The effect of pulsed light (PL) on numerous important quality characteristics of pineapple juice was studied and compared with untreated and thermally pasteurised samples. The laboratory scale PL batch system used was operated with each three different voltages (1.8, 2.1, and 2.4 kV) and numbers of pulses (47, 94, and 187). Treatments with 2.4 kV and either 94 or 187 pulses (757/1479 J·cm⁻²) resulted in a 5-log reduction in aerobic mesophiles and the yeast and mould counts. Peroxidase was more resistant to PL than polyphenol oxidase, whereas the bromelain activity was completely retained in all PL-treated juices. Colour and antioxidant capacity were minimally affected, while vitamin C, genuine pineapple furanones, and phenolic compounds declined. In contrast, thermal pasteurisation was more detrimental to colour, antioxidant capacity, and vitamin C content, but resulted in a superior inactivation of microorganisms and enzymes and retention of phenolic compounds. Principal component analysis (PCA) permitted the differentiation of fresh, thermally pasteurised, and all PL-treated juices. PCA on the basis of the individual juice constituents additionally arranged the latter juices according to the number of pulses and voltage levels applied, particularly promoted by the oxidation of ascorbic to dehydroascorbic acid. In conclusion, PL treatment represents a promising new alternative to conventional thermal preservation techniques, whereby the inactivation of deteriorative enzymes may be further optimised.

研究了脉冲光（PL）对菠萝汁众多重要质量特性的影响，并将其与未经处理和热巴氏灭菌的样品进行了比较。使用的实验室规模的PL批处理系统分别在三个不同的电压（1.8、2.1和2.4 kV）和脉冲数（47、94和187）下运行。使用2.4 kV和94或187脉冲（757/1479 J·cm ^-2）导致有氧嗜温菌和酵母菌和霉菌数量减少了5个对数。过氧化物酶比多酚氧化酶对PL的抵抗力更高，而菠萝蛋白酶活性在所有PL处理过的果汁中完全保留。颜色和抗氧化能力受到的影响最小，而维生素C，真正的菠萝呋喃酮和酚类化合物则下降。相比之下，热巴氏灭菌法对颜色，抗氧化能力和维生素C含量更有害，但导致微生物和酶的出色失活以及酚类化合物的保留。主成分分析（PCA）允许区分新鲜的，热巴氏灭菌的和所有PL处理的果汁。基于各个果汁成分的PCA根据所施加的脉冲数和电压水平，特别是通过抗坏血酸氧化为脱氢抗坏血酸的促进，进一步安排了后者的果汁。总之，PL处理代表了常规保温技术的一种有希望的新替代方法，从而可以进一步优化降解酶的失活。