Microorganisms and Some Quality of Red Grapefruit Juice Affected by High Pressure Processing and High Temperature Short Time

Abstract

The aim of this study was to evaluate the effects of high pressure processing (HPP; 550 MPa/10 min) and high temperature short time (HTST; 110°C/8.6 s) on microorganism, ascorbic acid, total phenols, antioxidant capacity, color, enzyme activity, and rheological behavior in red grapefruit juice during 30 days of storage at 4°C. After HPP, the total plate count (TPC) and yeast and molds (Y & M) in red grapefruit juice were significantly decreased by 4.83 and 4.15 log cycles and showed to be microbiologically safe during storage. The activity of pectin methylesterase (PME) and peroxidase (POD) was only inactivated by 22.5 % and increased by 10.4 % by HPP, but completely inactivated by HTST. For all the other quality properties (such as total phenols, ascorbic acid, antioxidant capacity, color) except cloud stability studied in this article, their retention was significantly better in the HPP-treated samples than in the HTST-treated samples during storage, which were closer to natural grapefruit juice. A longer shelf life was observed in HPP-treated grapefruit juice compared to HTST-treated ones.

Identification of Different Pink Pomelo Varieties by Gas Chromatography-mass Spectrometry and Olfactometry Coupled to Chemometrics

“…As shown in Table 2, there is a significant difference of pH, TA, TSS and Brix acid ratio among these six cultivars (P<0.05). As studied in our previous research [23], these phychemical properties has given the similar data. The significant difference of the color indexes and total phenols were also observed in all six cultivars.…”

Nonthermal Technologies for Fruit and Vegetable Juices and Beverages: Overview and Advances

“…Overall, the inactivation of spoilage enzymes in juices often leads to difficulties as the sensitivities of enzymes are unpredictable and rely on the kind of product (Chakraborty and others ). In addition, there are some evidences on a possible enhancement of enzyme activity (Chakraborty and others ), as reported by Gao and others () for POD in pummelo juice, and Huang and others () for polyphenol oxidase (PPO) and POD in apricot nectar. However, under proper conditions, HHP treatment can result in the inactivation of enzymes, as recently confirmed by Juarez‐Enriquez and others () for PME in apple juice, and Rao and others () for PPO and PME in peach juice, respectively.…”

Thermal Treatments for Fruit and Vegetable Juices and Beverages: A Literature Overview

“…The effects of HTST treatment on different enzymes were also studied; it could: (1) reduce PME (95.3%) and PPO (90.9%) in apple juice (Aguilar‐Rosas and others ); and (2) ensure the complete inactivation of PPO, POD, and PME in apricot nectar (Huang and others ), and PME and POD in pummelo juice (Gao and others ), respectively.…”