Fruit Quality

Georgia Peaches in a market stand

Commercial peach growers in the Southeastern U.S. grow approximately 40-60 different peach varieties, with each variety having a harvest window of only one to three weeks of marketable fruit. Per capita consumption of peaches has declined from 2.4kg in 1995 to 1.3kg in 2015 and has been linked to the reduction of consumer peach acceptability. Dr. Chavez recognized the need to characterize the variation in quality attributes (appearance, aroma and flavor, and texture) in the varieties currently grown in Georgia. Dr. Chavez in collaboration with Mr. Lawton Pearson from Pearson Farms established this research project to understand the inherent variation of peach quality. This research was Ms. Catherine Belisle’s MS project. She participated in all project activities including fruit collection, transport, evaluation, consumer panels, and quality instrumental evaluation.

Dr. Chavez in collaboration with Dr. Adhikari in the Food Science Department decided to first standardize the sensory vocabulary used to characterize the fruit quality of peaches. This vocabulary consists of terms, definitions, and references that would allow any individual across the globe to describe, to compare, and to relate consumer perceptions for different peach varieties for appearance, firmness, flavor and aromas. This vocabulary, called a lexicon, was published in the Journal of Sensory Studies with the title of, “Development of a lexicon for flavor and texture of fresh peach cultivars”. Similarly, Dr. Chavez and Ms. Belisle implemented several instrumental quality tests such as SSC, TTA, firmness (as measured by puncture, compression, and Kramer test), flavor volatile profile (as measured using GC-MS), color (as measured by a colorimeter), and sugars and acids profile (as measured using HPLC) to characterize fruit quality variation in peaches. The partial results of the instrumental tests for firmness, SSC, TTA, and color for 30 varieties of peaches grown in Georgia across two seasons were published in HortTechnology in 2018 with the title, “A survey of peach cultivars quality grown in the Southeastern U.S.”.

Dr. Chavez and Dr. Adhikari finished establishing an additional year of data collection for consumer and descriptive panels in conjunction with instrumental analyses. The objective was to identify major characteristics that will contribute to consumer acceptability and that could be used in the future. This research yielded information of varieties with superior quality characteristics and identify breeding targets for future peach breeding and selection. This information is currently being prepared for publications. Other possible project deriving of this survey is to characterize the effect of different postharvest treatments in the quality attributes associated with consumer acceptability. Once superior varieties are identified, transcriptome analyses can be done to identify gene targets associated with these quality attributes which is a tool that can be used in breeding for peaches with increased quality.