Januś Ewa, Sablik Piotr, Jakubowska Małgorzata, Wróbel Klaudia
Laboratory for Organic Production of Food of Animal Origin, Institute of Animal Breeding and Biodiversity Conservation, University of Life Sciences in Lublin, Poland.
Department of Ruminant Science, Faculty of Biotechnology and Animal Husbandry, West Pomeranian University of Technology, Szczecin, Poland.
Vet World. 2021 Nov;14(11):3038-3047. doi: 10.14202/vetworld.2021.3038-3047. Epub 2021 Nov 29.
Curd cheeses are characteristic elements of the dairy assortment, mainly in Central and Eastern European countries, and constitute a numerous and diverse group of dairy products. The aim of the study was to assess the physicochemical, microbiological, and sensory quality of curd cheeses available in marketplaces in Lublin, where they were purchased through direct sales from producers.
The research material was household-produced curd cheese purchased 4 times (at 2-week intervals) from three producers. The physicochemical parameters (i.e., the total protein and fat content, active acidity, and titratable acidity) were determined in the cheeses. Microbiological assays were performed to evaluate the total number of bacteria (on milk agar), the number of yeasts and molds (on Sabouraud medium), and the number of coliform bacteria (on MacConkey medium). A general sensory evaluation was performed by a five-person panel, who assessed the appearance and color, texture, flavor, and aroma of the samples.
The cheeses exhibited significant differences in their protein and fat contents, but these values were within the allowable limits. Most of the evaluated cheeses had normal levels of active and titratable acidity; substantially lower titratable acidity and higher pH values were detected only in the samples from supplier A. The total number of bacteria in the curd cheese samples was high (3.2×10 colony-forming units [cfu]×g cheese) and varied substantially (from 3.6×10 to 8.6×10 cfu×g). The growth of Gram-negative bacterial colonies on MacConkey medium was observed in the samples from suppliers B and C (5.5×10 and 1.7×10 cfu×g, respectively), which is an undesirable phenomenon. The number of colonies cultured on Sabouraud medium and identified as yeast-like microorganisms ranged from 1.8×10 (product from supplier A) to 4.9×10 cfu×g (cheese from supplier C). The scores in the sensory evaluation of the tested curd cheeses were low. The highest mean scores were achieved for appearance and color (4.25-4.45 points). Conversely, flavor and aroma received the lowest score (3.17 points). The highest scores for both the overall assessment and each parameter separately were awarded to the curd cheese produced by supplier A.
Our results suggest poor hygienic conditions during milk collection and processing, as well as during the distribution of these dairy products. Altogether, the purchase of products from direct sales may be associated with risks related to poor consumer health and food quality.
凝乳奶酪是乳制品分类中的特色产品，主要在中欧和东欧国家，并且构成了种类繁多、多样的乳制品类别。本研究的目的是评估在卢布林市场上通过直接从生产商处购买的凝乳奶酪的物理化学、微生物学和感官质量。
研究材料是从三个生产商处分4次（每隔2周）购买的家庭自制凝乳奶酪。测定了奶酪中的物理化学参数（即总蛋白质和脂肪含量、活性酸度和可滴定酸度）。进行微生物分析以评估细菌总数（在牛奶琼脂上）、酵母和霉菌数量（在沙氏培养基上）以及大肠菌群数量（在麦康凯培养基上）。由一个五人小组进行总体感官评价，他们评估了样品的外观和颜色、质地、风味和香气。
奶酪在蛋白质和脂肪含量上表现出显著差异，但这些值在允许范围内。大多数评估的奶酪活性酸度和可滴定酸度水平正常；仅在供应商A的样品中检测到可滴定酸度显著较低且pH值较高。凝乳奶酪样品中的细菌总数很高（3.2×10菌落形成单位[cfu]×g奶酪）且差异很大（从3.6×10到8.6×10 cfu×g）。在供应商B和C的样品中观察到麦康凯培养基上革兰氏阴性菌菌落生长（分别为5.5×10和1.7×10 cfu×g），这是一种不良现象。在沙氏培养基上培养并鉴定为酵母样微生物的菌落数量范围从1.8×10（供应商A的产品）到4.9×10 cfu×g（供应商C的奶酪）。测试的凝乳奶酪感官评价得分较低。外观和颜色的平均得分最高（4.25 - 4.45分）。相反，风味和香气得分最低（3.17分）。供应商A生产的凝乳奶酪在总体评估以及各个参数单独评估中得分最高。
我们的结果表明在牛奶收集、加工以及这些乳制品分销过程中的卫生条件较差。总体而言，从直接销售购买产品可能与消费者健康不佳和食品质量相关的风险有关。
