Effect of ultrasound pre-treatment on the physical, microbiological, and antioxidant properties of calçots

The effect of ultrasound (US) treatment (40 kHz, 250 W) for 0, 10,25 and 45 min on the physical and microbiological quality, total antioxidant capacity (TAC) and total phenolic content (TPC) of calçots (Allium cepaL.) was evaluated. Moreover, the effect of roasting (270 °C, 8 min) and in vitro simulated digestion on the antioxidant properties was studied. Overall, US treatment had no effect of the physical quality and antioxidant properties of calçots regardless the treatment time, while thermal processing produced an increase on the TAC and maintenance in TPC. Furthermore, the digestion process caused a remarkable decrease on the TAC and TPC, but that decrease was higher in roasted than in fresh samples. The microbial load of all US-treated fresh samples was below 6 log (cfu g−1) and a decrease of 1-log reduction was observed after treating for 45 min. Those results indicated that US pre-treatment had no negative effects on the quality of calçot while produced a decrease on the microbial load at high processing times.This work was supported by ACCIÓ (Generalitat of Catalonia, RD14-1-004), Sociedad Agrícola i Secció de Crèdit de Valls S.C.C.L., Cooperativa of Cambrils, and PGI ‘Calçot de Valls’. This work was also supported by the ‘Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement’ (FI-2017-B2-00164, L. Zudaire) and CERCA Programme of Generalitat de Catalunya. T. Lafarga is in receipt of a ‘Juan de la Cierva’ contract awarded by the Spanish Ministry of Economy, Industry, and Competitiveness (FJCI-2016-29541). I. Aguiló-Aguayo thanks the National Programme for the promotion of talent and its employability of the ‘Ministerio de Economía,Industria y Competitividad’ of the Spanish Government and to the European Social Fund for the Postdoctoral Senior Grant ‘Ramon y Cajal’ (RYC-2016-19949)

Steaming and sous-vide: Effects on antioxidant activity, vitamin C, and total phenolic content of Brassica vegetables

The present study evaluated the effect of thermal processing on the colour, antioxidant activity, vitamin C content, and total phenols of six Brassica vegetables. The landrace Grelo was the best source of total phenols (162.7 ± 3.5 mg/100 g; p<0.05). Cavolo Nero di Toscana, also known as “black cabbage”, showed the highest content of vitamin C, calculated as 290.6 mg/100 g (p<0.05). The concentration of total antioxidants, phenols, and vitamin C was significantly reduced after both steaming and sous-vide processing (p<0.05). Overall, no differences were oberved between both cooking strategies. However, for some of the studied vegetables, sous-vide processing resulted in higher losses when compared to steaming (p<0.05). Uncommon Brassica vegetables such as Grelo can be as nutritious and healthy as commonly consumed ones. However, the effect of cooking on the content of nutritious compounds should be considered when calculating their dietary intake from cooked crucifers.This work has been supported by the CERCA Programme of Generalitat de Catalunya. T. Lafarga is in receipt of a Juan de la Cierva contract awarded by the Spanish Ministry of Economy, Industry, and Competitiveness (FJCI-2016–29541). I. Aguiló-Aguayo thanks the National Programme for the Promotion of Talent and its Employability of the Spanish Ministry of Economy, Industry and Competitiveness and to the European Social Fund for the Postdoctoral Senior Grant Ramon y Cajal (RYC-2016-19949). Researchers also thank Silvia Villaró and Gisela Pérez for their technical support

Effect of pre-harvest conditions and postharvest storage time on the quality of whole and fresh-cut calçots (Allium cepa L.)

Pre-harvest conditions such as cultivar, cultivation site and planting time could affect the storability, quality and shelf-life of fruit and vegetables. The influence of onion cultivar, cultivation site and planting time on the storability and quality of whole fresh and roasted calçots (Allium cepa L.) was investigated. Moreover, the suitability for fresh-cut processing of four different calçots was studied. Samples from 'Montferri' onion cultivar presented the best storability. Overall, postharvest storage time had no remarkable effect on the quality of whole calçots but produced an increase on the antioxidant properties of all samples. In relation to the aptitude to minimal processing, 'Montferri' onion cultivar cultivated at Viladecans in August showed the best results in terms of quality throughout their postharvest storage time. Therefore, cultivar and postharvest storage time could have more effect than cultivation site and planting time on the quality of whole and fresh-cut calçots.This work was supported by ACCIÓ (Generalitat of Catalonia, RD14-1-004), Sociedad Agrícola I Secció de Crèdit de Valls S.C.C.L., Cooperativa of Cambrils, and PGI ‘Calçot de Valls’. This work was also supported by the ‘Secretaria d’Universitats I Recerca del Departament d’Economia I Coneixement’ (FI-2017-B2-00164, L. Zudaire) and CERCA Programme of Generalitat de Catalunya. I. Aguiló-Aguayo thanks to the National Programme for the Promotion of Talent and its Employability of the ‘Ministerio de Economía, Industria y Competitividad’ of the Spanish Government and to the European Social Fund for the Postdoctoral Senior Grant ‘Ramon y Cajal’ (RYC-2016-19949)

Effects of long-term controlled atmosphere storage, minimal processing, and packaging on quality attributes of calçots (Allium cepa L.)

Calçots are the immature floral stems of the second-year onion (Allium cepa L.) resprouts. Modified atmosphere packaging or vacuum packaging are suitable alternatives to preserve fresh-cut vegetables. The objective of this study was to evaluate the effect of postharvest storage time of raw vegetable stored under controlled atmosphere and used packaging system after minimal processing on the quality of fresh-cut calçots. Calçots used for minimal processing were stored under 1.0 kPa O2 + 2.0 kPa CO2 at 1 ℃ for 30 and 60 days. Fresh-cut calçots were packaged using passive modified atmosphere packaging or vacuum packaging and were stored at 4 ℃ for 15 days. Calçots stored under controlled atmosphere for 30 days presented better retention of quality and in turn, being more suitable for minimally processing. Vacuum packaging preserved the physicochemical quality of fresh-cut calçots better after 15 days. Mesophilic aerobic counts were also higher in fresh-cut calçots stored under modified atmosphere packaging, but all counts were below the recommended limits during and at the end of their shelf-life (15 days). The most suitable conservation strategy might be to store whole calçots under controlled atmosphere for 30 days and after minimally processing, packaged under vacuum in order to extend the shelf-life of fresh-cut calçots.The author(s) disclosed receipt of the following financial support for the research, authorship, and/ or publication of this article: This work was supported by ACCIÓ (Generalitat of Catalonia, RD14-1-004), Sociedad Agrícola i Secció de Crèdit de Valls S.C.C.L., Cooperativa of Cambrils and PGI “Calçot de Valls”; AGAUR (2015-FI-B-00284); and CERCA Programme of Generalitat de Catalunya. Ingrid Aguiló-Aguayo thanks the “Ministerio de Economía, Industria y Competitividad” of the Spanish Government for the Postdoctoral Senior Grant “Ramon y Cajal” (RYC-2016-19949) and T. Lafarga for the Juan de la Cierva contract (FJCI-2016-29541)

Evaluación de diferentes estrategias químicas, físicas y biológicas para el desarrollo de productos vegetales de calidad enteros o mínimamente procesados

L’increment en la demanda de productes saludables i fàcils de consumir ha provocat un creixement de la producció i el disseny de nous productes mínimament processats (MP) basats en fruites i/o hortalisses. L'objectiu principal de la present tesi va ser estudiar l'efecte de diferents estratègies químiques, físiques i biològiques sobre la qualitat de dues matrius vegetals (pera i calçot) senceres i MP. Els tractaments aplicats en postcollita juntament amb els tractaments aplicats durant el processat mínim i conservació, van permetre obtenir dos productes d'IV gamma de gran qualitat amb una alta vida útil en refrigeració (4 ° C). Finalment, al llarg de la tesi es va avaluar l'efecte de la digestió in vitro simulada sobre les propietats antioxidants. Els resultats obtinguts van demostrar que la bioaccesibilitat del contingut total de fenols en la fase intestinal en peres i calçots va ser del 5-20% i 50%, respectivament.El incremento en la demanda de productos saludables y fáciles de consumir, ha hecho que crezca la producción y el diseño de nuevos productos mínimamente procesados (MP) basados en frutas y/o hortalizas. El objetivo principal de la presente tesis fue el estudio del efecto de diferentes estrategias químicas, físicas y biológicas sobre la calidad de dos matrices vegetales (pera y calçot) enteras y MP. Los tratamientos aplicados en poscosecha junto con los tratamientos aplicados durante el procesado mínimo y conservación, permitieron obtener dos productos de IV gama de gran calidad con una alta vida útil en refrigeración (4 °C). Por último, a lo largo de la tesis se evaluó el efecto de la digestión in vitro simulada sobre las propiedades antioxidantes. Los resultados obtenidos demostraron que la bioaccesibilidad del contenido total de fenoles en la fase intestinal en peras y calçots fue del 5-20 % y 50 %, respectivamente.The increase in the demand for healthy and ready-to-eat products has led to the production and design of new minimally processed products based on fruits and/or vegetables. The main objective of the thesis was to study the effect of different chemical, physical and biological strategies on the quality of two whole and fresh-cut vegetable matrices (pear and calçot). The treatments applied in postharvest with the treatments applied during the minimal processing and conservation, led to a two high quality fresh-cut products with long shelf-life under refrigeration storage (4 ° C). Finally, throughout the thesis the effect of in vitro simulated digestion on the antioxidant properties was studied. The obtained results demonstrated that bioaccessibility of total phenolic content of pears and calçots was around 5-20 % and 50 % at the end of the intestinal phase, respectively