RESUMO
This study aimed to explore the applicability of electronic-nose (E-nose) as a rapid method in discriminating samples of sweet cherry cv "Ferrovia" stored in high-CO2 (16% O2 + 20% CO2 + 64% N2) or air (control) up to 21 days. Projection to Latent Structures (PLS) methods applied to E-nose data showed that fresh fruit and the packaged or unpackaged samples can be distinguished, according to both the storage condition and the storage days. Moreover, a correlation analysis between E-nose sensors and 45 volatile compounds were overall, obtained from all the investigated sweet cherry samples by Headspace Solid-Phase Microextraction (HS SPME) coupled to Gas Chromatography-Mass Spectrometry (GC-MS). These methods allowed to associate samples with a specific flavour profile to one or more E-nose sensors. Finally, quality attributes (visual quality, colour, firmness, antioxidant activity, total phenols, and sugar content) were assessed during storage. Among these, visual quality and berry deformation resulted affected by storage conditions, showing that high-CO2 treatment better preserved the fruit quality than control.
RESUMO
This study aimed to develop a low-calorie apricot nectar by replacing sucrose with different amount of Stevia rebaudiana bertoni (Rebaudioside A, 98%). Stevia has become very popular as sweetener for the production of low-calorie products but its addition could be a challenge for industry, since it could modify sensory features of the product and consumers' acceptance. To this end, apricot nectars without sugar, with sucrose 10%, and with different amounts of stevia were produced and evaluated for microbiological quality using the pour-plate technique, and physicochemical (pH, TTA, and a w) and nutritional (moisture, fat, protein, carbohydrates, and ash) characteristics. Furthermore, a sensory analysis of the samples was performed by a panel of trained judges using quantitative descriptive analysis. The effect of stevia addiction on the consumers' acceptance was investigated by 102 consumers of fruit juices that evaluated the overall acceptability of the samples using a structured 9-point hedonic scale. Levels of microbial groups in nectars were under the detection limit confirming a good hygienic practice within the production. Nectars produced with stevia resulted in significant reduction in caloric value from 86 kcal (nectar with 10% sucrose) to 49 kcal (nectars with stevia), without altering its typicality. Different sensory profiles among samples were pointed out; all the products are liked, but with a different level of pleasantness. The study highlighted that the apricot nectars with 0.07% stevia are characterized for sweet and liquorice aroma notes and received the same level of consumer acceptability of nectars produced with 10% sucrose.
RESUMO
The volatile profile of two hybrids of "Radicchio di Chioggia", Corelli and Botticelli, stored in air or passive modified atmosphere (MAP) during 12 days of cold storage, was monitored by solid phase micro-extraction (SPME) GC-MS. Botticelli samples were also subjected to sensory analysis. Totally, 61 volatile organic compounds (VOCs) were identified in the headspace of radicchio samples. Principal component analysis (PCA) showed that fresh product possessed a metabolic content similar to that of the MAP samples after 5 and 8 days of storage. Projection to latent structures by partial least squares (PLS) regression analysis showed the volatiles content of the samples varied depending only on the packaging conditions. Specifically, 12 metabolites describing the time evolution and explaining the effects of the different storage conditions were highlighted. Finally, a PCA analysis revealed that VOCs profile significantly correlated with sensory attributes.
