Effects of gamma irradiation on the sensory and metabolic profiles of two peach cultivars.

BACKGROUND: The suitability of commercial peaches for minimal processing (MP) is limited, mainly due to shortened shelf-life. Gamma irradiation has emerged in MP fruits as a promising technology. This study aimed to investigate the effects of gamma irradiation on the sensory and metabolic profiles of MP peaches from two cultivars - 'Forastero' (FT) and 'Ruby Prince' (RP) - and evaluate the relationship between both profiles. MP peaches were packaged and divided into two groups: one without additional treatment (K) and the other subjected to gamma irradiation (1.0 kGy, I- irradiation treatment), making a total of four samples (FTK, FTI, RPK and RPI). The sensory profile was carried out by an assessor panel. Metabolite analysis was accomplished by gas chromatography-mass spectrometry. RESULTS: Irradiation significantly affected color, homogeneity, peach aroma, total flavor intensity, peach flavor, sweetness and juiciness in FT, increasing their intensities. In the RP cultivar, irradiation increased brightness, total aroma intensity, peach aroma, and flavor and texture descriptors. Regarding metabolites, only malic acid and sucrose increased their concentrations in the irradiated samples. Partial least squares showed that sucrose was mainly correlated with sweet, total aroma intensity and peach flavors, and linked with FTI sample. Bitter along with peach aroma and total intensity flavor were associated with RPI sample. CONCLUSION: The applied dose accelerated the ripening process of the peach. The study highlights the importance of complementing sensory analysis with metabolomics tools to optimize fruit quality in minimally processed peaches. © 2023 Society of Chemical Industry.

Stress relaxation characteristics of low-fat chicken sausages made in Argentina.

Low-fat sausages were prepared with fresh chicken breast meat and formulated with different levels of added fat, whey protein concentrate, and hydrocolloids (xanthan and guar gums) to study the effect of composition on the stress relaxation behavior of the products. Stress relaxation experiments were conducted on precooked sausages at 25°C. Generalized Maxwell and empirical Peleg models were used to predict the stress relaxation behavior of the material. A model with seven maxwellian elements in parallel with a pure elastic element showed a very good agreement with experimental data. Results show that the proposed model satisfactorily fits the experimental data better than Peleg's model or Maxwell models with less elements. The relaxation time distribution functions were obtained. The characteristic relaxation time was shorter (2500s) for the formulations with no added fat which produced a less elastic product while the sausages with added fat showed longer characteristic relaxation time (5000s). The stress relaxation experiment differentiated the viscoelastic nature of different formulations due to reduction of fat content.