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Currently, in the case of kiwifruits, those fruit with a weight lower than 65 g are considered waste. The production of dried snacks with high nutritional functionality could be a valid alternative to use the kiwifruit waste, with positive economic impact on the entire production chain. Therefore, the aim of this work was to evaluate the effect of pulsed electric field – PEF (200 V cm-1) and/or osmotic dehydration – OD (trehalose at 40%) pre-drying treatments on drying kinetics at 50, 60, and 70°C, and on colour and nutritional properties (vitamin C and antioxidant compounds) of ‘Jintao’ (yellow-fleshed) kiwifruit snacks. At every temperature, the PEF treated snacks showed the highest drying rate. Moreover, PEF treatment appeared to be a valid innovative alternative for the production of fruit snacks with high nutritional quality. A better retention of vitamin C and antioxidant compounds was obtained in dried yellow kiwifruit subjected to PEF treatment.

Aromatized foods have undergone great development in recent decades due to the significant increase in industrially produced food, which is often subjected to aroma loss during processing and storage. Although thermal processing technologies contribute to food safety, they also accelerate several chemical reactions (e.g., lipid oxidation, Maillard reaction, caramelization), which influence the food sensory profile in different ways depending on the food composition and structure. In some cases, aromatization is in fact required to counterbalance such thermal-induced changes and/or to replace some natural flavor ingredients, which are not always available and/or are too expensive. Consequently, the food industry has been facing increasing pressure to develop and improve processing technologies and preservation techniques with minimal impact on the fresh taste, texture, and nutritional value of food products. Moreover, optimal formulation and processing strategies of food aroma incorporation systems are needed to warrant their successful inclusion and protection, thus avoiding their degradation and formation of off-flavor and/or off-odor in the final products. Recently, a series of emerging processing technologies (e.g., nonthermal technologies, nanotechnology) have been explored as an alternative to conventional technologies, in order to obtain safe products with sensory and nutritional attributes similar to those of fresh products. These techniques aim to improve their sustainability and to reduce their environmental impact, without disregarding the process performance parameters and the quality and safety of food aroma compounds. This chapter provides an overview of the main natural and technology-derived food aroma compounds, with a critical focus on the novel extraction and delivery strategies, as well as on the effects of emerging food processing technologies on food aroma.

Attention is drawn to the feasibility of using high sensitivity isothermal heat conduction calorimetry to study metabolic responses of differently processed and stored fresh-cut fruit. The heat production of endogenous (tissue metabolism during 12 h of analysis at 10 °C for kiwifruit and strawberry) and exogenous (microbial growth during 18 d of analysis at 10 °C for cantaloupe) biological processes was investigated. Osmotic dehydration of fresh kiwifruit in sucrose solution (61.5 g/L) at different treatment times (30, 60 and 180 min), resulted in metabolic heat production decrease, confirming the progressive cell death induced by osmotic dehydration. Analysis on strawberry slices under two atmospheric conditions (air and innovative modified atmosphere) seemed to confirm the inhibitory effect of N2O on metabolic activity. Cantaloupe samples immersed in three different syrups (SS: sucrose syrup (20 °Brix); SS1: SS + 0.5 g/L ascorbic acid + 0.5 g/L citric acid; SS2: SS1 + 0.1 g/L potassium sorbate) showed a stability increase when additives with antimicrobial properties were included. Our findings confirm that isothermal calorimetry provides a versatile and high sensitive tool for conducting fundamental metabolic studies on the effect of different processing operations on the quality and shelf life of fresh-cut fruit and vegetables. Fil: Rocculi, Pietro. Università di Bologna; Italia Fil: Panarese, Valentina. Università di Bologna; Italia Fil: Tylewicz, Urszula. Università di Bologna; Italia Fil: Santagapita, Patricio Roman. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina Fil: Cocci, Emiliano. Università di Bologna; Italia Fil: Gómez Galindo, Federico. Lund University; Suecia Fil: Romani, Santina. Università di Bologna; Italia Fil: Dalla Rosa, Marco. Università di Bologna; Italia

The objective of the present study was to evaluate cellular compartment modifications of kiwifruit (Actinidia deliciosa) outer pericarp tissue caused by osmotic treatment in a 61.5 % sucrose solution, through the quantification of transverse relaxation time (T 2) and water self-diffusion coefficient (D w) obtained by low field nuclear magnetic resonance means. Raw material ripening stage was taken into account as an osmotic dehydration (OD) process variable by analyzing two different kiwifruit groups, low (LB) and high (HB) °Brix. Three T 2 values were obtained of about 20, 310, and 1,250 ms, which could be ascribed to the proton populations, located in the cell walls, in the cytoplasm/extracellular space, and in the vacuoles, respectively. According to T 2 intensity values, vacuole protons represented between 47 and 60 % of the total kiwifruit protons, for LB and HB kiwifruits, respectively. The leakage of water leading to vacuole shrinkage seemed to cause concentration of solutes, retained by the tonoplast, making the vacuole T 2 value decrease along the OD. As expected, the D w values of raw kiwifruits were lower than the value of the free pure water. The water mobility (and hence D w), depending on the kiwifruit distinctive cellular structures and solutes, decreased even more during OD due to water loss and sugar gain phenomena. D w represents an average value of the diffusion coefficient of the whole kiwifruit tissue protons. In order to obtain D w values specific for each cellular compartment, a multiple component model fitting was also used. According to these results, the vacuole water self-diffusion coefficient (D w,v) was much higher than D w.