Glass Kathleen A, Johnson Eric A
Food Research Institute, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
J Food Prot. 2004 Aug;67(8):1687-93. doi: 10.4315/0362-028x-67.8.1687.
The effects of fat, type of natural cheese, and adjunct process cheese ingredients were evaluated to determine factors that contribute to the botulinal safety of reduced-fat (RF) process cheese products stored at 30 degrees C. In the first set of experiments, pasteurized process cheese products (PPCPs) were formulated using full-fat (FF) Cheddar, 30% RF Cheddar, or skim milk (SM) cheese as cheese-base types and were standardized to 59% moisture, pH 5.75, 2.8 or 3.2% total salts, and 15 to 19% fat. Subsequent trials evaluated the effect of fat levels and adjunct ingredients in PPCPs made with SM, RF, and FF cheese (final fat levels, less than 1, 13, and 24%, respectively). When fat levels of PPCPs were comparable (15.1, 19.1, and 16.2 for product manufactured with SC, RE and FF cheese, respectively), botulinal toxin production was delayed for up to 2 days in PPCPs formulated with SM compared with RF or FF cheese; however, the effect was not statistically significant. When fat levels were reduced to less than 1% in SM PPCPs, toxin production was delayed 2 weeks in products made with SM compared with RF or FF cheese manufactured with 13 or 24% fat, respectively. The antibotulinal effect of adjunct ingredients varied among the products manufactured with different fat levels. Sodium lactate significantly delayed toxin production (P < 0.05) for all fat levels tested, whereas beta-glucan fat replacer did not delay toxin production. An enzyme-modified cheese used as a flavor enhancer significantly delayed toxin production (P < 0.05) in SM (less than 1% fat) products but had little to no inhibitory effect in RF (13% fat) and FF (24% fat) cheese products. Similarly, monolaurin increased the time to detectable toxin in SM products but was ineffective in RF or FF cheese products. These results verify that RF PPCPs exhibit greater safety than FF products and that safety may be enhanced by using certain adjunct ingredients as antimicrobials.
评估了脂肪、天然奶酪类型和辅助加工奶酪成分的影响，以确定有助于在30摄氏度下储存的低脂（RF）加工奶酪产品肉毒杆菌安全性的因素。在第一组实验中，使用全脂（FF）切达干酪、30% RF切达干酪或脱脂牛奶（SM）奶酪作为奶酪基类型配制巴氏杀菌加工奶酪产品（PPCP），并将其水分标准化为59%、pH值为5.75、总盐含量为2.8%或3.2%，脂肪含量为15%至19%。随后的试验评估了脂肪水平和辅助成分对用SM、RF和FF奶酪制成的PPCP的影响（最终脂肪水平分别低于1%、13%和24%）。当PPCP的脂肪水平相当时（用SC、RE和FF奶酪生产的产品分别为15.1%、19.1%和16.2%），与用RF或FF奶酪配制的PPCP相比，用SM配制的PPCP中肉毒杆菌毒素产生延迟长达2天；然而，这种影响在统计学上并不显著。当SM PPCP中的脂肪水平降至低于1%时，与分别用13%或24%脂肪制成的RF或FF奶酪相比，用SM制成的产品中毒素产生延迟2周。辅助成分的抗肉毒杆菌作用在不同脂肪水平生产的产品中有所不同。乳酸钠显著延迟了所有测试脂肪水平下的毒素产生（P < 0.05），而β-葡聚糖脂肪替代品并未延迟毒素产生。用作风味增强剂的酶改性奶酪在SM（脂肪含量低于1%）产品中显著延迟了毒素产生（P < 0.05），但在RF（脂肪含量13%）和FF（脂肪含量24%）奶酪产品中几乎没有抑制作用。同样，月桂酸单甘油酯增加了SM产品中可检测到毒素的时间，但在RF或FF奶酪产品中无效。这些结果证实，RF PPCP比FF产品具有更高的安全性，并且使用某些辅助成分作为抗菌剂可能会提高安全性。
