微酸性次氯酸水对鲜切莴笋的保鲜作用效果

Effect of Slightly Acidic Hypochlorous Acid Water on the Preservation of Fresh-cut Lettuce

鲜切果蔬的保质期短,容易受到食源性病原菌的污染。该研究以鲜切莴笋为试材,基于单因素和正交试验,研究微酸性次氯酸水(Slightly Acidic Hypochlorous Water,SAHW)对鲜切莴笋的保鲜作用及对贮藏品质的影响。采用SAHW有效氯浓度、处理温度、处理时间及处理方式4个因素,在基于单因素试验的基础上,进行四因素三水平正交试验,并验证最佳处理方式对鲜切莴笋在贮藏期间的感官品质、菌落总数、抗坏血酸(Vitamin C,Vc)含量和丙二醛(Malondialdehyde,MDA)含量的影响。结果表明,SAHW对鲜切莴笋具有较好的保鲜作用,各因素影响为处理方式>处理时间>SAHW有效氯浓度>处理温度。最佳保鲜处理方式为在15℃下有效氯质量浓度为50 mg/L的SAHW震荡浸泡5 min,此处理组合下感官评分为5.22,a^(*)值为-2.73,菌落总数为3.79 lg CFU/mL,并在贮藏期间有效保持了鲜切莴笋的感官品质,在贮藏第25天时,菌落总数仅为0.72 lg CFU/mL,抑制了菌落总数的增长、Vc为14.5 mg/100 g和MDA为0.26 nmol/g,显著降低了Vc的损失和MDA的积累,延长了鲜切莴笋保鲜期,为SAHW用于鲜切莴笋保鲜剂提供科学依据。

Fresh-cut fruits and vegetables have a short shelf life and are prone to contamination by foodborne pathogens.In this study,fresh-cut lettuce was used as the test material,and based on single factor and orthogonal experiments,the preservation effect of slightly acidic hypochlorous water(SAHW)on fresh-cut lettuce and its influence on storage quality were studied.Using four factors SAHW available chlorine concentration,treatment temperature,treatment time and treatment method,on the basis of single factor experiments,a four-factor three-level orthogonal test was conducted to verify the effect of the best treatment on the sensory quality,total bacterial count,ascorbic acid(Vc)content and Malondialdehyde(MDA)content of fresh-cut lettuce during storage.The results showed that SAHW had a good preservation effect on fresh-cut lettuce,and the influencing factors were the treatment method>treatment time>effective chlorine concentration of SAHW>treatment temperature.The best preservation treatment was shaking and soaking in the SAHW with an effective chlorine concentration of 50 mg/L for 5 min at 15℃.Under this treatment,the sensory score was 5.22,the a^(*)value was-2.73,and the total bacterial count was 3.79 lg CFU/mL.This treatment maintained effectively the sensory quality of fresh-cut lettuce during storage.On the 25th day of storage,the total bacterial count was only 0.72 lg CFU/mL(indicating the inhibition of the growth of bacterial colonies),Vc was 14.5 mg/100 g,and the MDA was 0.26 nmol/g,indicating the reduction of Vc loss and MDA accumulation significantly and extension of the shelf life of fresh-cut lettuce.The results provide a scientific basis for SAHW to be used as a preservative agent for fresh-cut lettuce.