不同包装方式对贮藏牛肉食用品质的影响

实验以延边黄牛腿肉为实验对象,采取托盘包装、真空包装和热收缩包装,(4±1)℃冷藏,通过检测蒸煮损失、pH、剪切力、表面颜色,研究不同包装方式对贮藏期间牛肉品质的影响。实验结果表明:贮藏时间和包装方式对延边黄牛肉品质影响显著(p<0.05),真空包装牛肉的pH上升速率较慢,表面颜色的稳定性好,真空包装保鲜效果最好,保质期可达21d,热收缩膜包装的牛肉保鲜效果次之,保质期为18d,而托盘包装的牛肉保质期仅为12d。      

不同注水量对猪肉食用品质的影响

通过研究不同注水量(0、10%、20%、30%、40%)对猪肉色泽、pH、剪切力、滴水损失、蒸煮损失、压榨损失、离心损失、贮藏损失、拿破率的影响,比较分析正常猪肉与不同比例注水猪肉食用品质的差异。结果表明:随着注水量的增加,L^*、b^*、滴水损失、蒸煮损失、压榨损失、离心损失、贮藏损失显著增大(p<0.05),a^*、剪切力随着注水量的增加显著减小(p<0.05);当注水量小于20%时,注水猪肉的L^*、压榨损失、贮藏损失、离心损失与正常猪肉差异显著(p<0.05),而当注水量大于等于20%时,注水猪肉的L^*、a^*、压榨损失、贮藏损失、离心损失、剪切力值、蒸煮损失、滴水损失均与正常猪肉存在显著性差异(p<0.05)。与正常猪肉相比,注水后的猪肉亮度增加,保水性变差,嫩度有所增加。相关性分析表明,注水后肉块保水性的变化影响色泽的改变,同时也会影响嫩度的变化。     

贮藏温度对气调包装白切鸡保鲜效果的影响

为研究不同贮藏温度对气调包装(30% CO₂/70% N₂)白切鸡货架期及品质的影响,将样品分别置于4、7℃以及12℃下贮藏0~7 d,隔日测定微生物含量、pH、色度、贮藏损失、离心损失、挥发性盐基氮(TVB-N)及感官品质。结果表明,与7℃和12℃条件贮藏相比,4℃条件白切鸡贮藏期间,微生物含量最低,pH上升缓慢,贮藏损失最低,TVB-N生成量减缓,感官评分最高。白切鸡的亮度值(L^*)及黄度值(b^*)在贮藏期间显著降低(p < 0.05),贮藏温度对色度值的影响不显著(p > 0.05)。根据菌落总数及感官评定结果可知,白切鸡在4、7和12℃条件下货架期分别可达到7、6和4 d。因此,4℃贮藏能有效延长气调包装白切鸡的货架期,减少贮藏期间鸡肉食用品质的劣变。     

辅料黏合剂的添加对调理猪排品质的影响

以猪颈背肉为主要原料,研究转谷氨酰胺酶(TG)、酪蛋白酸钠(SC)、复配胶(卡拉胶和魔芋胶1:1)对调理猪排品质的影响。通过单因素实验,研究转谷氨酰胺酶、酪蛋白酸钠、复配胶的添加对调理猪排剪切力、离心损失、蒸煮损失、水分含量、色差、出品率、感官评分的影响。在单因素实验的基础上,进行响应面试验,确定粘合剂的最优添加量。单因素结果表明,TG添加量为0.60%时,保水性及感官评分最高,酪蛋白酸钠添加量为0.10%,或复配胶(卡拉胶和魔芋胶1:1)添加量为0.20%时,既能保证适宜的嫩度与保水性,感官评分也最高。响应面试验结果表明,在转谷氨酰胺酶添加量为0.70%、酪蛋白酸钠添加量为0.07%、复配胶添加量为0.21%时,所加工的调理猪排的感官评分最高,总分60分时,得分为55.54。     

牦牛肉品质特性研究进展

牦牛肉是我国青藏高原的重要畜牧产品之一,在当地居民的膳食及高原地区的经济发展中占据重要地位。了解牦牛肉的肉质特性对于牦牛肉的精深加工和牦牛资源的合理开发有重要意义。本文综合近几年国内外相关研究,从营养品质、食用品质和加工品质3个方面对牦牛肉的品质特性进行概述和分析,以期为牦牛肉的品质改善和产品开发提供参考和思路。牦牛肉营养价值高、绿色无污染、市场潜力大,但嫩度较差,今后需借助适当饲养方式和宰后处理方式对其嫩度进行改善。     

蒸汽辅助烤制技术 在肉类烹饪中的应用

随着蒸烤箱的快速发展,蒸汽辅助烤制技术被广泛应用在肉类食材加工中。蒸汽在高温烤箱中的引入改变了腔体中的传热状态,对食物质构特性产生复杂的影响,降低了烤肉的外观接受度,但具有减油减盐和减少有害物质产生的功能,可以提高肉品的健康性及安全性。因此,本文针对蒸汽辅助烤制的传热特性、对畜禽肉食用品质的影响以及蛋白氧化和杂环胺的生成等方面进行了详细的阐述。蒸汽辅助烤制作为一种新型加热技术,将对家庭烹饪和食品工业的发展产生重要作用。     

Healthier eating: Covid-19 disruption as a catalyst for positive change

Healthy and sustainable diets are necessary for global development goals, but people struggle to modify their eating behaviours which are often habitual and resistant to change. However, disruption can provide the impetus for change, and in the present research we view the Covid-19 pandemic as a potential catalytic disruption with the potential to induce positive behaviour change. Data were obtained from ~900 USA adults, of which 44% self-reported to have made positive dietary change/s. Those who did so tended to be younger rather than older and with higher educational attainment. They also were less food neophobic than people who did not make positive change/s and placed greater importance on health as a motive of daily decisions about what to eat and drink. The contribution of psychographic variables in differentiating between groups of people who did / did not make positive changes once again show their importance in uncovering and explaining the complex factors that motivate food-related consumer behaviour. It seems this holds also when daily lives are disrupted by unforeseen events.     

Ensiled pulp from biorefining increased milk production in dairy cows compared with grass–clover silage

The objective of the current study was to examine the effect of fibrous pulp and partial substitution of soybean meal with green protein concentrate from biorefining of grass–clover on dry matter intake, milk production, digestibility, and eating behavior in dairy cows compared with untreated grass–clover silage and soybean meal. Biorefining of grass–clover occurred right after harvest in a production-scale twin-screw press. The twin-screw pressing separated the grass–clover into a pulp and a green juice. The green juice was fermented using lactic acid bacteria for protein precipitation and then decanted, and the precipitate was heat dried to constitute the green protein concentrate. From the same field, grass–clover was harvested 6 d later due to rainy weather and was prewilted before ensiling. The pulp and the grass–clover were ensiled in bales without additives. The production trial consisted of an incomplete 6 × 4 Latin square trial (3-wk periods; 12 wk total) including 36 lactating Holstein cows. The trial had 6 treatments in a 2 × 3 factorial design with 2 forage types (grass–clover silage and pulp silage) and 3 protein treatments (low protein, high protein with soybean meal, and high protein with a mixture of soybean meal and green protein). The trial was designed to test silage type, protein type, protein level, and the interaction between protein level and silage type. The forage:concentrate ratio was 55:45 in low protein total mixed rations (TMR) and 51:49 in high protein TMR. Low protein and high protein TMR were composed of 372 and 342 g/kg of DM of experimental silages, respectively, and green protein supplemented TMR was composed of 28.5 g/kg of DM of green protein. Silage type did not affect dry matter intake of cows. The average energy-corrected milk yield was 37.0 and 33.4 kg/d for cows fed pulp silage and grass–clover silage, respectively, resulting in an improved feed efficiency in the cows receiving pulp silage. Milk fat concentration was greater in milk from cows fed pulp silage, and milk protein concentration was lower compared with milk from cows fed grass–clover silage. The in vivo digestibility of crude protein and neutral detergent fiber was greater for pulp silage diets compared with grass–clover silage diets. Eating rate was greater, whereas daily eating duration was lower, for pulp silage diets compared with grass–clover silage diets. The partial substitution of soybean meal with green protein did not affect dry matter intake, milk yield, or eating behavior. The in vivo digestibility of crude protein in green protein supplemented diets was lower compared with soybean meal diets. The results imply that extraction of protein from grassland plants can increase the value of the fiber part of grassland plants.     

Liking for foods high in salt and fat is associated with a lower diet quality but liking for foods high in sugar is not – Results from the PREDISE study

The research aimed at examining how liking for foods high in salt and fat and for foods high in sugar are associated with overall diet quality and how these associations differ according to individual characteristics (i.e., sex, age, education, income, nutrition knowledge, and energy reporting status) in French-speaking adults from the Province of Quebec, Canada. As part of the web-based cross-sectional PREDISE study, 1096 men and women completed online questionnaires. The Food Liking Questionnaire assessed reported liking for a variety of salty foods (high in salt and fat) and sweet foods (high in sugar and either high-fat or low-fat) on a scale from 1 to 9. The Canadian Healthy Eating Index (C-HEI) was computed based on data collected using 24-hour food recalls. Women (vs. men) reported lower liking for salty foods (5.97 ± 1.34 vs. 6.58 ± 1.16, p < 0.0001) and for sweet foods (5.52 ± 1.36 vs. 5.71 ± 1.25, p = 0.015). Multiple linear regressions showed that liking for sweet foods was not associated with C-HEI (B = −0.10, p = 0.78). Given a significant sex interaction in the association between liking for salty foods and C-HEI (p interaction = 0.0218), subsequent analyses were stratified by sex. Multiple linear regressions supported that liking for salty foods was more strongly inversely associated with C-HEI in men (B = −3.37, p < 0.0001) than women (B = −1.46, p = 0.0035). In conclusion, a strong liking for salty foods may interfere with healthy eating, especially in men. Building on these results, future studies should investigate the potential of interventions designed to improve the healthiness of food habits in individuals with strong liking for these foods.     

Review of Experiential therapies for eating disorders.

Reviews the book, Experiential therapies for eating disorders, edited by Lynne M. Hornyak and Ellen K. Baker (see record 1989-97569-000). In this book, Lynne Hornyak and Ellen Baker provide a collection of chapters describing "experiential" therapies for eating disorders. Hornyak and Baker define experiential therapy as '...treatment techniques, based on psychological principles that are developed and used with the specific intention of increasing clients' present awareness of feelings, perceptions, cognitions, and sensations; that is, their in-the-moment experience..." (p.3). The book is divided into two sections: The first part addresses the treatment of bulimia nervosa; the second deals with anorexia nervosa. Each author presents his or her treatment approach in sufficient detail to give the reader a clear picture of how the technique could be implemented in the clinical setting. This book may stimulate practitioners to consider the theoretical rationale of their clinical methods and to consider alternative therapies in their treatment of patients with eating disorders. However, the book fell short of the mark in several respects. First, although the authors of each chapter attempted to emphasize the interrelationship of theory and practice, they often glossed over the fact that there was little or no empirical support for either their conceptualiztion of the disorder or the efficacy of the intervention that they espoused. Second, the editors failed to provide the reader with an integrative summary. There was no attempt to provide the practicing clinician with a guide to decision making in the treatment of eating disorders. The editors did not address key questions such as how one assesses a patient with an eating disorder or how one decides which treatment is best suited for her. A related shortcoming is that the editors do not provide the reader with a summary of the state of the art with regard to the conceptualization and treatment of eating disorders. There is now sufficient empirical literature to support specific models of etiology and the efficacy of particular interventions (cf. Brownell & Foreyt, 1986). Without an overview, the reader is left with the impression that the current understanding and treatment of eating disorders is in a prescientific state and that personal preferences rather than empirical findings dictate which treatments are best suited for particular patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)