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Funding Information: This study had the support of Fundação para a Ciência e Tecnologia (FCT) through the PhD grant awarded to C.A. (SFRH/BD/62211/2009). C.A. also acknowledges financial support from FCT, through the strategic project UIDB/00329/2020 granted to cE3c-Centre of Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa. M.A. and M.M.-M. also acknowledge financial support from FCT, through the strategic project UIDB/04129/2020 granted to LEAF-Linking Landscape, Environment, Agriculture and Food Research Unit. E.M.G. acknowledges financial support from FCT, through the strategic project UIDB/04035/2020 granted to GeoBioTec Research Institute. Publisher Copyright: © 2022 by the authors. Fresh-cut fruits and vegetables, as near-fresh foods, are a quick and easy solution to a healthy and balanced diet. The rapid degradation of nutritional and sensory quality during the processing and storage of a product is critical and plant-type-dependent. The introduction of disruptive technological solutions in fresh-cut processing, which could maintain fresh-like quality with less environmental impact, is an emerging research concept. The application of abiotic stress treatments (heat shock and UV-C) induces metabolic responses and microbial effects in plant tissues, potentially slowing down several quality senescence pathways. The previously selected combined and single effects of heat shock (100 °C/45 s; in the whole root) and UV-C (2.5 kJ/m2) treatments and two packaging conditions (oriented polypropylene (OPP) vs. micro-perforated OPP films) on controlling critical degradation pathways of fresh-cut carrots and on promoting bioactive and sensory quality during storage (5 °C, 14 days) were studied. Among the tested combinations, synergistic effects on the quality retention of fresh-cut carrots were only attained for applying heat shock associated with micro-perforated OPP film packaging. Its effects on reducing (3.3 Log10 CFU/g) the initial contamination and controlling microbiological spoilage (counts below the threshold limit of 7.5 Log10 CFU/g), increasing the bioactive content (38% and 72% in total phenolic content and chlorogenic acid, respectively), and preserving fresh quality attributes prove to be a viable alternative technology for shredded carrot processing. publishersversion published

Funding Information: Funding: This research was funded by national funds from PDR2020-101-031501_59 no.—101 Green-Taste: “Development of new food products based on unripened industrial tomatoes”. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Lactic fermentation of unripe green tomatoes as a tool to produce food ingredients is a viable alternative for adding value to industrial tomatoes unsuitable for processing and left in large quantities in the fields. Fermentation using starter cultures isolated from the fruit (plant-matrix adapted) can have advantages over allochthonous strains in obtaining fermented products with sensory acceptability and potentially probiotic characteristics. This paper details the characterisation of the unripe green tomato lactic microbiota to screen LAB strains for use as starter cultures in fermentation processes, along with LAB strains available from INIAV’s collection. Morphological, biochemical (API system), and genomic (16S rDNA gene sequencing) identification showed that the dominant LAB genera in unripe green tomato are Lactiplantibacillus, Leuconostoc, and Weissella. Among nine tested strains, autochthonous Lactiplantibacillus plantarum and allochthonous Weissella paramesenteroides showed tolerance to added solanine (200 ppm) and the best in vitro probiotic potential. The results indicate that the two LAB strains are promising candidates for manufacturing probiotic fermented foods from unripe green tomatoes. publishersversion published

In this study we evaluated the effect of abiotic stresses, peeling and shredding, in different carrot tissues as a phenolic synthesis elicitor to improve bioactive quality of shredded carrot as a fresh-cut. The phenolic content (TPC) present in carrot peels (2954 mg kg−1) is up to ∼6 times higher than that of inner tissues (762 and 510 mg kg−1 for cortical parenchyma and vascular tissues, respectively). However, the effect of peel removal is mitigated by the respective tissue proportion in the root (∼11% for peel and ∼89% for inner tissues). Phenolic biosynthesis was verified in all carrot tissues and even when peel was removed, inner tissues were able to significantly accumulate phenolics during low temperature storage (5 °C, 10 d), with increases of 155% (compared to day 0). As key enzyme of the phenylpropanoid pathway, phenolic biosynthesis, in inner tissues, was confirmed by the phenylalanine-ammonia lyase (PAL) activity increase (p

This study evaluated the effect of water heat treatment (WHT, immersion in a water bath at 40C – 30 min) application in alternative to the conventional decontamination treatment of chlorinated water (150 ppm at 5C, pH 6.5 during 2 min) on tomato (cv. Zinac) at two maturity stages (turning and pink). Physiochemical attributes, enzymatic activities and microbial load were evaluated after treatments and during 14 days of storage at 10C. The WHT applied was very effective on microbial reduction and delayed physiochemical changes of tomato, namely firmness loss and red color development during storage period, especially at turning maturity stage. Based on the firmness parameter, shelf-life of control and WHT samples were determined. Our results provide strong evidence that postharvest WHT (40C – 30 min) for tomato fruits at turning maturity stage guarantees the overall quality at 10C twice as long of fruits washed with chlorinated water. Practical Applications Tomato is a popular fruit due to its high nutritional value and culinary versatility. However, tomato shelf-life is limited, especially if commercialized in an advanced maturity stage. Water heat treatment (WHT) is a promised postharvest processing to extend quality of fresh crop. WHT (40C – 30 min) applied to whole tomato (cv. “Zinac”) was found to be effective for microbial reduction and guarantees its overall quality at 10C for a double period, especially in early maturity stages, compared with conventional treatments, without presenting the chemical risks associated to by-products of chlorinated water.

The effects of storage at different temperatures (2, 5, 10, 15, and 20 degrees C) conditions on whole tomato (Solanum lycopersicum, cv. 'Zinac', fruits harvested at mature-green stage) quality parameters, such as colour, chilling injury, firmness, weight loss and total phenolic content, were investigated during a month period. Storage at all temperatures had significant impact on the quality parameters analysed. Significant alterations in tomato green colour, firmness and weight loss were observed. The results also revealed a slight increase in the total phenolic content, and that refrigeration storage at 2 and 5 degrees C induced chilling injuries. A fractional conversion model fitted well the experimental data on colour parameters (a. and degrees h value), firmness and weight loss. The storage temperature effect was successfully described by the Arrhenius law. These results represent a good predictive tool for tomato quality estimation along the food chain.

Abiotic stresses such as heat shock and UV-C irradiation can be used to induce synthesis of bioactive compounds and to prevent decay in fresh-cut fruits and vegetables. This study aimed to evaluate the effects of heat shock and UV-C radiation stress treatments, applied in whole carrots, on the overall quality of fresh-cut carrot cv. Nantes during storage (5 °C). Heat shock (HS, 100 °C/45 s) and UV-C (0.78 ± 0.36 kJ/m2) treated samples had higher phenolic content and exhibited reduced POD activities during storage when compared to control (Ctr) samples (200 mg/L free chlorine/1 min). All samples showed reduced carotenoid content considering raw material. Nonetheless, UV samples registered a three-fold increase in carotenoid content in subsequent storage. Fresh-cut carrot colour showed a continuous increase in whiteness index (WI) values during storage regardless of treatment without impairing visual quality. Respiratory metabolism was affected by both abiotic stress treatments since reduced O2/CO2 rates were found, more significant in HS samples. The decontamination effect was more expressive in HS samples, where a 2.5 Log10 cfu/g reduction in initial microbial load and reduced microbial growth were achieved.

Textural changes during fruit ripening have been attributed to pectin degradation due to pectic enzymes such as pectinmethylesterase (PME, EC 3.1.1.11). PME catalyzes the de-esterification of pectin, a complex mixture of polysaccharides, namely methyl esterified polygalacturonic acid, with the release of hydrogen and methanol, producing shorter chains causing drastic losses in firmness. Thus, control of PME activity in fruits aiming at texture maintenance and/or improvement is extremely important to the food industry. However, PME activity and properties are dependent on product, environmental and physico-chemical conditions, such as pH and temperature. Therefore, the aim of the present work was to optimize the pectinmethylesterase (PME) enzyme assay from tomato (Solanum lycopersicum 'Zinac') fruits, and determine its kinetics behavior and thermal stability. The highest PME activity was found with a 1.0 M of NaCl extraction solution, with 0.5% citrus pectin, and revealed optima of temperature at 60°C and pH of 8.8. The low kM value (0.011%) for tomato PME describes the high affinity between enzyme and substrate (citrus pectin), whereas the obtained Vmax value (0.712 U mg-1) relates to the enzyme quantity present in the reaction. The study of PME thermal stability showed two distinct behaviors: an increase of activity from 40 to 50°C and a decrease from 55 to 80°C. At 50°C/10 min an increase in activity up to 17% of activity was observed. At 60°C, about 50% of the activity still remained after heating for 25 min, and PME was completely inactivated at 80°C after 10 min. Data obtained in the temperature range of 55 to 80°C were also satisfactorily described by an Arrhenius first-order kinetic model. These results provide useful information about the different factors that affect tomato PME activity and may be used as a tool for firmness control during postharvest handling and fruit processing.

Response surface methodology based on a five-level, three-variable central composite rotatable design was used for modeling the effects of preheat treatments on fresh-cut “Rocha” pear quality. Studied variables were time (t: 0–150 min), temperature (T: 20–50C) and posttreatment storage time (St: 0–20 days, 5C). The quality-affecting parameters including color, firmness, pH, soluble solid content, and total ascorbic acid content were the monitored dependent variables. Results provide reasonable estimation of the impact of preheat treatments on the quality of fresh-cut “Rocha” pear and its shelf life. The time–temperature range of 33–41C during less than 20 min was selected as the conditions that best provided surface browning control, without impairing other studied quality parameters, with an estimated 8-day shelf life period. The achieved kinetic changes of polyphenoloxidase, partial reduction in enzyme activity (ca. 23%) and depletion of phenolic content (ca. 11%) could be responsible for the browning control. PRACTICAL APPLICATIONS Minimal processing, namely cutting operations, triggers physiological reactions which limit fresh-cut Rocha pear shelf life. Superficial browning is one of the major concerns to this industry, and new “clean” methodologies aiming at the inhibition of such reaction and maximization of the product shelf life will benefit not only from product marketability but also will respond to the consumers' demand of “chemical free” products. Heat treatments have been used to improve fresh-cut commodities' browning resistance. The present work evaluated the use of preheat treatments against this physiological disorder during storage. Results will provide an optimized preheat treatment that grants high-quality fresh-cut Rocha pear with suitable shelf life.

The effect of a pre-cut heat treatment (100 °C/45 s) as an alternative decontamination treatment to chlorinated-water (200 ppm active chlorine/1 min, 5 °C) was evaluated in minimally processed carrot (shredded). The quality of shredded carrots was studied just after minimal processing and during storage at 5 °C (10 days) by evaluating microbial (total mesophilic aerobic, yeast and moulds and lactic acid bacteria counts), physical–chemical (soluble solids content, pH, titratable acidity, whiteness index), physiological (peroxidase activity and headspace analysis) and sensorial attributes (colour, fresh-like appearance, aroma and general acceptance). The relationships between sensory perception of undesired changes, microbial contamination threshold, physico-chemical and physiological indices were investigated and compared between heat-treated and control samples. The use of heat in pre-cut carrot proved to be more efficient than chlorinated-water concerning microbial control (threshold concentration of 7 Log10 cfu g− 1), providing an acceptable fresh-like quality product during 10 days of storage (5 °C), which corresponds to a 3-day shelf-life extension compared to control samples. Heat-treated shredded carrot showed lower respiratory and POD activities than chlorinated samples suggesting that the use of heat provides a metabolic activity lowering effect besides the microbial effect which could be important to shelf-life extension of the fresh-cut product. Industrial relevance In minimally processed vegetables, namely in shredded carrot, chlorine solutions have been widely used by the industry for sanitization purposes. However, reduced microbiological efficiency allied to sensorial changes and eventual formation of carcinogenic chlorinated compounds pointed out the need for alternative decontamination methodologies. Also, the evermore conscious consumers are demanding minimization of the potentially negative impact of food processing on human health and the environment. From the practical experience of a fresh-cut industry directly involved in the R&D research project which supported this study, the marketability of minimally processed shredded carrot is limited due to rapid microbial growth and colour loss (decrease of orange intensity and/or whitening of the shreds). As a result, a pilot-plant scale study was performed, evaluating quality attributes of shredded carrot processed according to a clean pre-cut alternative decontamination process.

The effects of alternative decontamination processes to chlorine: ozonated-water (1 ppm/5 min), hot water (100 °C/45 s) and ultrasonication (45 kHz/1 min), applied pre- or post-cut in the technological diagram of minimal processing of carrots were tested. Ultrasonication in chlorinated-water and thermo-ultrasonication as combined processes applied just in pre-cut carrot were also tested. The initial microbial load reduction, soluble solids content, pH and sensorial attributes of shredded carrot just after processing were evaluated. Decontamination processes applied on pre-cut carrot provided maintenance of fresh-like sensorial quality, regardless the type of treatment, due to diminished leaching phenomena which is critical for shredded carrot. Chlorination, ozonization and ultrasonication achieved ca . 1 Log 10 reduction of initial microbial load. No additional decontamination effect in combined processes was observed. The use of heat in pre-cut carrot proved to be the most efficient process regarding microbial reduction (3 Log 10 units) providing, as well, an acceptable fresh-like quality product. Industrial relevance The major constraint for marketability of minimally processed shredded carrot is its limited shelf-life due to rapid microbial growth and colour loss (decrease of orange intensity and/or whitening of the shreds). These questions arise from the practical experience of a fresh-cut industry directly involved in the R&D research project which supported this study. Chlorine solutions have been widely used to sanitize fruit and vegetables in the fresh-cut industry. However, reduced microbiological efficiency allied to the eventual formation of carcinogenic chlorinated compounds pointed out the need for alternative methodologies. The present work aimed the evaluation of clean alternative decontamination processes applied both to pre- and post-cut carrot for the production of shredded carrot, operating under conditions of industrial practice at pilot-plant scale.

Res_por:Apresenta-se o resultado de prospeccoes intensivas efectuadas ao longo do curso da Ribeira da Meimoa (Fundao, Castelo Branco) e analisa-se a forma como o povoamento rural romano se encontra distribuido pela paisagem e se relaciona com os recursos naturais e o territorio construido.

The effect of ozonated water (0.5 ppm/5 min, 5°C) as an alternative decontamination treatment to chlorinated water (150 ppm active chlorine/1 min, 5°C) was evaluated in fresh-cut 'Rocha' pear (quarters). The quality of the product was studied just after minimal processing and during storage at 5°C (13 days) by evaluating microbial (total mesophilic aerobic, yeast and moulds and lactic acid bacteria counts), chemical parameters (soluble solids content and pH) and sensorial attributes (colour, firmness and general acceptance). The relationships between sensory perception of undesired changes, microbial contamination threshold and chemical indices were investigated and compared between both samples. No significant reduction of the initial microbial flora was observed in fresh-cut pear treated with ozonated and chlorinated water. Both samples also showed a very similar (P>0.05) microbial pattern during storage for all tested groups. No significant changes (P