Premium
Effects of high‐power ultrasound on microflora, enzymes and some quality attributes of a strawberry drink
Author(s) -
Chen Liyi,
Bi Xiufang,
Cao Xiamin,
Liu Lei,
Che Zhenming
Publication year - 2018
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.9079
Subject(s) - food science , enzyme , ultrasound , quality (philosophy) , microbiology and biotechnology , chemistry , biology , biochemistry , medicine , physics , quantum mechanics , radiology
BACKGROUND The objective of the present work was to study the effect of high‐power ultrasound (HPU) on the microflora, enzymes and some quality attributes of a strawberry drink and to provide a theoretical basis for strawberry drink processing conducive to the development of more nutritious and healthier strawberry drinks. RESULTS Fresh strawberry drink was subjected to HPU treatment at 20 kHz (242, 605 and 968 W cm −2 ) for 2, 4, 6, 8 and 10 min in an ice bath. Results showed that polyphenol oxidase (PPO), pectin methyl esterase (PME) and β ‐glucosidase activities were decreased by 44.90, 89.11 and 84.71% respectively at 968 W cm −2 for 10 min. Lower L* , a* and b* values and higher browning degree (BD) were observed in HPU‐treated samples, resulting in a significant increase in Δ E value ( P < 0.05). HPU treatment caused loss of viscosity and turbidity, while total soluble solids (TSS) and pH of the strawberry drink were stable. Total phenol content and antioxidant capacity increased while anthocyanin content decreased compared with untreated samples. Total aerobic bacteria (TAB) and molds and yeasts (M&Y) were reduced by 2.07 and 1.13 log 10 cycles respectively at 968 W cm −2 for 10 min. CONCLUSIONS HPU can effectively achieve the effect of pasteurization and maintain the nutrients of strawberry drink. © 2018 Society of Chemical Industry