Valorisation of Cantaloupe melon peel by freeze drying process

Melon is a fruit with a high amount of waste parts, particularly peel (around 25 % of total weight). Wastes are abundant sources of bioactive compounds, considered to be health beneficial. Waste parts deserve valorisation that may be attained by developing strategies to transform them into more convenient forms that can be used as food ingredients.The objective was to transform melon peel into powder by freeze drying and assess the impact of the process on some quality characteristics (total phenolics and chlorophylls contents and antioxidant activity) and on total mesophylls and yeasts and moulds flora. Cantaloupe melon (Cucumis meloL. var. reticulatus) peel was removed and cut into small pieces. Approximately 300 g of peel was submitted to a freeze drying process (-45 ºC, 20 Pa, 96h), replicated twice. Dried samples were smashed into powder and analysed.The characteristics above mentioned and target microorganisms were evaluated before and after the freeze drying process. Initial moisture was 9.0 (dry basis; d.b.) and the water activity of dried samples was 0.060±0.010.Total phenolics content (μggallicacid/gsampled.b.) was significantly affected by the freeze drying process, decreasing 22% (2216.0±312.9 in fresh and 1720.7±227.4 after drying). Total chlorophylls content (μg/g d.b.) suffered a significant decay of 7% (923.4±13.4 in fresh and 859.2±24.1in dried samples). Antioxidant activity (μgascorbic acid/gsampled.b.) was not affected (2079.2±305.4 in fresh and 1595.6±727.4 after drying).Initial counts of mesophylls were 8.0x106cfu/mL, decreasing 0.3±0.1 log-cycles after freeze drying. Yeasts and moulds averaged 3.7x105cfu/mL in fresh peel, suffering a fall of 1.1±0.1 log-cycles after processing.Freeze dried melon peel retained antioxidant activity and a considerable amount of total chlorophylls and can be used as an innovative food ingredient with bioactive compounds. Investigation on decontamination processes is still required for maximum quality retention and safety levels of the material.info:eu-repo/semantics/publishedVersio

Impact of ozone processing on microbiological, physicochemical, and bioactive characteristics of refrigerated stored Cantaloupe melon juice

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.info:eu-repo/semantics/publishedVersio

Thermal and non-thermal Cantaloupe melon juice pasteurization: Assessment of the impact of ozone exposure on microbiological, physicochemical and bioactive characteristics

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Importance of freshwater fish in Tonle Sap Lake for food and nutrition in Cambodia

Le lac Tonle Sap est un écosystème unique qui abrite une grande diversité de poissons d'eau douce. L'insécurité alimentaire et les carences en micronutriments sont toujours présentes au Cambodge. Les poissons d'eau douce sont consommés quotidiennement par les populations des villages flottants et leur contribution aux besoins humains à l'état frais ou transformé n'est pas clairement connu. Au cours des dernières décennies, les stocks et la diversité des poissons ont considérablement diminué pour des raisons ce qui constitue une menace pour la sécurité alimentaire et la nutrition. L'objectif de cette thèse était d'évaluer dans quelle mesure les espèces de poissons disponibles dans le lac pouvaient être intéressantes pour la nutrition des populations locales et si le processus de séchage était une bonne option pour produire un ingrédient d'intérêt nutritionnel pour les personnes vulnérables en dehors des périodes légales de pêche.Notre stratégie de recherche s'est articulée en quatre phases. Une enquête sur la consommation et la perception des espèces de poissons a été menée auprès des populations vivant dans les villages flottants. Les dix espèces de poissons les plus consommées par ces populations ont été identifiées et la consommation caractérisée. Le profil nutritionnel et les teneurs en métaux lourds des poissons ont été déterminés et utilisés pour identifier les espèces les plus nutritives et saines en utilisant les indicateurs SAIN et LIM. Les dix espèces de poissons sont riches en oméga 3 et les teneurs en vitamine A, Fe et Zn sont plus élevées dans les petits poissons consommés entiers. Les teneurs en Mn, As et Pb étaient supérieures aux limites maximales autorisées et, de ce fait, sept espèces de poissons appartiennent aux groupes alimentaires à consommer en petites quantités. L'espèce de poisson la plus intéressante était Henicorhynchus siamensis pour sa composition nutritionnelle équilibrée (protéines, lipides, minéraux totaux), ses niveaux élevés d'AGPI n-3 (DHA, EPA) et de micronutriments essentiels (Fe, Zn, vitamine A), et ses faibles niveaux de métaux lourds.Henicorhynchus siamensis a été séché à quatre températures (50 °C, 60 °C, 70 °C et 80 °C) et les cinétiques de dégradation de la vitamine A et des acides gras ont été suivies. La poudre de poisson a une faible activité de l'eau (0,65) et, si le procédé est bien mené, elle peut être riche en protéines, lipides et minéraux. En revanche, les lipides polyinsaturés et la vitamine A sont partiellement dégradés et le manganèse est concentré. Les problèmes de qualité du poisson sont à surveiller car ils peuvent refléter la santé de l'écosystème et conduire à l'intoxication ou même à l'empoisonnement des consommateurs. L'intérêt des poudres de poisson pour les programmes de nutrition et santé dans les pays en développement est discuté.The Tonle Sap Lake is a unique ecosystem that supports a wide variety of freshwater fish. Food insecurity and micronutrient deficiencies are still present in Cambodia. Freshwater fish are consumed daily by people in floating villages and their contribution to human needs in fresh or processed form is not clearly known. In recent decades, fish stocks and diversity have declined considerably for reasons that pose a threat to food security and nutrition. The objective of this thesis was to assess the extent to which the fish species available in the lake could be of nutritional interest to local populations and whether the drying process was a good option for producing an ingredient of nutritional interest to vulnerable people outside of legal fishing periods.Our research strategy was articulated in four phases. A survey on the consumption and perception of fish species was carried out among people living in the floating villages. The ten species of fish most consumed by these populations were identified and their consumption characterised. The nutritional profile and heavy metal content of the fish were determined and used to identify the most nutritious and healthy species using the SAIN and LIM indicators. All ten fish species are rich in omega-3 and the levels of vitamin A, Fe and Zn are higher in small fish consumed whole. The contents of Mn, As and Pb were above the maximum permitted limits and therefore seven fish species belong to the food groups to be consumed in small quantities. The most interesting fish species was Henicorhynchus siamensis for its balanced nutritional composition (protein, lipids, total minerals), high levels of n-3 PUFAs (DHA, EPA) and essential micronutrients (Fe, Zn, vitamin A), and low levels of heavy metals.Henicorhynchus siamensis was dried at four temperatures (50°C, 60°C, 70°C, and 80°C) and the degradation kinetics of vitamin A and fatty acids were followed. The fish powder has a low water activity (0.65) and, if the process is conducted properly, it can be rich in protein, lipids and minerals. However, polyunsaturated lipids and vitamin A are partially degraded and manganese is concentrated. Fish quality problems are to be monitored as they can reflect the health of the ecosystem and lead to poisoning of consumers. The relevance of fish powders for nutrition and health programs in developing countries is discussed

Freeze-drying processes applied to melon rinds to attain a value-added food ingredient

Aim: Several studies pointed out melon rinds as rich sources of bioactive compounds with relevant antioxidant activity. Being considered a non-edible part with no economic value, fruit industries discharge large amounts of these residues to the environment. If these wastes are conveniently processed and transformed, novel food ingredients with potential health benefits may arise.The objective was to transform melon rinds by freeze-drying to attain dried small bits that can be used as additives to enrich diverse food matrixes. An ozone pre-treatment was applied seeking decontamination and retention of quality characteristics. The impact of these processes was assessed in bioactive compounds (vitamin C, total phenolics and chlorophylls), antioxidant activity, and melon peel microflora (mesophylls, yeasts and moulds) during 7 weeks of storage of the dried materials at room temperature. Method: Melon rinds (Cucumis melo L. var. reticulatus) were cut in small cubes. Before freeze-drying (-50 °C, 1.5-2 bar, 80-90 h) and storage (7 weeks in the dark at room temperature), part of the samples was exposed to a gaseous ozone pre-treatment (15 °C, 152±71 ppm, 30 min). Vitamin C, total phenolics, chlorophylls and antioxidant activity were analysed by HPLC and spectrophotometric methods in raw peel and throughout storage. Mesophylls, yeasts and moulds were also enumerated. Results: Vitamin C, total phenolics, chlorophylls, and antioxidant activity decreased during storage in both non-ozonized and ozonized dried samples. However, pre-ozonized samples retained better the bioactive compounds analyzed throughout the storage: almost 85% of total phenolics and chlorophylls were preserved, and 66% of vitamin C. In terms of microflora inactivation, the effects of ozone and freeze-drying were not significant. However, a decrease of ~1 log-cycle was observed at the end of storage for the groups of microorganisms considered. Studies with undesirable target microorganisms are required to attain a safe product. Conclusion: Freeze-drying with an ozone pre-treatment can be considered a potential process to transform melon peel into an edible form. When the small cubes of melon rinds were freeze-dried, they became lighter and softer. They can be incorporated into different products (e.g., cakes, breads, yogurts), enriching their nutritional profile and creating a value-added food ingredient.info:eu-repo/semantics/publishedVersio

Use of an experimental design to optimise the saponification reaction and the quantification of vitamins A 1 and A 2 in whole fish

International audienceIn ASEAN countries, small freshwater fish species contribute to the nutritional needs of people with few livelihoods by providing them with significant amounts of protein, fat, vitamins and minerals. Some species are eaten whole (with their organs, skin, bones, head and eyes). To estimate the vitamin A content of these foods, conventional saponification has been applied but has not been able to fully release the retinol. Our objective was to optimise the conditions of vitamin A saponification in whole fish to have a reliable estimate of their contribution to intakes. The effects of temperature and saponification time on the retinol quantification of whole fish were evaluated using a two-factor experimental design. Reaction time had a significant effect on the saponification of standard retinyl palmitate and whole fish (p≤0.05). For whole fish, the best conditions for the saponification were to heat the samples to 80 °C for 43 minutes. Under these conditions, the retinol is well liberated from the matrix and protected from degradation and isomerisation reactions. The time-temperature couple used is more intense than that recommended for quantifying vitamin A in milk or enriched margarines. The protective effect of the food matrix against the release of retinol is evident. Vitamin A 2 alcohol (3,4-didehydroretinol) was detected in five species and the overall vitamin A contents ranged from 9.6 to 737.5 μg RE/100 g in species frequently consumed in Cambodia. The two species of small fish consumed whole were the ones that contained significantly more vitamin A among the ten tested (p≤0.05). Highlights: Vitamin A 2 alcohol was quantified in five fish species. The official saponification partially released retinol in whole fish. The optimised reaction required heating the sample to 80 °C for 43 min

Does drying preserve the nutritional quality of small freshwater fish without excessive concentrations of heavy metals?

The potential of drying to preserve the nutritional quality of a small freshwater fish Henicorhynchus siamensis was assessed. Drying time to reach moisture content and water activity of 10 g/100g and 0.65 ranged from 55 h at 50 °C to 20 h at 80 °C, respectively. Dried fish powder is rich in macronutrients (protein, lipid and ash) and essential minerals (calcium, phosphorus, iron and zinc) due to water removal and despite lipid loss. It is still rich in polyunsaturated fatty acids although docosahexaenoic acid was reduced except at 60°C. Vitamin A was rapidly degraded and manganese was concentrated at high level. However, mean score for the nutritional adequacy of the 15 nutrients (SAIN) and score of nutrients to limit (LIM) show that the fish powder can be used as a food ingredient for example in the formulation of fish snack or instant soup. With the abundance of Henicorhynchus siamensis, dried fish powder from this species could contribute to food security in Cambodia, especially vulnerable people in rural areas

Nutritional benefits and heavy metal contents of freshwater fish species from Tonle Sap Lake with SAIN and LIM nutritional score

International audienc

Valorization of Cantaloupe melon peel by freeze drying process

info:eu-repo/semantics/publishedVersio