Yellow-coated quinoa (Chenopodium quinoa Willd) - physicochemical, nutritional, and antioxidant properties.

BACKGROUND: Quinoa seeds are an excellent source of nutrients and phytochemical compounds with well documented activity; however, different cultivars are usually characterized by different physical properties and chemical composition. This study presented the physical properties, nutrient content, and antioxidant capacities of 25 cultivars of yellow-coated quinoa. RESULTS: The results demonstrated that quinoa seeds may be an excellent source of dietary fiber (up to 198 g kg-1 d.m. - Baer cultivar), with a 1:2 ratio of the soluble to insoluble fraction. Digestible carbohydrates were present at the highest level in the Puno cultivar (640 g kg-1 ). The highest content of proteins was determined in the Colorado 407D and Faro cultivars (c.a. 16%). The average content of albumin and globulins in the seeds was 29.2 and 65.6 g kg-1 , respectively. The quinoa seeds were characterized by low activity of protease inhibitors. The lowest inhibition of trypsin was determined for the UDEC-3, Faro Orange, and Titicaca cultivars, and the highest value was exhibited by the Titicaca White and UDEC-5 cultivars. Phenolics in the tested cultivars ranged from 7.1 g kg-1 (UDEC-3) to 10.6 g kg-1 (Temuko). The best antiradical properties were determined for Temuco and Rainbow (2.05 g TE kg-1 and 1.85 g TE kg-1 , respectively), while the Baer and Temuco cultivars were characterized by the highest reducing power (2.28 g TE kg-1 and 2.17 g TE kg-1 , respectively). CONCLUSION: This study has shown that quinoa cultivated in European countries is a good source of nutrients, dietary fiber, and antioxidants; however, its composition varies significantly. © 2019 Society of Chemical Industry.

Biochemical Properties of Polyphenol Oxidases from Ready-to-Eat Lentil (Lens culinaris Medik.) Sprouts and Factors Affecting Their Activities: A Search for Potent Tools Limiting Enzymatic Browning.

Enzymatic browning of sprouts during storage is a serious problem negatively influencing their consumer quality. Identifying and understanding the mechanism of inhibition of polyphenol oxidases (PPOs) in lentil sprouts may offer inexpensive alternatives to prevent browning. This study focused on the biochemical characteristics of PPOs from stored lentil sprouts, providing data that may be directly implemented in improving the consumer quality of sprouts. The purification resulted in approximately 25-fold enrichment of two PPO isoenzymes (PPO I and PPO II). The optimum pH for total PPOs, as well as for PPO I and PPO II isoenzymes, was 4.5-5.5, 4.5-5.0, and 5.5, respectively. The optimal temperature for PPOs was 35 °C. Total PPOs and the PPO I and PPO II isoenzymes had the greatest affinity for catechol (Km = 1.32, 1.76, and 0.94 mM, respectively). Ascorbic acid was the most effective in the inhibition of dark color formation by total PPOs, and showed ca. 62%, 43%, and 24% inhibition at 20-, 2-, and 0.2-mM concentrations. Ascorbic acid, l-cysteine, and sodium metabisulfite (20 mM) significantly inhibited color development in the reactions catalyzed by both isoenzymes of PPO. Ba2+, Fe3+, and Mn2+ (10 mM) completely inhibited PPO activity. This study of the effect of antibrowning compounds and cations on PPO activity provides data that can be used to protect lentil sprouts against enzymatic browning during storage and processing.

Nutritional quality of fresh and stored legumes sprouts - Effect of Lactobacillus plantarum 299v enrichment.

Nutrient content and digestibility as well as factors with a potentially negative effect on these parameters were studied in legume sprouts enriched with L. plantarum 299v. The nutrient digestibility and contents were not strongly affected by the co-culture of the probiotic and sprouts. The highest digestibility of starch was observed for adzuki bean preparations (from 91.6% to 95.5%), while the lowest value was noted for soybean preparations (from 49.6% to 60.8%). A slight decrease in starch digestibility was observed in adzuki and soybean sprouts enriched with the probiotic (by about 5% and 7% respectively). An increase in starch digestibility was noted in lentil and mung bean sprouts. A key influence on protein digestibility was exerted by the activity of trypsin and chymotrypsin inhibitors. Generally, there was no negative effect of the studied factors on starch digestibility. Most importantly, the control and probiotic-rich sprouts retained high quality after cold storage.

Lactobacillus plantarum 299V improves the microbiological quality of legume sprouts and effectively survives in these carriers during cold storage and in vitro digestion.

Probiotics improve consumers' health and additionally may positively influence the microbiological and organoleptic quality of food. In the study, legume sprouts were inoculated with Lactobacilllus plantarum 299V to produce a new functional product ensuring the growth and survival of the probiotic and high microbiological quality of the final product. Legume sprouts, which are an excellent source of nutrients, were proposed as alternative carriers for the probiotic. The key factors influencing the production of probiotic-rich sprouts include the temperature (25°C) of sprouting and methods of inoculation (soaking seeds in a suspension of probiotics). Compared to the control sprouts, the sprouts enriched with the probiotic were characterized by lower mesophilic bacterial counts. In the case of fresh and stored probiotic-rich sprouts, lactic acid bacteria (LAB) accounted for a majority of total microorganisms. The Lb. plantarum population was also stable during the cold storage. The high count of LAB observed in the digest confirmed the fact that the studied sprouts are effective carriers for probiotics and ensure their survival in the harmful conditions of the digestive tract in an in vitro model. Enrichment of legume sprouts with probiotics is a successful attempt and yields products for a new branch of functional foods.