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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.
- 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.
- 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 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.
- Effect of non-thermal processing on the aromatic profile of Cantaloupe melon juicePublication . Georgiev, Radoslav; Pereira, Joel; Fundo, Joana F.; Miller, Fátima A.; Brandao, Teresa R.S.; Chalova, Vesela I.; Silva, Cristina L. M.
- Quality changes in fresh-cut ‘Rocha’ pear as affected by oxygen levels in modified atmosphere packaging and the pH of antibrowning additivePublication . Gomes, M. Helena; Fundo, Joana F.; Poças, M. Fátima; Almeida, Domingos P. F.Respiratory behavior of fresh-cut ‘Rocha’ pear suggests that optimization of O2 concentration inside modified atmosphere packages (MAP) is of limited benefit. To test this hypothesis, packages were designed to achieve three equilibrium O2 partial pressures. Fresh-cut ‘Rocha’ pear was treated with 250 mM calcium ascorbate solutions buffered at pH 3.0 and pH 7.0, packaged under the three MAP conditions, and stored at 5 ◦C for 20 d. Actual O2 levels (mean ± confidence interval at 95%) during the experiment were 16.7 ± 0.2, 1.8 ± 0.2 and 0.25 ± 0.04 kPa with corresponding CO2 levels of 1.3 ± 0.1, 4.3 ± 0.2 and 6.5 ± 0.4 kPa. Changes in quality attributes related to fruit metabolism, namely firmness, titratable acidity, pH, and soluble solids content were not affected by O2 levels. Overall changes in water activity, levels of ascorbate, and microbial growth were also independent of O2 levels. Oxygen partial pressure inside the packages affected browning, which was more intense at 16.7 kPa O2. Sensory analyses performed after 8 d in storage confirmed that panelists perceived the differences in color but did not detect differences in firmness or taste among the samples under different O2 levels. Browning was more intense at pH 3.0 than at pH 7.0 but the kinetics of other quality attributes were not affected by pH. No significant improvements of quality attributes dependent on the physiology of respiration of fresh-cut ‘Rocha’ pear can be obtained by reducing O2 partial pressure inside the packages.
- Thermosonication applied to kiwi juice processing: anti-listerial effect and quality retentionPublication . Striglio, Federica M.; Fundo, Joana F.; Miller, Fátima A.; Brandão, Teresa R.S.; Silva, Cristina L.M.
- Influence of ozone pre-treatment on the quality of frozen strawberries (Fragaria ananassa D.)Publication . Alexandre, Elisabete M. C.; Fundo, Joana F.; Santos Pedro, Dora M.; Brandão, Teresa R. S.; Silva, Cristina L. M.