Effect of hyperbaric, controlled atmosphere, and UV treatments on peach volatiles

Abstract

The effect of hyperbaric (HP) and controlled atmosphere (CA) storage and prestorage treatment with ultra violet (UV) radiation on the volatile chemistry of peach [ Prunus persica (L.) Batsch] fruit was assessed. Peach volatiles were analyzed using a dynamic headspace system with Tenax trap, automated short path thermal desorption, and GC–MS. The composition of volatile compounds emanating from the fruit varied quantitatively and qualitatively with storage (4 weeks). A total of 65 volatiles were identified, 21 prior to storage and 59 after 4 weeks storage. Six of the prestorage volatiles were not found after storage. The concentration of total volatiles and esters, the highest relative proportion of primary classes increased 32.5- and 36.5-fold, respectively, during storage. Ethyl butanoate, ethyl hexanoate, and ethyl heptanoate contributed to peach aroma due to their low odor thresholds and high concentrations. Using a factorial design (2 × 2 × 2), the main effects [storage pressure (P), storage gas atmosphere (A), and UV pretreatment] and interactions (P × A, P × UV, A × UV, and P × A × UV) were determined. P contributed most to the concentration of total volatile compounds followed by A; HP and HP + CA with or without UV significantly reduced the concentration of total volatiles and esters. Prestorage UV irradiation treatment did not affect the emission of volatile compounds. Principal component analysis (PCA) using 59 volatile compounds emanating from stored fruit indicated a significant effect of P and A on the emission of volatiles that were divided into four treatment groups accounting for 67.5% of the total variance, i.e., AP + Air, AP + CA, HP + Air, and HP + CA. The PCA distribution indicated which compounds contributed most to differences in volatile pattern among treatments: ethyl ( Z)-4-octenoate, ethyl heptanoate, ethyl octanoate, and decanal (AP + Air); 3-methylbutyl acetate, ethyl butanoate, ethyl hexanoate, and 2-methylbutanoate (HP + CA); nonanal and hexanal (AP + CA); and hexyl acetate (HP + Air).