Elsa Margarida nunes Leal Goncalves
Verified @gmail.com
Unidade de Tecnologia e Inovação
Instituto Nacional de Investigação Agrária e Veterinária
Dr. Elsa M. Gonçalves received a “Licenciatura” (5 years BEng degree) in Food Engineering in 1991 from the College of Biotechnology, Catholic University of Portugal. She obtained her Ph.D. degree in 2011, in Biotechnology with specialisation in Science and Food Engineering at the College of Biotechnology, Catholic University of Portugal.
From 1992 to 2013, Dr. Elsa M. Gonçalves worked as a Researcher at the Department “Ciencias e Tecnologia dos Alimentos” of the “Instituto Nacional de Investigação Agrária e Veterinária”. Areas of research interest included enhancing nutritive contents of foods, innovative and traditional preservation techniques, packaging and shelf life estimation, modelling of physic & biochemical proprieties, quality systems, risk assessment, food safety and quality. She has published extensively in these fields. Dr. Elsa M. Gonçalves’s research work involved collaborative projects with the Food Industry, Universities and other organizations.
Since September 2013 unt
EDUCATION
“Licenciatura” (5 years BEng degree) in Food Engineering in 1991 from the College of Biotechnology, Catholic University of Portugal. She obtained her Ph.D. degree in 2011, in Biotechnology with specialisation in Science and Food Engineering at the College of Biotechnology, Catholic University of Portugal.
RESEARCH INTERESTS
Food Science; Food Technology, Health; Quality, Sensorial analysis; waste; Sustentability
FUTURE PROJECTS
Reuse foods
Applications Invited
Novel thermal tehnology
Applications Invited
Scopus Publications
Scopus Publications
K. Teixeira, E. Gonçalves, P. Carvalho, A. Graça, and A. Martins
International Society for Horticultural Science (ISHS)
Nelson Pereira, Mahsa Farrokhi, Manuela Vida, Manuela Lageiro, Ana Cristina Ramos, Margarida C. Vieira, Carla Alegria, Elsa M. Gonçalves, and Marta Abreu
MDPI AG
In this study, the lactic fermentation of immature tomatoes as a tool for food ingredient production was evaluated as a circular economy-oriented alternative for valorising industrial tomatoes that are unsuitable for processing and which have wasted away in large quantities in the field. Two lactic acid bacteria (LAB) were assessed as starter cultures in an immature tomato pulp fermentation to produce functional food ingredients with probiotic potential. The first trial evaluated the probiotic character of Lactiplantibacillus plantarum (LAB97, isolated from immature tomato microbiota) and Weissella paramesenteroides (C1090, from the INIAV collection) through in vitro gastrointestinal digestion simulation. The results showed that LAB97 and C1090 met the probiotic potential viability criterion by maintaining 6 log10 CFU/mL counts after in vitro simulation. The second trial assessed the LAB starters’ fermentative ability. Partially decontaminated (110 °C/2 min) immature tomato pulp was used to prepare the individually inoculated samples (Id: LAB97 and C1090). Non-inoculated samples, both with and without thermal treatment (Id: CTR-TT and CTR-NTT, respectively), were prepared as the controls. Fermentation was undertaken (25 °C, 100 rpm) for 14 days. Throughout storage (0, 24, 48, 72 h, 7, and 14 days), all the samples were tested for LAB and Y&M counts, titratable acidity (TA), solid soluble content (SSC), total phenolic content (TPC), antioxidant capacity (AOx), as well as for organic acids and phenolic profiles, and CIELab colour and sensory evaluation (14th day). The LAB growth reached ca. 9 log10 CFU/mL for all samples after 72 h. The LAB97 samples had an earlier and higher acidification rate than the remaining ones, and they were highly correlated to lactic acid increments. The inoculated samples showed a faster and higher decrease rate in their SSC levels when compared to the controls. A nearly two-fold increase (p < 0.05) during the fermentation, over time, was observed in all samples’ AOx and TPC (p < 0.05, r = 0.93; similar pattern). The LAB97 samples obtained the best sensory acceptance for flavour and overall appreciation scores when compared to the others. In conclusion, the L. plantarum LAB97 starter culture was selected as a novel probiotic candidate to obtain a potential probiotic ingredient from immature tomato fruits.
Elsa M. Gonçalves, Nelson Pereira, Mafalda Silva, Nuno Alvarenga, Ana Cristina Ramos, Carla Alegria, and Marta Abreu
MDPI AG
The drying process is an essential thermal process for preserving vegetables and can be used in developing dried products as healthy alternative snacks. The effects of air-drying conditions using a convection dryer with hot air at different temperatures (60°, 65°, 70°, 75°, and 80 °C, in the range 5–200 min, at a fixed air speed of 2.3 m/s) were tested on the quality of slices (2.0 ± 0.1 mm) of dried sweet potato (Bellevue PBR). For each time and temperature, drying condition, physicochemical parameters (moisture content, CIELab color, texture parameters, total phenolic and carotenoid contents) and a sensory evaluation by a panel at the last drying period (200 min) were assessed. Drying time was shown to have a more significant effect than temperature on the quality of dried sweet potato as a snack, except for carotenoid content. Given the raw tuber content, thermal degradation (p < 0.05) of total phenolic compounds (about 70%), regardless of tested conditions, contrasted with the higher stability of total carotenoids (<30%). The dried product, under optimal conditions (≥75 °C for 200 min), achieved a moisture content (≤10%) suitable for preservation, providing a crispy texture with favourable sensory acceptance and providing a carotenoid content similar to the raw product.
Diana Daccak, Fernando C. Lidon, Inês Carmo Luís, Ana Coelho Marques, Ana Rita F. Coelho, Cláudia Campos Pessoa, João Caleiro, José C. Ramalho, António E. Leitão, Maria José Silva,et al.
MDPI AG
Nowadays, there is a growing concern about micronutrient deficits in food products, with agronomic biofortification being considered a mitigation strategy. In this context, as Zn is essential for growth and maintenance of human health, a workflow for the biofortification of grapes from the Vitis vinifera variety Fernão Pires, which contains this nutrient, was carried out considering the soil properties of the vineyard. Additionally, Zn accumulation in the tissues of the grapes and the implications for some quality parameters and on winemaking were assessed. Vines were sprayed three times with ZnO and ZnSO4 at concentrations of 150, 450, and 900 g ha−1 during the production cycle. Physiological data were obtained through chlorophyll a fluorescence data, to access the potential symptoms of toxicity. At harvest, treated grapes revealed significant increases of Zn concentration relative to the control, being more pronounced for ZnO and ZnSO4 in the skin and seeds, respectively. After winemaking, an increase was also found regarding the control (i.e., 1.59-fold with ZnSO4-450 g ha−1). The contents of the sugars and fatty acids, as well as the colorimetric analyses, were also assessed, but significant variations were not found among treatments. In general, Zn biofortification increased with ZnO and ZnSO4, without significantly affecting the physicochemical characteristics of grapes.
Carla Alegria, Elsa M. Gonçalves, Margarida Moldão-Martins, and Marta Abreu
MDPI AG
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.
Carla Alegria, Elsa M Gonçalves, Margarida Moldão-Martins, and Marta Abreu
SAGE Publications
In fresh-cut vegetables, plant tissues are often challenged by (a)biotic stresses that act in combination, and the response to combinatorial stresses differs from that triggered by each individually. Phenolic induction by wounding is a known response contributing to increase products phenolic content. Heat application is a promising treatment in minimal processing, and its interference on the wound-induced response is produce-dependent. In carrot, two-combined stress effects were evaluated: peel removal vs. shredding, and heat application (100 °C/45 s) vs. shredding, on changes in total phenolic content (TPC) during 10 days (5 °C). By applying the first stress combination, a decrease in TPC was verified on day 0 (∼50%), ascribed to the high phenolic content of peels. Recovery of initial fresh carrot levels was achieved after 7 days owing to phenolic biosynthesis induced by shredding. For the second combination, changes in TPC, phenylalanine-ammonia-lyase (PAL), and peroxidase (POD) activity of untreated (Ctr) and heat-treated (HS) peeled shredded carrot samples were evaluated during 10 days. The heat-shock did not suppress phenolic biosynthesis promoted by PAL, although there was a two-day delay in TPC increments. Notwithstanding, phenolic accumulation after 10 days exceeded raw material TPC content. Also, the decrease in POD activity (30%) could influence quality degradation during storage.
Elsa Gonçalves and Antero Martins
Elsevier
Nelson Pereira, Carla Alegria, Cristina Aleixo, Paula Martins, Elsa M. Gonçalves, and Marta Abreu
MDPI AG
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.
João Mestre Dias, Patricia Lage, Nuno Alvarenga, João Garcia, Joana Borrega, Maria Teresa Santos, Célia Lampreia, Luis Coelho, João Pássaro, João Martins,et al.
Springer Science and Business Media LLC
“Queijo de Évora” is a traditional Portuguese cheese from raw ewe’s milk and granted with PDO label. It is ripened traditionally in rooms with empirical control of temperature and humidity. Nowadays, almost all cheese factories use rooms with temperature and humidity control, but still a significant heterogeneity among cheeses is acknowledged due to unequal distribution of environmental conditions. This paper discusses the influence of the environmental conditions on the ripening of Queijo de Évora, including the application of computational fluid dynamics in steady state conditions. Experimental data was obtained in cheeses ripened along the traditional ripening cycle, in different locations. A significant influence of environmental conditions was observed, especially air velocity and humidity, affecting physical–chemical, microbiological and sensory characteristics. Locations with higher air velocity, presented cheeses with lower moisture content, higher mesophilic bacteria count, darker appearance and higher number of holes. Locations with higher humidity presented cheeses with lower scores on some sensorial parameters like appearance, firmness and intensity of odor. The results of computational fluid dynamics made possible the identification of areas in and around the cheese stacks were the air distribution is less than adequate or uneven, which may influence the evolution of cheese during ripening.
Cláudia Campos Pessoa, Fernando Cebola Lidon, Ana Rita F. Coelho, João Cravidão Caleiro, Ana Coelho Marques, Inês Carmo Luís, José Carlos Kullberg, Paulo Legoinha, Maria da Graça Brito, José Cochicho Ramalho,et al.
Elsevier BV
Abstract Low dietary intake of Ca in humans has been epidemiologically linked to various diseases, which can have serious health consequences over time. Accordingly, the development of an agronomic itinerary for Ca biofortification of Rocha pears and the assessment of physicochemical deviations prompted this study. Two orchards with contrasting soil and water characteristics were selected, characterized through orthophotomaping and, during fruits development, leaves were sprayed twice with Ca(NO3)2 (0.1, 0.3 and 0.6 kg ha−1) or CaCl2 (0.4, 0.8 and 1.6 kg ha−1), followed by pulverization only with CaCl2 (first once with 4 kg ha−1 and then four times with 8 kg ha−1). During fruits development net photosynthesis, stomatal conductance, transpiration rates, instantaneous and water use efficiency, only showed minor deviations, which indicated that the threshold of toxicity was not surpassed. Calcium contents varied during fruits development and at harvesting the average biofortification index varied between 47 %–63 % and 24 %–59 % in each of the orchards. Besides, the equatorial region of the fruits showed for all treatments (substantially in Ca treated samples) higher Ca contents in the epidermal and in the central regions. Fresh and heat-treated fruits (in a thermomix at 90 °C, during 10 min) biofortified with Ca only revealed minor differences and the sensory acceptability did not vary markedly. It is concluded that, although prevailing a heterogeneous distribution of Ca in fruit tissues, high indexes of biofortification in Rocha pears can be prompt in the orchards, without substantial physicochemical changes. Accordingly, agronomic biofortification with Ca can be used as a strategy for benefiting consumer’s health.
Joaquina Pinheiro, Elsa M. Gonçalves, and Rui Ganhão
Springer International Publishing
Elsa M. Gonçalves, Marta Abreu, Joaquina Pinheiro, Teresa R. S. Brandão, and Cristina L. M. Silva
Wiley
Elsa M. Gonçalves, Isa Raposo, Joaquina Pinheiro, Carla Alegria, Margarida Moldão, and Marta Abreu
Faculty of Food and Agriculture, United Arab Emirates University
The present work aimed to evaluate, through thermal degradation kinetics (80 °C to 98 °C in time intervals of 0.5 to 25 min), the effects of different thermal treatments on the biochemical, physicochemical, sensory and microbiological parameters of two mixed fruit and vegetable pulps, a yellow and a red one. The evaluated fruit and vegetable pulps resulted from the mixture of different fruits and vegetables proportions (pineapple, beetroot, strawberry and lemon juice) added to a 50% (p/p) pear-based pulp to maximize their bioactivity, physicochemical stability and sensorial acceptance. Evaluated quality parameters included the determination of peroxidase activity (POD), pH, soluble solids content (SSC), total phenolic content (TPC), CIELab colour, sensory evaluation (colour, taste and aroma) and total mesophilic aerobic counts (TAPC). Regarding heat treatments optimization for both pulps with lower pH, it was concluded that higher temperature treatments (90 to 98 °C) applied over a shorter time (less than 5 min) were more effective to inactivate POD, to reduce the initial microbial load (>2 log10 cycles) and to maximize sensorial attributes. In both mix pulps, total phenolic content (TPC) was not significantly influenced by the different applied time-temperature binomials. From the degradation kinetic models and as an example, it was possible to conclude that POD followed a 1st order kinetic, where the temperature effect was well fitted to the Arrhenius equation. The results allowed to obtain optimized time-temperature binomials for each pulp to simultaneously achieve POD enzyme inactivation, microbial reduction, and maximization of quality parameters relatively to fresh pulps, 90 °C/5 min and 98 °C/2.5 min, for the yellow pulp and red pulp, respectively.
Joaquina Pinheiro, Rui Ganhão, Elsa M. Gonçalves, and Cristina L.M. Silva
MDPI AG
Tomatoes are a popular and rich fruit due to their nutritional and bioactive composition as vitamins, antioxidants, and phenolics contributing to the promotion of consumer health. For this reason, emerging postharvest technologies need to be evaluated to achieve the maintenance of sensorial and quality-related characteristics, like color and texture, while aiding to fruit decontamination. Optimization of thermosonication as postharvest treatments on whole, mature-green tomatoes (cv. “Zinac”) to improve quality (color, texture, total phenolic content, and weight loss) was performed by response surface methodology. Temperature (32–48 °C), treatment time (13–47 min), and storage period at 10 °C (1–15 days) at constant ultrasound frequency (45 kHz; 80% power level), were the independent variables. In general, thermosonication delayed tomato color changes while achieving total phenolic content increase and good overall quality. Three optimal thermosonication conditions were selected and validated (32 °C-13 min, 35 °C-20 min and 40 °C-30 min). The most suitable thermosonication condition that promoted a longer storage while keeping a high-quality standard was at 40 °C during 30 min. This study demonstrated that thermosonication provides an effective alternative methodology to guarantee tomato quality without significant change during the expected postharvest period.
Carla Alegria, Elsa M. Gonçalves, Margarida Moldão-Martins, Luis Cisneros-Zevallos, and Marta Abreu
Elsevier BV
Abstract 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
Joaquina C. Pinheiro, Carla S. M. Alegria, Marta M. M. N. Abreu, Elsa M. Gonçalves, and Cristina L. M. Silva
Springer Science and Business Media LLC
Previously optimised postharvest treatments were compared to conventional chlorinated water treatment in terms of their effects on the overall quality of tomato (‘Zinac’) during storage at 10 °C. The treatments in question were water heat treatment (WHT = 40 °C, 30 min), ultrasounds (US = 45 kHz, 80 %, 30 min), thermosonication (TS = 40 °C, 30 min, 45 kHz, 80 %) and ultraviolet irradiation (UV-C: 0.97 kJ m−2). The quality factors evaluated were colour, texture, sensorial analysis, mass loss, antioxidant capacity, total phenolic content, peroxidase and pectin methylesterase enzymatic activities, and microbial load reduction. The results demonstrate that all treatments tested preserve tomato quality to some extent during storage at 10 °C. WHT, TS and UV-C proved to be more efficient on minimising colour and texture changes with the additional advantage of microbial load reduction, leading to a shelf life extension when compared to control trials. However, at the end of storage, with exception of WHT samples, the antioxidant activity and phenolic content of treated samples was lower than for control samples. Moreover, sensorial results were well correlated with instrumental colour experimental data. This study presents alternative postharvest technologies that improve tomato (Zinac) quality during shelf life period and minimise the negative impact of conventional chlorinated water on human safety, health and environment.
Joaquina Pinheiro, Carla Alegria, Marta Abreu, Manuela Sol, Elsa M. Gonçalves, and Cristina L.M. Silva
Wiley
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.
Joaquina Pinheiro, Carla Alegria, Marta Abreu, Elsa M. Gonçalves, and Cristina L.M. Silva
Elsevier BV
Whole tomato fruits were treated at ultrasonic power levels from 10% to 100%, and at a constant frequency of 45 kHz, for different times (1-19 min). A central composite rotatable design (CCRD) was applied to optimise ultrasonic treatments for tomato quality (colour, texture and total phenolic content (TPC)) maintenance. According to response surface analysis, the optimal treatment parameters were 55%_10 min, 80%_15 min and 100%_19 min. At these conditions, and especially at higher power levels, a maximum retention of colour and texture, as well as an increase of TPC and microbial reduction were obtained in comparison with untreated fruits during 15 storage days at 10°C. The ultrasounds treatment was found to be effective in delaying colour development and texture losses, preserving sensorial quality of whole tomato, with increase of TPC and microbial load reduction. Moreover, this postharvest treatment can be used as an alternative for extending fresh fruits shelf-life.
Joaquina Pinheiro, Carla Alegria, Marta Abreu, Elsa M. Gonçalves, and Cristina L. M. Silva
Springer Science and Business Media LLC
The effect of UV-C treatments (0.32, 0.97, 2.56, 4.16 and 4.83 kJ.m−2 at 254 nm) on the physical-chemical properties [colour, texture, total phenolic content (TPC), weight loss (WL)], and mesophylic counts of whole tomato, was evaluated during 15 days at 10 °C. During storage, the Ctr samples acquired faster red colour than all UV-C samples (higher a* and lower °h values). Comparing texture of Ctr and UV-C samples at 15th storage day, an increase of 9 and 8 % on firmness of treated samples at low UV-C intensities (0.32 and 0.97 kJ.m−2, respectively) was observed. At the end of the storage, Ctr samples showed ca. 4 Log10 of mesophylic load, and the samples treated at 0.97 and 4.83 kJ.m−2 revealed the lowest microbial load (1.9 and 3.2 Log10, respectively). These results indicate that UV-C radiation, at an appropriate dose, combined with low storage temperature (10 °C) are an effective method to preserve the postharvest life of tomato, without adversely affecting quality parameters.
J. Pinheiro
CABI Publishing
Abstract Fresh tomato (Solanum lycopersicum) is one of the most consumed fruits and the preservation of its quality and shelf-life extension is a continuous challenge. An understanding of fruit deterioration factors allows the investigation of new approaches to reach this objective. Fruit preservation is achieved by destroying enzymes and micro-organisms, and reducing physiological disorders, using treatments such as chlorinated water (HIPO), ozone, low or high temperatures, ultrasounds, UV-C radiation, modified atmosphere packaging, edible coatings and 1-methylcyclopropene. In this review, a description of action, advantages and disadvantages of each preservation treatment, and corresponding effects on tomato quality and safety are presented. The development of a green technology for tomato has advantages for all fresh chain interventions, with direct or indirect impacts on human health.
Teresa R. S. Brandão, Maria M. Gil, Fátima A. Miller, Elsa M. Gonçalves, and Cristina L. M. Silva
Springer US
Consumers expect that food products will be safe and convenient to use and still have all the qualities of a fresh product. Foods often undergo processing, which has three major aims: to make food safe while providing products with the highest quality attributes, to transform food into forms that are more convenient or more appealing, and to extend shelf-life. Food processes such as thermally based ones (i.e. pasteurization and drying) or frozen storage occur in time-varying temperature conditions. Mathematical models that describe/predict changes in processed food characteristics with accuracy and precision in realistic, dynamic conditions are important tools in the development of new products and control systems.
Joaquina Pinheiro, Carla Alegria, Marta Abreu, Elsa M. Gonçalves, and Cristina L.M. Silva
Elsevier BV
Abstract The effects of storage at different temperatures (2, 5, 10, 15 and 20 °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 °C induced chilling injuries. A fractional conversion model fitted well the experimental data on colour parameters ( a * and °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.
M. Abreu, C. Alegria, E.M. Gonçalves, J. Pinheiro, M. Moldão-Martins, and J. Empis
International Society for Horticultural Science (ISHS)
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<0.05) were observed in the soluble solids content and pH of either fresh-cut samples during storage. However, sensory quality of fresh-cut pear treated with ozonated water was better than that treated with chlorine.
M. Abreu, C. Alegria, E.M. Gonçalves, J. Pinheiro, M. Moldão-Martins, and J. Empis
International Society for Horticultural Science (ISHS)
J. Pinheiro, C.L.M. Silva, C. Alegria, M. Abreu, and E.M. Gonçalves
International Society for Horticultural Science (ISHS)