Changes in quality of low-moisture conditioned pine nut (Pinus gerardiana) under near freezing temperature storage

Abstract

Changes in quality of low-moisture conditioned pine nut (Pinus gerardiana) under near freezing temperature storage Cambios en la calidad del piñ ón en condiciones de baja humedad (Pinus gerardiana) al almacenarlo a temperaturas cercanas al punto de congelación Changes in quality of low-moisture conditioned pine nuts (Pinus gerardiana) under near freezing temperature storage were investigated. Nuts were adjusted to different moisture content (17.3% + 0.42, 15.1% + 0.26, and 13.3% + 0.24) with 358C, 20%RH, sealed in air-tight jars and stored at 73 and 718C for 12 months. In general, free fatty acid content and peroxide value of the nuts increased, while sensory quality decreased during the storage. Low-moisture nuts had lower respiration, free fatty acid content, and peroxide value. Nuts stored at 738C had less visible mold infection and browning percentage than at 718C. Lowmoisture treatment exerted a slight negative effect on texture, but had significant preservative effects on color, odor, and taste during storage. Overall, integration of low-moisture conditioning and near freezing temperature storage can be a promising non-chemical way for maintaining the postharvest quality and extending shelf-life of pine nuts.Keywords: pine nut; low-moisture conditioning; freezing temperature; quality; shelf-life Se investigaron los cambios en la calidad de pin˜ones en condiciones de baja humedad (Pinus gerardiana), almacenados a temperaturas cercanas al punto de congelamiento. É stos fueron tratados con un contenido de humedad diferente (17,3% + 0,42, 15,1% + 0,26 y 13,3% + 0,24), con 358 C, 20% HR, sellados en frascos a prueba de aire y almacenados a 73 y 718 C durante 12 meses. En general, se constato´que, durante el almacenamiento, aumento´el contenido de su a´cido graso libre ası´como su valor de pero´xido, disminuyendo su calidad sensorial. Los pin˜ones almacenados con ma´s bajo nivel de humedad presentaron niveles de respiracio´n, a´cido graso libre y valor de pero´xido ma´s reducidos, en tanto que aquellos que se almacenaron a 738 C mostraron niveles de infeccio´n de moho visible y porcentajes de oscurecimiento menores que los almacenados a 718 C. El tratamiento para bajar la humedad tuvo un efecto negativo menor en la textura y surtio´efectos conservantes significativos en el color, el olor y el sabor durante el almacenamiento. En general, la integracio´n del tratamiento de baja humedad con el almacenamiento a temperaturas cercanas al punto de congelamiento puede ser un me´todo no quı´mico prometedor para preservar la calidad postcosecha y extender el periodo de conservacio´n de pin˜ones.Palabras clave: pin˜o´n; tratamiento de baja humedad; temperatura cercana al congelamiento; calidad; periodo de conservacio´n

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“…The degree of lipid oxidation in brown rice increased with prolonged storage, which leads to increase in CV. Fluctuations in CV of brown rice stored at 25°C may be attributed to instability of lipoxygenase during storage (Cai et al, 2013). The decomposition of carbonyl compounds during prolonged storage at high temperatures decreased CV in brown rice at 35°C after 225 day of storage.…”

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“…Since Se functions as an antioxidant and can form selenoproteins with antioxidant activity, the element seems to exert a positive effect on preventing Se-GBR oxidation during storage. Cai, Liu, and Ying (2013) proposed that POV is strongly linearly correlated with storage temperature and that lower temperatures are beneficial to freshness, oxidation retardation, and maintenance of low oxidative indices in samples. …”

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