Emiliano Cocci

A novel fluorescence microscopy approach to estimate quality loss of stored fruit fillings as a result of browning

The aim of the present study was to estimate the quality deterioration of apple fillings during storage. Moreover, a potentiality of novel time-saving and non-invasive method based on fluorescence microscopy for prompt ascertainment of non-enzymatic browning initiation in fruit fillings was investigated. Apple filling samples were obtained by mixing different quantities of fruit and stabilizing agents (inulin, pectin and gellan gum), thermally processed and stored for 6-month. The preservation of antioxidant capacity (determined by DPPH method) in apple fillings was indirectly correlated with decrease in total polyphenols content that varied from 34±22 to 56±17% and concomitant accumulation of 5-hydroxymethylfurfural (HMF), ranging from 3.4±0.1 to 8±1mg/kg in comparison to initial apple puree values. The mean intensity of the fluorescence emission spectra of apple filling samples and initial apple puree was highly correlated (R(2)>0.95) with the HMF content, showing a good potentiality of fluorescence microscopy method to estimate non-enzymatic browning.

Response of Pink Lady® apples to post-harvest application of 1-methylcyclopropene as a function of applied dose, maturity at harvest, storage time and controlled atmosphere storage.

BACKGROUND 1-Methylcyclopropene (1-MCP) is an inhibitor of ethylene reception used in post-harvest treatments to delay fruit ripening. Several factors affect the efficacy of 1-MCP treatments. The effect of a post-harvest treatment with 1-MCP on the quality of Pink Lady® apples as a function of 1-MCP dose, storage time and maturity at harvest was investigated. 1-MCP treatment was further tested in combination with controlled atmosphere (CA) storage. RESULTS 1-MCP limited fruit respiration and softening during storage and was more effective on partially matured fruits and at prolonged storage times. The delaying of 1-MCP on the increase of ripening index was greater on matured fruits at prolonged storage times. The combination of 1-MCP and CA treatments positively affected quality indices of mature apples during 6 months of storage and 7 days of commercial life, with 1-MCP being more effective than CA. 1-MCP and CA showed positive combined effects on firmness and ripening index after 6 months of storage, and on firmness and CO₂ production after a further 7 days of commercial life. CONCLUSION By knowing fruit maturity at harvest and expected storage time it is possible to choose the most suitable 1-MCP dose to meet the market requirements by applying a simple polynomial model.

Modified atmosphere packaging of hen table eggs: Effects on functional properties of albumen

The aim of this study was to compare technological properties (gel hardness, foam drainage, and meringue crispness) of albumen of nonpacked table eggs (control) with those of eggs packed in high-barrier plastic pouches with 3 modified atmosphere packaging (MAP) conditions (air, 100% N(2), and 100% CO(2)) during 28 d of storage at 25°C. The values of gel hardness for the control sample showed an increasing trend, demonstrating the highest values throughout the experiment duration compared with the other samples. This behavior was probably attributable to the pH increase detected only for this sample during storage (from 8.82 ± 0.06 for fresh egg to 9.96 ± 0.06 at the end of the experiment). Air and N(2) samples showed constant and similar hardness values during storage. The hardness of coagulated albumen showed a strict correlation with raw albumen pH (r(2) = 0.929; P < 0.001). Other than reducing albumen pH during storage, MAP with CO(2) caused the formation of a soft and puffy coagulum with very low hardness, reaching the lowest value of 1.26 ± 0.38 N after 4 d of storage, that slowly increased to 2.11 ± 0.49 N at the end of the experiment. Foam stability decreased during storage for all samples, but CO(2) eggs showed a significantly (P < 0.05) higher foam stability than fresh eggs until 15 d, reaching values similar to those of the other samples only at the end of the storage time. Packing eggs in CO(2) promoted an improvement of meringue crispness. The application of this atmosphere could ameliorate the quality characteristics of albumen-based food products. Commercially, CO(2) MAP could provide an albumen-based ingredient tailored to maximize the characteristics needed in the final product (e.g., fresh shell eggs special for meringue preparation) that could give an added value to the product.