The application of hydrostatic high pressure on an industrial line of nectarine (Prunus persica L.) purées was assessed in comparison with the traditional thermal treatment of pasteurization. Changes after thermal processing (85 °C, 5 min) and after high-pressure processing (HPP: 450 or 600 MPa for 5 or 10 min) and during the refrigerated storage (60 d) of an industrially produced nectarine purée were evaluated. Conventional heat pasteurization as well as HPP showed similar microorganisms' inactivation and maintained the microbial stability of purées until the end of the refrigerated storage (60 d). In general, thermally treated purée and HP-treated purée at 600 MPa showed more intense color changes after processing than the other treatment. In addition, thermally treated purée showed more intense color changes during storage than HPP. The highest carotenoids extractability was found in those purées treated at the lowest high-pressure-treatment intensity and holding time (450 MPa/5 min), but at the end of the storage (day 60), no differences in individual or total carotenoid levels were found between the purées. HPP at 600 MPa/10 min showed the highest polyphenols content after the treatment and during the storage. At day 0, significantly higher values were found of total antioxidant activity in purée HP-treated at 450 MPa/10 min than in untreated purée; while at the end of the storage, HP-treated purée at 600 MPa/10 min had the highest antioxidant activity. Hydrostatic high-pressure application in the industrial line of nectarine purée presented some advantages compared to the thermal treatment; however, some of the changes found were lessen during the storage period. In addition, more studies need to be carried out for HP-treatment intensity optimization.

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The volatile profile of a plum purée (cv. Crimson Globe) processed by high hydrostatic pressure was evaluated by the method of solid-phase micro-extraction gas chromatography/mass spectrometry (SPME-GC/MS). Two pressure intensity levels and three holding times were applied (400 and 600 MPa for 1, 150 and 300 seconds) in order to know the effect of processing on the original aroma of plum purée. High pressure processed purées were compared to raw purée (unprocessed purée). A total of 40 volatile compounds were identified in the headspace of the plum purée. The major compounds identified were an aldehyde (hexanal) and two alcohols (hexan-1-ol and (Z)-hex-3-en-1-ol). The first two compounds were not affected by processing while the levels of (Z)-hex-3-en-1-ol were reduced at the less intense pressure treatments. Among the total volatile compounds isolated (40), 17 were not modified by high pressure processing (HPP) since no significant differences were observed after processing. The rest of the compounds (23) were significantly influenced by HPP. The modifications of these 23 volatiles represented changes of the 1.8% of the total aroma of the original purée. Significant differences were noticed in several compounds after the applied treatments, although the overall effect on the profile would not be significant. Results showed that the most intense treatments did not significantly alter the original aroma of plum purée. Therefore, HPP appears to be an alternative technology for the preservation of aromatic compounds of plum purée.

High pressure processing (HPP) is an alternative to the traditional thermal treatment. The physicochemical composition, instrumental color and bioactive compounds (carotenoid and phenolic compounds) were evaluated in two pumpkin purées after processing (HPP: 400-600 MPa and thermal treatment) and after storage. One sample of purée was taken in the industry after the first sieve and before the thermal blanching, and the other was taken after deaeration and before pasteurization. HPP of pumpkin purée presented some advantages compared to the thermal treatment such as lower color modifications after processing and during storage, and higher nutritional value (some carotenoid and polyphenol contents were higher in HPP). The application of initial pretreatments reduces the original color intensity of the purées, and thus diminishes the differences of HPP and the thermal treatment in this aspect. However, the application of pretreatments is a necessary step for the stabilization of pumpkin purées during storage. PRACTICAL APPLICATIONSHydrostatic high pressure is a real alternative to thermal processing in determinate food products. Every year, new high pressure-processed products are in the market. However, only a few studies have evaluated the application of this technology in an industrial line of vegetable processing, which present some particularities (thermal pretreatments and additives are usually added). This paper presents valuable information for the application of high pressure processing at industrial level.

Organic horticulture is a sustainable agricultural model that can provide high quality products and allows conservation of genetic diversity. Traditional tomato varieties are well adapted to organic production and they have the organoleptic characteristics demanded by consumers. Seven traditional tomato varieties were studied: BGV-001020, BGV-000998, BGV-001000, BGV-004123, CIDA-44-A, CIDA-62, CIDA-59-A, and they were compared with a tomato Marmandetype commercial cv. 'Baghera', all them grown under organic production. Several quality variables were measured to establish whether any of the traditional varieties might be suitable for commercial production. CIDA-62 was shown to be the most promising variety. It produces tomatoes of very high quality under organic conditions. It excels in terms of bioactive compounds such as vitamin C (459.22 mg kg -1 fw) and lycopene (62.25 mg kg -1 fw) and in its total antioxidant activity (43.58 mg Trolox/100 g fw). It is also outstanding in terms of its sugar content (4.56% fructose and glucose combined) and of its total soluble solids content (6.22°Brix). All of these variables are associated with both sensory quality and health benefits. Other varieties that emerged with relatively high levels of total soluble solids content, lycopene, vitamin C and total antioxidant activity were BGV-004123 and BGV-001020.Additional key words: bioactive compounds; landrace; organic horticulture production; quality; Solanum lycopersicum. Resumen Caracterización de variedades tradicionales de tomate producidas en cultivo ecológicoLa horticultura ecológica es un modelo de agricultura sostenible que puede proporcionar productos de alta calidad y permite la conservación de la diversidad genética. Las variedades tradicionales de tomate están bien adaptadas a la producción ecológica, y presentan las características organolépticas demandadas por los consumidores. Siete variedades tradicionales de tomate han sido estudiadas: BGV-001020, BGV-000998, BGV-001000, BGV-004123, CIDA-44-A, CIDA-62, CIDA-59-A, y se han comparado con una variedad comercial tipo Marmande ('Baghera'), todas ellas producidas en condiciones de cultivo ecológico. Se han evaluado diversas variables de calidad con el fin de establecer si alguna de las variedades tradicionales podría ser seleccionada para su producción ecológica comercial. La variedad CIDA-62 se ha mostrado como la más interesante. Sobresale en compuestos bioactivos como son vitamina C (459,22 mg kg -1 pf) y licopeno (62,25 mg kg -1 pf), y su actividad antioxidante total (43,58 mg Trolox/100 g pf). También destaca por el contenido en azúcares (4,56% la suma de fructosa y glucosa) y sólidos solubles totales (6,22°Brix). Todas estas variables están relacionadas con la calidad organoléptica y los beneficios para la salud. Otras variedades que presentan buenas características, con alto contenido en sólidos solubles totales, licopeno, vitamina C y actividad antioxidante total son BGV-004123 y BGV-001020.