Effects of boning method and postmortem aging on meat quality characteristics of pork loin

This work investigated the effects of boning method and postmortem aging on pork loin color, shearing value and sensory attributes. Two experiments were assigned. In Experiment I, 30 Chinese native black pigs were slaughtered and their carcasses were divided into three groups: (i) hot-boning: carcasses were fabricated within 45 min postmortem just after dressing; (ii) cold boning at 24 h: carcasses were fabricated after chilling at 0°C for 24 h; (iii) cold boning at 36 h: carcasses were fabricated after chilling at 0°C for 36 h. In Experiment II, right sides of the second group in Experiment I were used and primal cuts were vacuum packed and aged for 1 day, 8 days and 16 days. Pork loins ( Longissimus lumborum ) were used for color measurement, shearing test, and sensory evaluation. Among three boning methods, cold-boning at 36 h postmortem had the advantages of giving muscles a better color, the lowest cooking loss and cooked shearing value, and the highest sensory tenderness, juiciness, flavor and overall liking. Postmortem aging could improve pork quality characteristics, but it is not the fact that the longer aging time is, the better pork quality would be. Eight days may be enough to obtain an acceptable sensory attribute. These results are meaningful for pork processing and pork consumption.     

The influence of aging and low zinc nutrition on the choroid in the pig: I. The melanocyte

The effects of low zinc nutrition and aging on central choroidal melanocytes were examined in the pig. Three populations of pigs (young, pregnant and aged), were maintained on either control (C) or low zinc (LZ) diets. Twenty-five weanling boars were sacrificed at 2, 4, 8, 10, and 12-month intervals, and nine pregnant sows and eight aged sows were sacrificed after a 6-month interval. Melanocytes of the central choroid were morphologically and morphometrically examined. The melanocyte was found to be conservative in its form, which was mostly elliptical longitudinal profile, throughout the different age populations that were fed the C diet. Morphometric observations revealed that this cell type increased in size in the oldest animals, having been 40% greater than that in the younger two populations. However, the overall percentage area occupied by melanocytes remained the same throughout all age groups. In the animals that were fed the LZ diets, a large subpopulation of choroidal melanocytes was oval to round in shape in the pregnant and aged groups. Many members of this subpopulation possessed less opaque pigment than the elliptically shaped cell. Measurements of the size and percentage area occupied in these oldest groups increased significantly. In addition to the change of size, shape and melanin opaqueness, unusually large melanosomes were consistently observed in the pregnant and aged LZ groups. Low zinc nutrition had a remarkable age-related impact on the usually quiescent melanocyte.     

The influence of aging and low zinc nutrition on the choroid in the pig: II. The melanosome

The effects of low zinc nutrition and aging on central choroidal melanosomes were examined in the pig. Melanosomes of central choroidal melanocytes were morphologically and morphometrically examined in three populations of pigs (young, pregnant and aged), that were maintained on either control (C) or low zinc (LZ) diets. In C groups, the typical melanosomes decreased in size with age, although a subpopulation of larger melanosomes occurred in the oldest group. In contrast, the melanosomes of the animals on LZ diets increased in size significantly in the adult groups. The melanosomes in the pregnant and aged groups were 65% and 30–40% greater than those of the age-matched C groups. Extremely large melanosomes were frequently encountered in adult LZ choroidal melanocytes. Melanogenesis of these large bodies included the formation of one or more outer shells. Fusion of adjacent large melanosomes was also observed. Melanolysosomal-like bodies were observed, particularly among the pigmented cells in the large blood vessel region of C and LZ adults. Melanin dynamics, i.e. its production and breakdown, occurred within choroidal melanocytes throughout much of the lifespan of the pig. This dynamic was greatly influenced by low zinc nutrition, resulting in unusual and aberrant melanin activity.     

积极老龄化背景下安徽省养老服务政策研究——基于2002—2022年政策文本的分析

在积极老龄化背景下,推动养老服务政策优化升级是新时代老龄社会治理的迫切需要。运用文献计量法和内容分析法,从外部要素和内在属性两方面,对安徽省2002-2022年39份政策文本进行综合量化研究发现,养老服务政策发展历经三个时期;发文主体之间是跟随型府际关系与协作型府际关系并存的合作模式;养老服务政策可执行性和可操作性有待加强;“老有所养”“老有所医”是养老服务政策核心;养老服务政策工具使用结构失衡。未来制定养老服务政策要坚持问题导向,加强协作配合;强化需求认识,拓展需求空间;健全政策工具协调网络,规划合理工具组合方式。     

适老化背景下的街道景观改造研究——以南京市溧水区晶桥镇为例

通过对适老化小镇的景观改造研究,从康养人群对街道景观的体验需求、生活需求、审美需 求等方面出发。以南京市溧水区晶桥镇街道景观为例,通过分析街道景观改造中各方面的影响,对如 何营造功能合理、符合康养人群生活特点的街道环境,如何重塑旧街道景观的新定位提出建设性意 见。     

人工老化处理大麦种子的活力和生理生化特性

为探索大麦种子老化过程中种子活力与生理生化的变化情况,指导大麦种子的合理贮藏,通过人工老化处理（45℃,90％RH 高温高湿）大麦种子,对其种子发芽指标、相对电导率、可溶性糖、可溶性蛋白、POD 和 CAT 活性、丙二醛含量等生理生化指标进行测定。结果表明：1）随着老化进程加剧,大麦种子的相对电导率、可溶性糖、丙二醛含量逐渐升高,发芽势、发芽率、发芽指数、活力指数、可溶性蛋白、POD 和CAT 活性逐渐降低。2）在大麦种子的老化过程中,生理生化指标变化均与种子的老化及劣变密切相关,其中发芽势、发芽率、发芽指数、活力指数、可溶性蛋白含量、POD 和 CAT 活性与种子活力下降的趋势相同。     

种子的劣变及劣变原因的研究

长期以来，人们就知道种子劣变的现象，由于种子劣变与种子寿命及种子活力和萌发力的密切关系，近年来这方面的研究日益增多，虽然人们已普遍承认种子劣变是一不可避免和不可逆的变化，尚无人指出为什么如此，本文分析了种子劣变的机理，讨论了种子劣变的原初原因。     

人工加速老化处理对小麦种子生理生化特性的影响

为探明小麦种子贮藏过程中的生理生化变化及种子活力下降的主要原因,采用高温高湿人工加速老化的方法,在90%RH(相对湿度)和55℃条件下对非糯小麦及糯小麦种子进行老化处理,测定其发芽率、电导率、丙二醛含量、可溶性糖含量、SOD、POD、CAT活性和可溶性蛋白质含量的变化.结果表明,种子发芽率随老化处理时间的延长而逐渐降低,且在相同处理时间下非糯小麦种子的发芽率都高于糯小麦;种子浸出液电导率则随处理时间延长呈微升趋势,在整个处理过程中非糯小麦种子浸出液电导率均低于糯小麦;非糯小麦POD活性、SOD活性总体上明显高于糯小麦种子,而可溶性糖、可溶性蛋白质和丙二醛含量则低于糯小麦.非糯小麦种子的抗老化能力显著强于糯小麦种子.     

改性粘土对天然橡胶／粘土复合材料抗氧老化性能的影响

采用高分子包复剂、硅烷偶联剂、钛酸酯偶联剂，并结合使用氧剂对粘土进行改性处理，制备相应的粘土胶进行热氧老化、光氧老化及臭氧老化性能测试。结果表明，高分子包复剂、抗氧剂及偶联剂产生协同作用；大大提高了粘土胶抗热氧老化及光氧老化性能，而新型胺类防老剂与钛酸酯偶联剂共同使用，可使粘土胶抗臭氧老化性能提高50%。     

论撒切尔政府养老金制度改革的动因

在英国养老金制度发展史上, 1986 年的撒切尔政府养老金制度改革是一次具有重要意义的改革。促成这次改革是多种因素的综合: 人口老龄化使养老金支出不断增长; 社会保障制度发展与经济发展水平之间的不协调; 养老金制度本身的缺陷; 哈耶克的思想和货币主义理论对撒切尔的巨大影响; 政界的右转。