REFRIGERATED STORAGE OF HIGH HYDROSTATIC PRESSURE (HHP) TREATED PITAYA (Stenocereus pruinosus) JUICE

This work focuses on HHP and refrigerated storage effects on the quality and acceptability of pitaya juice (pH 5.2, 10 degrees Bx, 9.5% solids) stored under refrigeration. Pitaya is a spheroid fruit from native Mexican cactus, with a juicy and sweet pulp. After 550 and 600MPa treatments for 16 and 12 miff respectively, pitaya juice was stored 60 d at 4 +/- 1 degrees C. No aerobic mesophiles were found immediately after HHP treatments, and during storage, population remained below 2 log(10) HHP mL(-1). In HHP treated juice, yeast and molds were undetectable and remained so during storage. After HHP treatments and during storage, no changes were observed in total soluble solids (9.8 10.0 Bx degrees j, luminosity (4.3 4.4%), and chroma (I 8.9-20.7). Depending on treatment condition, TRIP lowered residual PME activity by 59-63%. A further reduction reaching 25% was observed during storage. Acidity, phenolic compounds, betalains concentrations, and antioxidant activity were not affected by IMP hut a 43, 10, 14, and 5% decrease, respectively, was observed after 60 d of storage. Finally, sensorial acceptability was not affected by HHP but increased during storage reflecting an increased sweetness perception associated with lower acidity values. This study confirmed HHP as a viable alternative to commercialize pitaya juice with a refrigerated distribution shelf life exceeding 60 U.