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Accurate estimation of mineralizable nitrogen (N) from soil organic matter is essential to improve fertilizer management in agricultural systems. Mineralizable N refers to the amount of N in soil that is released during a certain period (ranging from 1 week to the length of a growing season). It has been estimated from increases in inorganic N during incubation or from N uptake by plants grown in a greenhouse or field. Many chemical soil tests measuring extractable organic N (EON) fractions have been proposed to predict mineralizable N. We evaluated the predictive value of these soil tests, using 2068 observations from 218 papers. Meta-analysis was used to find the best soil test, to analyse differences between field and laboratory experiments, and to determine whether their predictive value is affected by extraction intensity (% of total soil N that is extracted). The concentration of EON was positively related to mineralizable N, explaining on average 47% of the variation. It did not, however, explain more of the variation than total N. Best predictions (57% < R < 74%) were obtained when EON was extracted with hot CaCl, acid KMnO, acid KCrO, hot water or hot KCl. Extraction intensity was not related to the strength of the above-mentioned relationship. Predictions of mineralizable N were significantly worse when mineralization was measured in the field compared with measurements under controlled conditions. We found no evidence of a causal and direct relationship between EON and mineralizable N. Accuracy of soil testing may improve when the current 'single soil test approach' changes to a more complex approach, which includes different soil tests, soil properties and environmental conditions. [ABSTRACT FROM AUTHOR]

BSTRACT: A 1-y storage trial was designed involving different temperatures (8, 21, and 30 °C) to assess the antioxidant properties of a dessert formulated with concentrated juices of grape, blackberry, blackcurrant, raspberry, and cherry. The total antioxidant activity (TAA) of the dessert was measured as the scavenging capacity of the 2,2′-azino-di-[3-ethylbenzothiazoline-6-sulphonate] radical cation (ABTS) and as its iron-reducing ability (FRAP). Color was spectrophotometrically measured, and vitamin C and phenolics were analyzed by HPLC. The color parameters and the concentrations of different antioxidant compounds were affected by storage conditions, especially in samples stored at 30 °C, although the TAA remained practically invariable during storage. [ABSTRACT FROM AUTHOR]

This study was conducted to determinate the effect of industrial processing on the carbohydrates composition and in vitro starch digestibility in 4 varieties of infant cereals, 2 gluten-free (Growth, and Rice and carrots) and 2 with gluten (Mixed cereals, and Wheat). Samples were obtained at 4 processing stages (raw, roasted, film and commercial product) and total starch (TS), free glucose (FG), dextrin, amylose, and total dietary fiber (TDF) contents were evaluated. Industrial processing caused a significant decreased in TS and amylose and a significant increase in dextrin. Infant cereals showed a higher in vitro starch digestibility index than white bread (used as a reference), being fully hydrolyzed in-between 60 to 90 min of assay. It can be concluded that regarding the source of cereal used for the manufacture, the enzymatic processing ensure a complete digestion of starch and so the glucose availability for infant nutrition, while TDF may influence colonic events without affecting glucose absorption. [ABSTRACT FROM AUTHOR]

Compares the non-starch polysaccharides (NSP) and in vitro starch digestibility of raw and cooked chick peas. Sample preparation; Determination of NSP; Fraction of starch; Percentage of amylose; Impact of treatments; Rate and extent of digestion; Conditions for cooking.

Changes in the mineral content of peas (Pisum sativum, L.) as a function of size during commercial processing were studied. Peas were divided into four levels of maturity, and samples were taken on different sizes of peas at various stages of the canning process. Mineral content was determined by atomic absorption spectrophotometty. Significant changes were found in the content of copper, iron, magnesium and zinc during commercial canning, but these were dependent on pea size only in the case of copper, iron and zinc. Highest total losses for copper and zinc were obtained in immature stages while iron losses were highest at mature stages. [ABSTRACT FROM AUTHOR]

Examines the retention of selected minerals of four maturity levels of cowpea when pressure heated in a minimum amount of water. Relationship between maturity and mineral contents of cowpea; Moisture and mineral determinations; Effect of pressure heating on minerals of cowpeas.