A Fast GC-MS-Based Method for Efficacy Assessment of Natural Anti-Oxidants for Inhibiting Lipid Oxidation.

BACKGROUND: For health reasons it is preferred to prepare food products with edible fats and oils that are high in unsaturated fatty acids. Unfortunately, these unsaturated acids are susceptible to lipid oxidation and the addition of natural antioxidants, e.g., rosemary extracts, etc. is needed. OBJECTIVE: To assess the efficacy of natural oxidation inhibition strategies, fast, yet realistic, and objective methods are needed to study oxidation inhibition. METHODS: A model system consisting of salt and sunflower oil is proposed as a model for dry soups and sauces. Hexanal formation is studied using fast GC-MS as a quantitative indicator for lipid oxidation. RESULTS: A fast GC-MS method using a short, 6-m 150 µm inner-diameter column was developed that allowed elution of hexanal within approximately 20 s, with a total run time of 2 min. The GC method has quantification limits below 1 ppm and is hence much more sensitive than the human nose. CONCLUSIONS: The new accelerated method with hexanal read-out was successfully applied in a study to identify spices and herbs mixtures that can act as natural inhibitors of lipid oxidation. The fast GC-MS method is extremely stable and allowed the analysis of thousands of samples with very little maintenance. HIGHLIGHTS: With the right mixture of spices and herbs, lipid oxidation can be delayed more than 100 times as compared to non-stabilized systems.

Nutritional Quality of Dry Vegetable Soups.

Dry soups with vegetables are often perceived as having low nutritional quality, but there are only limited data on the nutritional value of dry soups. Therefore, we measured the nutritional composition of dry vegetable powders used in dry soups and compared the results with published data on fresh and cooked vegetables. We also analyzed the nutritional composition of dry vegetable soups and compared these with published data on home-made and other soups. Dietary fiber, minerals, vitamins, and carotenoids in dry vegetables powders and soups were analyzed. Based on these data, a nutrient density score was calculated as measure of overall nutritional quality. Nutrient density scores for fresh and cooked vegetables, as well as home-made and other soups, were calculated based on the United Stated Department of Agriculture (USDA) and "Bundeslebensmittelschlüssel" (BLS) food composition data. The nutrient density scores of dry vegetable powders did not systematically differ from cooked vegetables. Nutrient contributions to European Food and Safety Authority (EFSA) dietary reference intakes per 250 mL serving of soup ranged from 11-45% for fiber; 3-23% for iron, magnesium, and zinc; 8-22% for potassium; 11-15% for vitamin A; 2-17% for B-vitamins; and 2-15% for vitamin K. The nutrient density scores of dry vegetable soups were in the same order of those of home-made and other soups. These data indicate that dry vegetable soups, like home-made soups, can deliver a significant part of recommended daily nutrient and vegetable intake.