Ianni Andrea, Martino Camillo, Innosa Denise, Bennato Francesca, Grotta Lisa, Martino Giuseppe
Faculty of BioScience and Technology for Food, Agriculture and Environment, University of Teramo, Via Renato Balzarini 1, 64100 Teramo, Italy.
Department of Veterinary Medicine, University of Perugia, Via S. Costanzo 4, 06126 Perugia, Italy.
Asian-Australas J Anim Sci. 2020 May;33(5):825-835. doi: 10.5713/ajas.19.0155. Epub 2019 Aug 3.
The aim of the present study was to investigate the effect of dietary zinc supplementation of Friesian cows on chemical-nutritional and aromatic properties of Caciocavallo cheese after 7 days (C7) and 120 days (C120) of ripening.
Twenty eight Friesian cows, balanced for parity, milk production and days in milk, were randomly assigned to 2 groups. The control group (CG) was fed with a conventional complete diet, while the experimental group (zinc group, ZG) received a daily zinc supplementation of 60 mg for kg of dry complete feed. During the experimental period, the milk yield was monitored and samples of milk and caciocavallo cheese were collected and analyzed for chemical-nutritional composition and aromatic profile.
The enrichment of dairy cows diet with zinc, did not influence milk yield and composition, however a marked reduction of somatic cell count was evidenced. Both in milk and cheese the ZG samples were characterized by a lower concentration of satured fatty acids and an increase in oleic, vaccenic and rumenic acids. The aromatic profile of dairy products was also positively affected by dietary zinc intake, with an increase in concentration of carboxylic acids, esters and lactones.
The present results suggest a positive role of dietary zinc intake in improving the quality of bovine milk and related cheese, in particular for the increase in concentration of bioactive fatty acids such as rumenic acid. The changes evidenced in cheese through the analysis of the volatile profile, would be consistent with the development of interesting organoleptic properties, although further evaluations should be performed to confirm the consumer acceptability of these changes.
本研究旨在调查给弗里西亚奶牛补充膳食锌对成熟7天（C7）和120天（C120）的卡乔卡瓦洛奶酪化学营养和香气特性的影响。
28头弗里西亚奶牛，按胎次、产奶量和泌乳天数进行均衡，随机分为2组。对照组（CG）饲喂常规全价日粮，而实验组（锌组，ZG）每千克干全价饲料每日补充60毫克锌。在实验期间，监测产奶量，并采集牛奶和卡乔卡瓦洛奶酪样本，分析其化学营养成分和香气特征。
奶牛日粮中添加锌，对产奶量和成分没有影响，但体细胞计数明显降低。在牛奶和奶酪中，ZG组样本的特点是饱和脂肪酸浓度较低，油酸、反式vaccenic酸和反式rumenic酸增加。乳制品的香气特征也受到膳食锌摄入量的积极影响，羧酸、酯类和内酯类浓度增加。
目前的结果表明，膳食锌摄入在改善牛奶及相关奶酪质量方面具有积极作用，特别是对于增加生物活性脂肪酸如反式rumenic酸的浓度。通过挥发性成分分析在奶酪中发现的变化，与有趣的感官特性的发展相一致，尽管还需要进一步评估来确认消费者对这些变化的接受程度。
