Jiménez-Maroto L A, Govindasamy-Lucey S, Jaeggi J J, Johnson M E, Lucey J A
Department of Food Science, University of Wisconsin-Madison, Madison, WI 53706.
Center for Dairy Research, University of Wisconsin-Madison, Madison, WI 53706.
J Dairy Sci. 2025 Apr 28. doi: 10.3168/jds.2025-26527.
Direct-salted, block Gouda has recently become a popular cheese that is made in the United States, mostly for export purposes. The dairy industry uses 2 types of manufacturing options for this cheese; stirred curd (SC) and milled curd (MC), and we wanted to explore if there were any differences in the properties of cheese made with these 2 different methods. We also investigated 2 options to help extend the performance shelf life and functionality of this direct-salted Gouda cheese: high-pressure processing (HPP) and the use of different storage temperatures. Batches (n = 4) of direct-salted Gouda cheese were produced using a reduced proteolytic coagulant (camel chymosin to help extend the shelf life) by both SC and MC Gouda cheese approaches. After 1 mo of ripening, cheeses were divided into 2 pressure groups: control (non-HPP) and HPP (600 MPa for 3 min), then stored at 3 different storage temperatures (-18, 0, or 4°C). Analyses were performed during storage up to 365 d. The pH of samples stored at 4°C and non-HPP treated increased significantly during storage. There was little change in the pH values for all the HPP-treated samples or non-HPP samples stored at 0°C or at -18°C. Starter and nonstarter bacteria counts were reduced by ∼3 and 5 log cfu/mL, respectively, by HPP. In the HPP-treated samples stored at 4°C, bacterial numbers slowly increased during the 365-d storage period. Proteolysis (pH 4.6 soluble N) was negatively affected by the use of lower storage temperature and HPP treatment. Dynamic small-amplitude oscillatory rheology indicated that cheese meltability (maximum loss tangent) was increased by HPP treatment, likely due to the small, immediate reduction in the insoluble calcium levels in cheese caused by HPP. Hardness decreased during cheese storage at -18°C, possibly due to some disruption in the body of the cheese (e.g., more brittleness) because of freezing/thawing. The length of shreds prepared from Gouda cheese greatly decreased during storage at 4°C and in frozen samples that were non-HPP treated. Shred length was mostly retained during the 365-d period in samples stored at 0°C and HPP treated. The MC cheese had a longer shred functionality shelf life than the SC cheese. Frozen Gouda cheese exhibited some loss of functionality during the long storage period. The combination of storage at 0°C and HPP treatment helped to retain high performance properties during the 365-d shelf life and could be another attractive option for extending the performance shelf life of direct-salted Gouda cheese.
直接盐渍块状豪达奶酪最近在美国成为一种受欢迎的奶酪，主要用于出口。乳制品行业在生产这种奶酪时有两种制造方式；搅拌凝乳（SC）和磨碎凝乳（MC），我们想探究用这两种不同方法制作的奶酪在特性上是否存在差异。我们还研究了两种有助于延长这种直接盐渍豪达奶酪的性能保质期和功能的方法：高压处理（HPP）以及使用不同的储存温度。采用减少蛋白水解作用的凝乳酶（骆驼凝乳酶以帮助延长保质期），通过SC和MC豪达奶酪制作方法生产了多批次（n = 4）直接盐渍豪达奶酪。成熟1个月后，将奶酪分为两个压力组：对照组（非HPP）和HPP组（600兆帕，处理3分钟），然后在3个不同储存温度（-18℃、0℃或4℃）下储存。在长达365天的储存期内进行分析。储存在4℃且未经HPP处理的样品的pH值在储存期间显著升高。所有经HPP处理的样品或储存在0℃或-18℃的非HPP样品的pH值变化不大。HPP处理分别使发酵剂和非发酵剂细菌数量减少约3和5个对数菌落形成单位/毫升。在储存在4℃的经HPP处理的样品中，细菌数量在365天的储存期内缓慢增加。较低的储存温度和HPP处理对蛋白水解作用（pH 4.6可溶性氮）有负面影响。动态小振幅振荡流变学表明，HPP处理提高了奶酪的可熔性（最大损耗角正切），这可能是由于HPP导致奶酪中不溶性钙水平立即小幅降低。在-18℃储存期间奶酪硬度降低，可能是由于冷冻/解冻导致奶酪质地出现一些破坏（例如更脆）。从豪达奶酪制备的切丝长度在储存在4℃的样品以及未经HPP处理的冷冻样品中在储存期间大幅缩短。在储存在0℃且经HPP处理的样品中，切丝长度在365天期间大多得以保留。MC奶酪的切丝功能保质期比SC奶酪长。冷冻豪达奶酪在长期储存期间表现出一些功能损失。在0℃储存和HPP处理相结合有助于在365天保质期内保持高性能特性，并且可能是延长直接盐渍豪达奶酪性能保质期的另一个有吸引力的选择。
