1,720,995 research outputs found
Monitoring the effect of cutting blade sharpness on quality of fresh-cut product
No full textMechanical damage during processing operations such as peeling and cutting is one of the major factors affecting the quality and shelf life of the fresh cut produce. The intensity of mechanical damage is highly associated to the morphology of the cut tissue and to the sharpness of the cutting tool used. The degree of sharpness (DoS, defined as the required force exerted by the instrument to cut a reference body) is an important factor for an efficient cutting operation and a methodology has been developed in order to formulate an objective assessment method to be applied to evaluate cutting damage on fresh-cut products. To this aim, 3 kitchen knives (A, B and C) were used with 8 DoS values (from 1, sharpest to 8, bluntest) to cut silicon plugs as reference bodies with cross-section diameters of 6 and 8-mm. For the 6-mm plugs and knife A the force varied from 16.2±0.5 N (DoS=1) to 93.6±7.0 N (DoS=8), for knife B from 17.9±0.4 (DoS=1) to 80.1±6.1 N (DoS=8), and for knife C from 17.4±0.9 (DoS=1) to 155.3±2.0 N (DoS=8). As for the 8-mm plugs forces ranged for knife A, B and C from 26.0±1.1 N (DoS=1) to 105.6±7.6 N (DoS=8), from 29.0±1.3 (DoS=1) to 104.6±6.5 N (DoS=8) and from 26.1±0.7 (DoS=1) to 195.9±11.7 N (DoS=8) respectively. Cutting force mean values for all knives and DoS resulted statistically significant in relation to standard deviation values. Following, kitchen knives at 3 different DoS corresponding to 30, 90, and 140 N of cutting forces, labeled as DoS1, DoS2 and DoS3 respectively, were used to cut fresh apples and quality of the product was evaluated during storage in terms of changes in the visual appearance (sensorial), CIELAB values and chemical response. It was confirmed that color changes in terms of browning were higher as the DoS decreased with data significantly fitting an exponential relation. These and the other results indicate a potential for further research aimed to define the threshold in terms of sharpness of cutting tools after which the effects on quality of the product would be not compatible with its commercial value
Modeling Shelf-Life of Packaged Ready to eat Fruits and Vegetables with Reference to the Fate of Nutritional Compounds
No full textAssessment of eggplant freshness using nondestructive techniques
No full textEggplant fruit is a chilling injury sensitive vegetable, which should be stored at temperature of 12°C; however, at this temperature, the metabolism of the fruit is still intensively active and therefore significant quality deterioration may be induced. Since these quality losses can be difficultly detected by eyes, objective of this study was to develop a novel non-destructive method to estimate freshness of eggplants. Eggplant fruits ('Fantasy') were harvested from a commercial farm in Lecce, Italy, during July 2017. Fruits were stored at 12°C for 10 days. Every 2 days, fruits from were sampled and left at room temperature (20°C), for one additional day, simulating one-day shelf life at the market. Color spectra (360-740 nm), Fourier Transform (FT)-NIR spectra (800-2777 nm) and hyperspectral images (HSI) in the Vis-NIR range (400-1000 nm) were also acquired on each fruit. Partial least square regression analyses were carried out between the data collected and the storage days and appropriate models were built, allowing safe assessment of the freshness of the fruits. According to the results based on whole wavelength ranges, storage days correlated very well with both the FT-NIR spectra and the hyperspectral data extracted from the Vis-NIR imaging system (RC>0.98, RCV>0.94, RMSEC<0.4 and RMSECV<0.8), in contrast to the color measurements with lower RC and RCV values and significantly high root means square errors (1.5 and 1.8, respectively). Moreover, after conducting SPA as a variable selection method, classification models could almost keep the same performance. The results of this study may set the basis to develop a protocol allowing a rapid screening and sorting of eggplants according to their postharvest freshness at distribution center or even upon the reception in the retail market
Evaluation of quality and storability of “Italia” table grapes kept on the vine in comparison to cold storage techniques
No full textThe aim of the study was to compare the quality of table grapes (cv. Italia) held on the vine compared to grapes stored in cold rooms with or without modified-atmosphere packaging (MAP). The grapes were harvested from 12 plants in 2 vineyards in the same area, differing for the age of the plant. Four-and a fourteen-year-old vines were cultivated with the “Apulia tendone” system. After the first harvest, grapes were divided into small clusters and used for storage treatments in air and in MAP. Samples of 400 g were packaged in polypropylene (PP) trays sealed with a polypropylene/polyamide (PP/PA) film with 20% CO2 in air. MAP and control samples were then stored in the same cold room at 0◦ C. Initially and after 8, 21, and 28 days, grapes stored in air and MAP were compared to fresh harvested grapes, stored on the plants. Quality attributes included color, texture, maturity index, phenols, antioxidant activity, sugars, organic acids, sensory parameters, and volatile compounds. The results obtained demonstrated that grapes held on the plant and in MAP showed better quality in terms of appearance scores compared to grapes stored in air. In particular, the application of high CO2 contributed to reduce the deterioration rate of the clusters, minimizing weight loss, and delaying degradation processes, and this particularly for grapes from the 14-year-old vine, where grapes held on the plant degraded faster than grapes in the younger vines. Most volatile compounds did not change their concentration with the storage treatment, except for ethyl acetate and ethanol, which increased in MAP at the end of storage, and to some compound responsible for green odor. In conclusion, keeping the grapes on the plant can be considered a good agronomic practice to preserve the quality, whereas MAP can be applied to better maintain postharvest quality of the product throughout storage and distribution
Innovative approaches to improve quality and safety of fresh minimally-processed fruit and vegetables
No full textFresh minimally-processed fruit and vegetables are constituted by living cell tissue, rapidly metabolizing, especially when peeled and cut in portions for higher convenience. For this reason quality attributes (i.e., appearance, texture, flavor, and nutritional value) degrade very fast and shelf life is often a matter of days or, in some cases, of weeks. On the other hand the preparation process does not include a so-called “killing step”, or a treatment which determines a negligible final microbial count. In fact for this kind of product freshness itself is a limit which does not allow the application of eradicating treatments. A number of priorities are on top of the list of the fresh-cut industry which may have a direct influence on consumers. Safety of course, not only in relation to microbial contamination but also related to other possible issues (i.e., chemical contamination and possible presence of animal parasites), and also quality, more and more referring to nutritional value and taste and flavor. These two main objectives are often associated to the extension of the shelf-life. Finally for a food industry with a very intense use of water, plastic, and energy kg-1 of final product, sustainability of the whole chain represents another important issue in order to reduce the impact on the environment and, last but not least, on production costs. For all these reasons fresh minimally-processed produce represents a very interesting food system where the need of improvements is of paramount importance. In the last few years R&D strategies have been diverse ranging from the proteomic approach to nanotechnology, including non-destructive tools, predictive models and green-chemistry applications to develop important innovations in processing, packaging, and logistic. Some of these approaches will be discussed through some of the results of two large multi-partner R&D projects (i.e., QUAFETY co-funded by European Commission, and OFRALSER co-funded by Italy’s government) which have focused on fresh minimally-processed fruit and vegetables, with a multi-disciplinary approach and a particular attention to dissemination of results
Operating conditions for microwave application throughout production process to reduce microbial load of fresh-cut apples
No full textConsumers increasingly demand for convenient and healthy products such as fresh-cut fruits and vegetables. An important issue is the product safety, conventionally controlled using chemical sanitizing agents. High power/short time microwave-assisted heating could be used to improve quality and safety of high-convenience fresh produce by delaying quality losses and reducing microbial load, the use of sanitizing agents. Microwave as a postharvest treatment has not yet been largely studied. Application of mild-heat treatments is used in this work at different stages of the production process in order to prolong the shelf-life and improve quality and safety of fresh-cut apples. Two power/time combinations were applied before and after washing the apple slices (35 s/300 Watt of output power and 10 s (100 W)-1). Physico-chemical, organoleptic and microbiological analysis were carried out on representative samples after treatment and during storage time. Results showed that the treatment 300 W (35 s)-1after washing, gave a greater microbial reduction compared to control samples washed with 30 ppm NaClO, without adverse effect on nutritional aspects. Microwaving was applied before and after packaging and it was observed that apple slices treated after packaging reached 1.4 log CFU g-1reduction of microbial load during 14 days storage. However, the samples treated and packaged showed a slight decrease of visual quality. Additional treatment with calcium ascorbate or natural anti-browning agents may be considered in order to maintain product quality. From the results obtained it is possible to conclude that microwave treatment, eventually together with anti-browning treatment, could represent a good, effective and sustainable alternative to NaClO in terms of reduction of chemicals and water consumption
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