这里首次提出了一种新的非热食品巴氏杀菌方法,建议通过高压灭活(HI)称为低压长时间(LPLT)巴氏灭菌或中等压力巴氏灭菌(MPP)。为了测试这种对原料奶的新型巴氏杀菌工艺,在三种不同的压力水平(150、200和250MPa)下进行HI的MPP,超过24小时,在自然可变的不受控制的室温(≈20°C)下,并与在600MPa下进行高压处理(HPP)(一个循环90s,第二个循环120s),然后在冷藏下储存21天。根据获得的结果,MPP在250MPa下超过24小时会导致总好氧中温微生物(TAM)更高的微生物失活,乳酸菌(LAB)和肠杆菌科(ENT)(至少为2.2、1.7和1.3logCFU/mL,分别)比HPP(1.1、1.0和1.2logCFU/mL,对于相同的微生物)。此外,MPP显示接种的微生物明显减少到检测极限以下,对于所有压力,仅16小时内,无害李斯特菌的降低幅度至少为5.7、5.4和5.5,Senftenberg沙门氏菌,和大肠杆菌,分别。此外,在冷藏保存期间,MPP样品(200MPa和250MPa),与HPP相比,保持较低的TAM/LAB/ENT,对于HI的MPP,计数低于定量/检测限至少21天。MPP(200MPa和250MPa)也导致计数低于接种的微生物的检测极限,在冷藏下至少21天。HI的MPP结果非常有希望作为一种新的非热食品巴氏杀菌,由于实现了超过5个对数的营养细菌减少,在冷藏下计数保持低于定量/检测限至少21天。
A new nonthermal food pasteurization approach is here presented for the first time, proposed to be called low-pressure long-time (LPLT) pasteurization or moderate pressure pasteurization (MPP) by hyperbaric inactivation (HI). To test this novel pasteurization process on raw milk, MPP by HI was carried out at three different pressure levels (150, 200 and 250 MPa), over 24 h, at naturally variable uncontrolled room temperature (≈20 °C) and compared with high pressure processing (HPP) at 600 MPa (one cycle for 90 s and a second cycle of 120 s) followed by storage under
refrigeration for 21 days. Based on the results obtained, MPP at 250 MPa over 24 h caused higher microbial inactivation on total aerobic mesophiles (TAM), lactic acid bacteria (LAB) and Enterobacteriaceae (ENT) (of at least 2.2, 1.7 and 1.3 log CFU/mL, respectively) than HPP (1.1, 1.0 and 1.2 log CFU/mL, for the same microorganisms). Moreover, MPP showed a clear reduction of inoculated microorganisms to below the detection limit, in only 16 h for all pressures with reductions of at least 5.7, 5.4 and 5.5 for Listeria innocua, Salmonella senftenberg, and Escherichia coli, respectively. Additionally, during preservation under
refrigeration, MPP samples (200 MPa and 250 MPa), maintained lower TAM/LAB/ENT compared to HPP, being the counts below the quantification/detection limit for at least 21 days for MPP by HI. MPP (200 MPa and 250 MPa) resulted also in counts below the detection limit for the inoculated microorganisms up to at least 21 days under
refrigeration. The results of MPP by HI are very promising as a new nonthermal food pasteurization, since over 5 log reduction of vegetative bacteria were achieved, with counts maintained below the quantification/detection limit for at least 21 days under
refrigeration.