EFFECT OF HIGH-PRESSURE HOMOGENIZATION AND THERMAL PRETREATMENT ON THE RHEOLOGICAL AND PHYSICAL ATTRIBUTES OF AUTUMN CRISP APPLE PUREE

Apple puree is one of the most popular fruit-based products processed from fresh apples. The physicochemical attributes of apple puree are mainly affected by the processing operation. High pressure homogenization (HPH) is an innovative non-thermal technology that can be applied to puree production to make smoother, drinkable foods, and was selected for the present study. Multiple pressures and passes of HPH treatment were utilized, and the effect of preheating prior to HPH was evaluated to comprehensively assess the effect on the final product. The present study aimed to evaluate the effect of HPH on the physicochemical properties of minimally processed, refrigerated, Autumn Crisp apple puree including particle size distribution, color change, microstructure, syneresis, apparent viscosity, and dynamic rheological properties. High pressure processing (HPP) was applied to preserve final samples for refrigerated shelf-life evaluation. The results were analyzed by one-way ANOVA and Tukey’s HSB test at a 95% confidence level. Thermal treatment prior to HPH increased viscosity and color changes over refrigerated storage time (15 weeks). In the final apple puree products, HPH process decreased the mean particle size from 285 _m to 12-98 _m depending on pressure and passes applied, resulting in significant changes on particle microstructure, lower viscosity and smoother consistency. The storage modulus (G’) and loss modulus (G’’) also declined in HPH puree samples, with G’ values an order of magnitude larger than G’’ values, indicating a weak gel character. The serum-holding capacity decreased as applied pressure increased, resulting in higher serum separation by centrifugation from 43% to 67%, suggesting that HPH negatively affected physical stability. Color changes were observed only at the highest applied HPH pressure of 207 MPa. The results from this study increase the understanding of how HPH affects the attributes of fruit purees, to facilitate the utilization of HPH technology in industrial fruit processing, with possible applications for production of drinkable purees.

Name thesis:degree_name

M.S., Food Science and Technology

Level thesis:degree_level

Master of Science

Discipline thesis:degree_discipline

Food Science and Technology

Grantor

Cornell University

Year dc:date.issued

2020

Author dc:creator

• Shi, Shengping

Committee member dc:contributor.committeemember

• Moraru, Carmen I.

Statement dc:rights

• Attribution-NonCommercial-NoDerivatives 4.0 International

Licence dc:rights.uri

• https://creativecommons.org/licenses/by-nc-nd/4.0/

Language dc:language.iso

en

DOI

https://doi.org/10.7298/q776-3004

Dc Identifier Other

ProQuest Submission ID: 11050
ProQuest Publication ID: 28089123

OAI identifier oai:identifier

oai:ecommons.cornell.edu:1813/103133