Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Departamento de Tecnología de Alimentos, Carretera de La Coruña km 7, 28040 Madrid, Spain.
Instituto Tecnológico Agrario de Castilla y León (ITACyL), Estación Tecnológica de la Leche, Carretera de Autilla s/n, 34071 Palencia, Spain.
Food Res Int. 2017 Oct;100(Pt 1):595-602. doi: 10.1016/j.foodres.2017.07.043. Epub 2017 Jul 26.
High pressure (HP) offers potential industrial applications in cheese preservation, but it is essential to provide knowledge concerning their effects on the ripening process and sensory characteristics. In this study, we investigated the effect of different HP treatments (200-500MPa at 14°C for 10min on day 7) on proteolysis, texture, colour, volatile compounds and sensory characteristics of semi-hard raw ewe milk cheese. HP treatments did not affect pH or dry matter values of 60-day-old cheeses. Treatments at pressure levels up to 400MPa led to significant (P<0.01) increases in the total free amino acids (FAA) content at 60days, compared to control cheese, although the cell-free aminopeptidase activity was lower. HP retarded the formation of some volatile compounds in cheeses, the number of compounds affected by HP being higher as the pressure level increased. Cheeses pressurized at 300-500MPa had lower levels of 2-butanone, 2-butanol, 2-propen-1-ol, 1-butanol and acetic acid than control cheese, cheeses pressurized at 400-500MPa lower levels of 1-propanol, 2-pentanol, and butyric and hexanoic acids, and cheeses pressurized at 500MPa lower levels of ethanol, 3-methyl-1-butanol and 3-methyl-2-buten-1-ol. All HP-treated cheeses showed higher fracturability values, and higher Hue angle and lower a* values than control cheese. Despite the differences detected by instrumental analyses between HP-cheeses and control cheese, few significant differences were found between the sensory characteristics of HP-cheeses and control cheese. Only the pressurization of cheese at 500MPa affected significantly (P<0.01) some of the sensory characteristics, with a negative effect on taste intensity but a positive effect on aroma quality. In summary, HP treatments at 200 and 300MPa showed the mildest effects on the characteristics of semi-hard raw ewe milk cheese. HP treatment of this cheese variety at 300, 400 and 500MPa prevented late blowing defect caused by Clostridium tyrobutyricum (Ávila et al., 2016, Food Microbiol. 60, 165-173). Thus, it may be concluded that HP treatment at 300MPa is the most adequate procedure, able to prevent late blowing with minimum changes in cheese characteristics.
高压（HP）在奶酪保鲜方面具有潜在的工业应用价值，但必须提供有关其对成熟过程和感官特性影响的知识。在这项研究中，我们研究了不同 HP 处理（200-500MPa 在 14°C 下处理 10min，第 7 天）对半硬生羊奶干酪的水解度、质地、色泽、挥发性化合物和感官特性的影响。HP 处理不会影响 60 天奶酪的 pH 值或干物质值。与对照奶酪相比，压力水平高达 400MPa 的处理会导致总游离氨基酸（FAA）含量在 60 天内显著增加（P<0.01），尽管无细胞氨肽酶活性较低。HP 会延迟奶酪中一些挥发性化合物的形成，受 HP 影响的化合物数量随着压力水平的增加而增加。在 300-500MPa 下加压的奶酪中，2-丁酮、2-丁醇、2-丙烯-1-醇、1-丁醇和乙酸的含量低于对照奶酪，在 400-500MPa 下加压的奶酪中 1-丙醇、2-戊醇和丁酸、己酸的含量较低，在 500MPa 下加压的奶酪中乙醇、3-甲基-1-丁醇和 3-甲基-2-丁烯-1-醇的含量较低。与对照奶酪相比，所有 HP 处理的奶酪都表现出更高的易碎性值，Hue 角更高，a* 值更低。尽管通过仪器分析在 HP 奶酪和对照奶酪之间检测到差异，但 HP 奶酪和对照奶酪的感官特性之间很少有显著差异。只有在 500MPa 下加压奶酪才会对某些感官特性产生显著影响（P<0.01），对味道强度有负面影响，但对香气质量有积极影响。总之，在 200 和 300MPa 下进行 HP 处理对半硬生羊奶干酪的特性产生的影响最温和。在 300、400 和 500MPa 下对这种奶酪品种进行 HP 处理可以防止酪丁酸梭菌（Ávila 等人，2016，食品微生物学。60,165-173）引起的后期吹胀缺陷。因此，可以得出结论，在 300MPa 下进行 HP 处理是最适当的程序，能够在奶酪特性最小变化的情况下防止后期吹胀。
