Change in Quality of Mixed Juice of Fruits and Vegetables by Aseptic Treatment and Packing with Nitrogen Gas during Storage

제균처리와 질소가스포장에 따른 혼합과채주스의 저장 중 품질 변화

  • Kim, Su-Yeun (Department of Food and Microbial Technology, Seoul Women's University) ;
  • Yoon, Young-Bean (Department of Food and Microbial Technology, Seoul Women's University) ;
  • Choi, Eon-Ho (Department of Food and Microbial Technology, Seoul Women's University)
  • 김수연 (서울여자대학교 식품 미생물공학과) ;
  • 윤영빈 (서울여자대학교 식품 미생물공학과) ;
  • 최언호 (서울여자대학교 식품 미생물공학과)
  • Published : 2000.12.30

Abstract

The extracts from tomatoes, apples, carrots, mallows, watercreses+pine needles, Angelica keiskei Koiz, jujubes and lemons were selected and mixed at the ratio of 3 : 3 : 3 : 1/2 : 1/2 : 1/2 : 1/2 : 1/5 on the basis of sensory evaluation. The mixed extracts were divided into three lots and treated as follows. The first lot was heated for 15 sec at $96^{\circ}C$ without centrifugation and filtration, the second filtered through a ultramembrane filter. For the third one, the ultrafiltrate combined with autoclaved retentates on the membrane filter and the previous centrifugal precipitation. The mixed juices were stored in the glass bottles with atmosphere or in film package with nitrogen gas. And then they were stored at $4^{\circ}$ and $20^{\circ}C$. During storage the treated juices showed $pH\;4.07{\sim}4.10$, titratable acidity $66.35{\sim}84.08$, soluble solid $7{\sim}9^{\circ}Brix$, reducing sugar $5.42{\sim}6.97%$, glucose $1.96{\sim}2.30%$ and fructose $3.46{\sim}4.14%$. The ultrafiltered juices showed yellow color, different from orange color of other treatment lots. Peroxidase activity and microbial population were inhibited by thermal treatment and ultrafiltration. The browning effects of the mixed juice of fruits and vegetables during storage were caused by ascorbic acid oxidation and non-enzymatic browning reaction, which could be reduced by change and packing with nitrogen gas instead of atmosphere inside bottles.

Keywords

mixed juice;preservation;nitrogen gas;aseptic treatment;ultrafiltration