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- Thermal and non-thermal Cantaloupe melon juice pasteurization: Assessment of the impact of ozone exposure on microbiological, physicochemical and bioactive characteristicsPublication . Sroy, Sengly; Fundo, Joana F.; Miller, Fátima A.; Brandão, Teresa R.S.; Silva, Cristina L. M.
- Physicochemical and bioactive caracterisation of edible and waste parts of “piel de sapo” melonPublication . Miller, Fátima Alves; Fundo, Joana Freitas; Garcia, Ester; Santos, João Rodrigo; Silva, Cristina Luisa Miranda; Brandão, Teresa Ribeiro SilvaSeveral scientific studies point fruits as rich sources of antioxidants but mainly focus on their edible part. However, fruits wastes are abundant sources of bioactive compounds and nutrients, which are considered to be health beneficial. The main purpose was to characterise juice, pulp, peel and seeds of Piel de Sapo melon, in terms of several physicochemical characteristics (soluble solids content, titratable acidity, pH, potassium, colour and water activity), some bioactive compounds (total phenolics, vitamin C, chlorophylls and total carotenoids) and total antioxidant activity. Juice, pulp, peel and seeds represent 47, 19, 27 and 5% of melon total weight, respectively. Peel and seeds stood out by their higher concentration of total phenolics compounds and antioxidant activity when compared to edible parts. The highest potassium concentration was found in seeds. Chlorophylls were only detected in peel, while carotenoids were not detected in any part of the melon analysed. Juice and pulp contributed to 69% of vitamin C amount of the whole fruit. However, its concentration in peel was equivalent to the ones observed in juice and pulp. These results pointed out the importance of fruit wastes valorisation and the development of strategies for their re-utilisation.
- Innovating Portuguese Traditional Pastry – on the use of pasteurized egg yolk in “ovos moles”Publication . Fundo, Joana F.; Quintas, Mafalda A.; Brandão, Teresa R. S.; Silva, Cristina L. M.
- Development of a safer formulation of egg yolk cream: physicochemical and sensorial characteristics assessmentPublication . Fundo, Joana F.; Quintas, Mafalda A. C.; Brandão, Teresa R. S.; Silva, Cristina L. M.Egg yolk cream is a sweet confectioned with egg yolk, sugar and water. The use of raw egg products is a potential safety hazard in its production. In this work, a safer formulation is developed by using an easier to manipulate raw material – pasteurized liquid egg. Because of previous heat treatment, pasteurized liquid egg presents different sensorial, nutritional and physical properties. These changes may alter the final product's characteristics. In this work, a study on adding pasteurized egg white (as bulking agent) to the pasteurized liquid yolk was carried out. Samples made with shell eggs and with pasteurized liquid eggs were compared in terms of physical and chemical parameters. Results allowed characterizing the properties of typical egg cream and of alternative formulations using pasteurized egg yolk and white. A new formula of egg cream was developed and its sensorial acceptance was tested against the typical formulation.
- Effect of non-thermal methods on the safety of strawberries (Fragaria anannassa) and watercress (Nasturtium officinale)Publication . Alexandre, Elisabete M. C.; Santos, Dora M.; Fundo, Joana; Brandão, Teresa R. S.; Silva, Cristina L. M.
- The effect of polymer/plasticiser ratio in film forming solutions on the properties of chitosan filmsPublication . Fundo, Joana; Galvis-Sanchez, Andrea C.; Delgadillo, Ivonne; Silva, Cristina L. M.; Quintas, Mafalda A. C.In this work physical-chemical properties of chitosan/ glycerol film forming solutions (FFS) and the resulting films were analysed. Solutions were prepared using different concentrations of plasticising agent (glycerol) and chitosan. Films were produced by solvent casting and equilibrated in a controlled atmosphere. FFS water activity and rheological behaviour were determined. Films water content, solubility, water vapour and oxygen permeabilities, thickness, and mechanical and thermal properties were determined. Fourier transform infrared (FTIR) spectroscopy was also used to study the chitosan/glycerol interactions. Results demonstrate that FFS chitosan concentration influenced solutions consistency coefficient and this was related with differences in films water retention and structure. Plasticiser addition led to an increase in films moisture content, solubility and water vapour permeability, water affinity and structural changes. Films thermo-mechanical properties are significantly affected by both chitosan and glycerol addition. FTIR experiments confirm these results.
- Impact of ozone processing on microbiological, physicochemical, and bioactive characteristics of refrigerated stored Cantaloupe melon juicePublication . Sroy, Sengly; Fundo, Joana F.; Miller, Fátima A.; Brandão, Teresa R. S.; Silva, Cristina L. M.The objective of this study was to evaluate the impact of ozone treatment on microbiological decontamination (intrinsic microflora and inoculated Listeria innocua) and some physicochemical characteristics and bioactive compounds of Cantaloupe melon juice, also during refrigerated storage. To determine adequate ozone exposure, the survival curve of L. innocua was previously assessed. A thermal treatment was also performed seeking comparison with ozone treatment impact. After ozone exposure, L. innocua was not detected in juice samples, while thermal pasteurization allowed a reduction of 5.2 ± 0.2 log cycles. Although ozone reduced the intrinsic microflora loads, this reduction was higher for heat‐treated samples. Vitamin C was highly retained in ozone‐treated juices (68%), when compared with the pasteurized ones (39%). After 13 days of storage, ozone allowed the retention of the most quality parameters analyzed and, therefore, it can be considered as a promising alternative to traditional pasteurization of Cantaloupe melon juice. Practical applications The actual consumers' demand for high‐quality food standards has launched research to alternative and milder nonthermal processes, which have gained increasing attention and importance in the fruit juice industries. Ideally, preservation and/or processing of foods should involve technologies that prevent undesirable microbial survival and minimize quality attributes changes and nutrient losses. Thermal treatments are conventionally used to attain such targets; however, the content and the biological activity of the most health‐related compounds are dramatically reduced. In this context, and particularly in the beverages industries, ozone has been exploited due to its potential for inactivating spoilage and pathogenic microorganisms, while being effective in overall quality retention of the products.
- Effect of ozone on the quality of fresh-cut green beans (Phaseolus vulgaris L.) and bell peppers (Capsicum annuum L.)Publication . Alexandre, Elisabete M. C.; Fundo, Joana; Santos, Dora M.; Brandão, Teresa R. S.; Silva, Cristina L. M.Ozone is a potent oxidant and disinfectant agent with multiple industrial applications. The efficacy of ozone treatments has been recognised in the sanitation of equipments and water disinfections. Recently, ozone started to be used as an innovative food processing technology that guarantees product safety. The objective of this work was to study the effect of ozone on the quality of fresh-cut green beans (Phaseolus vulgaris, L.) and green and red bell peppers (Capsicum annuum, L.). The quality factors analysed were enzyme (peroxidase) activity, colour and texture for green beans, and colour, texture and pH for bell peppers. Experiments were carried out in pilot equipment. An ozone generator was interconnected to a container filled with tap water. Ozone was continuously incorporated in water and its content was indirectly measured by potential difference. Green beans and bell peppers were cut in small portions. Samples were immersed in ozonated and non-ozonated water baths and removed after different times till a maximum of 180 minutes. Data from both treatments were compared by analysis of variance. For green beans, results showed that ozone treatment did not affect the colour, but significantly influenced texture (firmness) and peroxidase inactivation (at 7% significance level). After 40 minutes enzyme activity was reduced approximately 20%. This inactivation was verified for the rest of the sampling times. Ozone treatment affected pH and texture (fracturability) of red bell peppers (at 1% significance level). The other quality factors were not significantly influenced by ozone.
- Effect of ultrasonication, thermosonication and UV-C irradiation on the quality of strawberries (fragaria anannassa) and red bell peppers (capsicum annuum L.)Publication . Santos Pedro, Dora M.; Alexandre, Elisabete M. C.; Fundo, Joana F.; Brandão, Teresa R. S.; Silva, Cristina L. M.
- UV-C radiation as an effective non-thermal process for ‘Cantaloupe’ melon juice decontaminationPublication . Mandro, Gabriela; Fundo, Joana F.; Miller, Fátima A.; Tremarin, Andréia; Brandão, Teresa R. S.; Silva, Cristina L. M.Thermal pasteurization has negative impacts on overall quality characteristics of foods. UV-C radiation has a germicidal effect and has been applied to eliminate undesirable microorganisms in food products. This technology is more effective in liquid foods, being an alternative non-thermal processing that can be applied to fruit juices.The objective of this study was to evaluate the effect of UV-C radiation on some quality characteristics and microbiological decontamination of cantaloupe melon (Cucumis meloL. var. reticulatus) juice, whichis an excellent source of antioxidant compounds, such as vitamins, phenolics and carotenoids. Cantaloupe melon juice was artificially inoculated with Alicyclobacillus acidoterrestrisspores (spoiler indicator) and Listeria innocua(non-pathogenic surrogate of L.monocytogenes), used as indicators of the UV-C treatment efficacy. The initial concentration of both microorganisms was around 107CFU/mL. Juice was exposed to UV-C radiation at an intensity of 13.44 W/m2, during 5 and 20 minutes. Some physic-chemical characteristics (pH, colour and soluble solids content), total phenolics and antioxidant capacity were evaluated before and after treatments. Exposure time affected significantly colour (very distinct alterations) and pH (slight increase from 6.3±0.1 in fresh, to 6.7±0.1 and 7.0±0.1 after 5 and 20 min of radiation; values are mean±margin of confidence interval at 95%). The remaining characteristics were not affected by the radiation and were similar to the ones observed in fresh/untreated juice. In terms of A. Acidoterrestris spores, reductions of 0.8±0.1 and 4.7±0.1log-cycles were observed after 5 and 20 minutes of radiation, respectively. For L. innocua, a reduction of 3.9±0.7 log-cycles was attained after 5 minutes and, for the highest exposure time, no cells were detected. Since UV-C was effective on microbial inactivation and was able to retain the most of quality parameters analysed, this technology can be considered as a promising alternative to traditional pasteurization of fruit juices.