[6-1130-P] Postharvest/Food Technology and Process Engineering (6th)

[6-1130-P-30] High pressure processing of ‘Nanglae’ pineapple juice: Quality preservation and shelf life extension

Nuntawan Chuensombat¹, Natthakan Rungraeng¹, Sutthiwal Setha^1,2, *Phunsiri Suthiluk^1,2 (1. School of Agro-Industry, Mae Fah luang University, Chiang Rai, THAILAND(Thailand), 2. Research Group of Postharvest Technology, School of Agro-Industry, Mae Fah Luang University, Chaing Rai, THAILAND(Thailand))

Keywords:Bioactive compounds, Fruit juice, High hydrostatic pressure

Quality changes and shelf life of high pressure processed (HPP) ‘Nanglae’ pineapple juice were compared to fresh and conventional pasteurized (CP) juices during storage at 5+1°C. A hundred percentage of fresh ‘Nanglae’ pineapple juice was pressure processed at 400 or 600 MPa for 5, 10 or 15 min and stored at 5+1°C for up to 60 days. The pasteurized condition of 80°C for 10 min was used as a control. Changes in pH, total soluble solid (TSS), titratable acidity (TA), color (L* and b*), bioactive compounds (Ascorbic acid, total carotenoid and total phenolic compounds), antioxidant activities (DPPH and FRAP assay) and microbiological quality (Aerobic plate count (APC) and yeast and mold count (YM)) were determined every 5 days until the end of storage time. It was found that pH, TSS, TA and color was no significant different (P>0.05) among HPP juice. After treatment, higher ascorbic acid and total carotenoid content was observed in HPP pineapple juice in a range of 4.72-6.09 and 0.38- 0.41 mg/100 ml, respectively while in CP juice was 2.36+0.59 and 0.31+0.01 mg/100 ml. Moreover, total phenolic compounds content in sample treated with 400 and 600 MPa HPP for 5 min was significantly higher than CP sample (45.45+0.49, 47.82+0.35 and 41.00+1.68 mg GAE/100 ml, respectively). The highest FRAP value was also found in sample treated with HPP at 400 and 600 MPa for 5 min as 709.00+7.37 and 692.50+9.01 µmol FeSO4/100 ml while there was no significant different (P>0.05) in DPPH value of all samples. In addition, HPP at 600 MPa for 5 min decreases APC and YM to be less than 1.48+0.00 and 1.18+0.00 log CFU/ml which was similar to CP treatment. Shelf life of HPP ‘Nanglae’ pineapple juice was estimated about 60 days at 5+1°C limited by juice precipitation. Therefore HPP could be an alternative to pasteurization for juice production which preserve nutritional value and organoleptic properties as well as maintain quality and safety of product.