明显的促进蛋白质凝胶形成的架桥作用,在腐竹生产中添加乳酸钙后,可以明显增加钙含量并促进腐竹膜的形成.研究结果显示,添加乳酸钙后腐竹中的钙含量直线增加,当乳酸钙添加量为豆浆质量的0.7 g/kg～1.1 g/kg时,腐竹的产量和形成速度分别增加12%～22%和12%～29%.同时,腐竹的最佳形成温度降低1.5℃～4.5℃.     

STUDIES ON THE EFFECT OF TEMPERATURE ON THE MOISTURE SORPTION CHARACTERISTICS OF POTATOES

An understanding of the moisture sorption characteristics of food systems is an important objective in food engineering, in particular with respect to the mass transport phenomena during drying. A standard gravimetric technique was employed to examine the influence of temperature on the adsorption and desorption behavior for potatoes. The type II sorption isotherms were analysed using the Guggenheim-Anderson-de Boer model, with the observed hysteresis phenomena displaying a temperature dependence. The moisture dependent net isosteric heats of sorption were determined using the Clausius-Clapeyron equation.     

凝乳pH值对Mozzarella干酪质量及出品率的影响

分别设计6．4、6．2、5．9、5.5、5．2、5．0、4．7、4.0、3．3等9个pH值,比较系统地研究凝乳pH值对Mozzarella干酪质量和出品率的影响。结果表明,凝乳pH值对Mozzarella干酪的质量和出品率影响很大,凝乳pH值控制在5．2左右时,Mozzarella干酪的质量和出品率都比较理想。     

EFFECT OF THE REDOX POTENTIAL ON THE MUSCLE ENZYME SYSTEM

ABSTRACT This work presents the effect of redox potential in the range +100 to ?250 mV on the muscle cathepsins B, H and L, lysosomal acid lipase and acid esterase and on neutral and basic lipases and neutral esterase from adipose tissue. Cathepsins B, H and L need reducing conditions (below ?50 mV) for maximal activity. Lysosomal acid lipase remains unaffected while activity of muscle acid esterase decreases sharply below ?175 mV. The activity of basic lipase from adipose tissue is also reduced below ?80 mV while neutral lipase remains unaffected. The activity of neutral esterase is drastically reduced to negligible values below ?100 mV.