Concepción Vidal-Valverde

Antioxidant and antihypertensive properties of liquid and solid state fermented lentils

The effect of liquid (LSF) and solid state fermentation (SSF) of lentils for production of water-soluble fractions with antioxidant and antihypertensive properties was studied. LSF was performed either spontaneously (NF) or by Lactobacillus plantarum (LP) while SSF was performed by Bacillus subtilis (BS). Native lactic flora in NF adapted better than L. plantarum to fermentative broth and BS counts increased 4.0 logCFU/g up to 48 h of SSF. LSF water-soluble fractions had higher (P ≤ 0.05) free amino groups, GABA content, antioxidant and angiotensin I-converting enzyme inhibitory (ACEI) activities than SSF. In addition, GABA and ACEI activity of LSF increased in a time-dependent manner. Proteolysis by BS was limited, with slight changes in free amino groups, while GABA, total phenolic compounds and antioxidant capacity increased throughout fermentation. Higher antihypertensive potential was observed in NF (96 h) characterised by the highest GABA content (10.42 mg/g extract), ACE-inhibitory potency (expressed as IC(50)) of 0.18 mg protein/ml and antioxidant capacity of 0.26 mmol Trolox equivalents/g extract. Therefore, water-soluble fermented lentil extracts obtained by LSF are particularly promising as functional ingredients in preventing hypertension.

Food safety evaluation of broccoli and radish sprouts.

Three cultivars of broccoli seeds (Brassica oleracea var. italica), cv. Tiburon, cv. Belstar and cv. Lucky, and two cultivars of radish seeds (Raphanus sativus), cv. Rebel and cv. Bolide, were germinated for three and five days and safety aspects such as microbiological counts and biogenic amines were investigated. Cytotoxicity evaluation was also carried out. Broccoli and radish sprouts contained numbers of mesophilic, psychrotrophic, total and faecal coliform bacteria which are the usual counts for minimally processed germinated seeds. Putrescine, cadaverine, histamine, tyramine, spermidine and spermine increased during sprout production although these levels were below those permitted by legislation (5 mg/100 g of edible food). Broccoli and radish sprouts demonstrated no toxic effects on proliferation and viability of HL-60 cells and should be included in our diets as healthy and safe fresh foods.

Alpha-Galactosides: Antinutritional Factors or Functional Ingredients?

This review focuses on updated information about α-galactosides, their chemical structure, biosynthesis, plant physiological functions, occurrence in foods, positive and negative physiological effects in animals, changes during food processing, and their potential application as prebiotics in the food industry. Although α-galactosides are considered as the main flatus-causing factors, they are also involved in several important functions during plant and seed development and beneficially stimulate the growth and activity of living bifidobacteria and lactobacilli in the human colon. We focus here also on legumes as a source of this kind of prebiotics as potential health promoters.

Influence of soaking and cooking on the thiamin, riboflavin and niacin contents of legumes

Abstract The effects on thiamin, riboflavin and niacin contents of faba beans ( Vicia faba , L.), chickpeas ( Cicer arietinum , L.) and lentils ( Lens culinaris , L.), of soaking in different solutions (citric acid solution pH 4.96±0.02, distilled water pH 7.00±0.02 and sodium bicarbonate solution pH 7.85±0.02) and cooking of the presoaked legumes in distilled water have been studied. The main factor determining the vitamin retention after each treatment was the legume genus. Soaking faba beans for 9 h produced losses of 0 and 15% thiamin, 0 and 11% riboflavin and no changes in niacin content ( P ⩽0.05). In the case of chickpeas the effect of the treatment was more acute. Losses of 0–18% thiamin, 0–4% riboflavin and 0–46% available niacin was observed while in lentils, the thiamin and available niacin contents decreased by 5–10% and 26–42%, respectively and the riboflavin increased by up to 98%. In general, vitamin losses were greater when soaking was carried out in alkaline solution. In most of the studied legumes, cooking produced further decreases in vitamins. Faba beans lost up to 35 and 32%, respectively, of their thiamin and available niacin contents, while riboflavin was not affected. Chickpeas and lentils were more liable to lose their vitamins: up to 51% thiamin, 66% riboflavin and 78% available niacin in chickpeas and up to 61% thiamin and 61% available niacin in lentils. Cooking did not cause any additional loss of the riboflavin content of lentils. With few exceptions, cooking caused greater vitamin losses when a prior soaking was carried out in alkaline solution.

Natural fermentation of lentils : Influence of time, concentration, and temperature on the kinetics of hydrolysis of inositol phosphates

Lentil (Lens culinaris var vulgaris) flour was naturally fermented for 96 h at various conditions of concentration (79, 150 and 221 g litre -1 ) and temperature (28°C, 35°C and 42°C). The content of total inositol phosphates (IP-total) and individual inositol phosphates (hexa- (IP 6 ), penta- (IP 5 ), tetra- (IP 4 ) and tri- (IP 3 ) phosphates) were analysed to establish the changes of these compounds during natural fermentation of lentils. The preparation of the lentil suspension brought about 16-27% reduction of the total inositol phosphates. At the end of 96 h of natural fermentation maximum IP loss (70-75%) was achieved for an experiment carried out at minimum concentration. For IP 6 , the largest decrease was achieved at the highest temperature, the fermentation condition that also brought about the highest IP 5 content.

Lentil Starch Content and its Microscopical Structure as Influenced by Natural Fermentation

Lentil seeds (Lens culinaris var. vulgaris, cultivar Magda-20) were allowed to ferment naturally at different lentil flour concentrations (79 g/L, 150 g/L and 221 g/L) and temperatures (28 °C, 35 °C and 42 °C). During fermentation, samples were taken at 24 h intervals. The changes in starch content in all samples were studied. Scanning electron microscopy (SEM) was used to investigate changes in samples fermented for 96 h at two different concentrations (79 g/L and 221 g/L) and two different temperatures (28 °C and 42 °C). A considerable decrease in starch content was observed at 0 h of fermentation, defined as the time when the lentil flour was completly suspended at the established temperature. Once fermentation began, flour concentration and temperature modified starch content. Fermentation brought about a general decrease in starch content and a 32—37 % dry matter content was found in the samples after 96 h. Microscopical studies showed that endocorrosion, i.e., breakdown starting from the center of starch granules, was the main pattern observed during lentil fermentation.

Effect of natural fermentation on carbohydrates, riboflavin and trypsin inhibitor activity of lentils.

ZusammenfassungEs wurde die Linsenfermentation durch natürlich vorkommende Mikroorganismen während 4 Tage durchgeführt. Die Temperatur wurde bei 30°C gehalten. Durch die Vergärung fällt der pH-Wert auf 3,8. α-Galaktoside und Saccharose wurden in den Linsen nicht nachgewiesen, jedoch eine signifikante Zunahme des Fructosegehaltes. Es zeigte sich, daß in den Linsen die neutrale Detergent-Faser, der Cellulose- und Hemicellulosegehalt und die Trypsininhibitor-Aktivität abnimmt, aber der Lignin- und Riboflavingehalt zunimmt.AbstractLentils were subjected to natural fermentation for 4 days at 30°C. The pH value fell to 3.8 during the process. α-Galactosides and sucrose were not detected in fermented lentils but a significant increase in the fructose content was observed. In fermented lentils the neutral detergent fibre, cellulose and hemicellulose contents decreased and the lignin content increased. After fermentation the riboflavin content was higher and the trypsin inhibitor activity decreased.

Raffinose family of oligosaccharides from lupin seeds as prebiotics: Application in dairy products

The raffinose family of oligosaccharides (RFOs) isolated from lupin seeds (Lupinus albus var. Multolupa) was evaluated for bifidogenic effects during the manufacture of probiotic fermented milk. A mixed starter inoculum was composed of Bifidobacterium lactis Bb-12 and Lactobacillus acidophilus (1:1). Lupins are a rich source of RFOs that can be used as functional food ingredients. The addition of RFOs to milk increased B. lactis Bb-12 and L. acidophilus populations at the final fermentation time compared with controls. Final fermentation products are positively affected by addition of RFOs, and time of fermentation was reduced from 12 to 10 h. When RFOs were added to milk, they were preferentially used as a carbon source (57.7%) compared with lactose (23.7%) at the end of fermentation. These results suggest that the eventual choice of B. lactis Bb-12 and L. acidophilus in a mixed culture at a 1:1 ratio and addition of RFOs to produce a fermented milk product would have the advantages of rapid growth and acidificationrate and would likely increase the probiotic effect of the final functional product.

Natural fermentation of lentils. Influence of time, concentration and temperature on protein content, trypsin inhibitor activity and phenolic compound content.

Lentil (Lens culinaris var. vulgaris) flour was naturally fermented for 4 days at different temperatures (28°C, 35°C and 42°C) and concentrations (79 g/1, 150 g/1 and 221 g/1). Samples were analysed to establish the changes of total protein content and in vitro protein digestibility, trypsin inhibitor activity (TIA) and phenolic compound content during natural fermentation of lentils. The preparation of lentil flour suspensions to be fermented caused a slight increase in total protein and in vitro protein digestibility content, a decrease of TIA and a sharp decrease the tannin/catechin ratio. During the whole fermentation procedure, the minimum initial lentil concentration and temperature used (79 g/1, 28°C) achieved the maximum protein content and the lowest tannin/catechin ratio. The TIA was more affected by temperature than by concentration, and a 62.5% reduction was observed at 42°C and 79 g/1.

Bioactive Compounds, Myrosinase Activity, and Antioxidant Capacity of White Cabbages Grown in Different Locations of Spain

The influence of two Spanish growing locations with well-differentiated climatic conditions (northern and eastern areas) on the main bioactive compounds, glucosinolates (GLS), total phenolic compounds (TPC), and vitamin C, as well as myrosinase activity and antioxidant capacity in five white cabbage ( Brassica oleracea L. var. capitata) cultivars was investigated. Cabbages with the highest concentration of total GLS presented the highest vitamin C level (r = 0.75, P ≤ 0.05) and the lowest antioxidant capacity (r = -0.76, P ≤ 0.05). The cultivars with the highest vitamin C content had the lowest myrosinase activity (r = -0.89, P ≤ 0.05) and antioxidant capacity (r = -0.86, P ≤ 0.05), whereas those with the largest TPC amount showed the highest antioxidant capacity (r = 0.71, P ≤ 0.05). Cabbage cultivars grown in the northern area of Spain with low temperatures and radiation led to higher mean values of myrosinase activity (29.25 U/g dm), TPC (10.0 GAE mg/g dm), and antioxidant capacity (81.6 μmol Trolox/g dm), whereas cultivars grown in the eastern area with high temperature and radiation led to larger mean values of GLS (14.3 μmol/g dm) and vitamin C (5.3 mg/g dm). The results of this investigation provide information regarding the most suitable Spanish growing location to produce white cabbage with an optimized content of health-promoting compounds.