Juana Frias

Immunoreactivity reduction of soybean meal by fermentation, effect on amino acid composition and antigenicity of commercial soy products

Food allergy has become a public health problem that continues to challenge both the consumer and the food industry. The objectives of this study were to evaluate the reduction of immunoreactivity by natural and induced fermentation of soybean meal (SBM) with Lactobacillus plantarum, Bifidobacterium lactis, Saccharomyces cereviseae, and to assess the effect on amino acid concentration. Immunoreactivity of commercially available fermented soybean products and ingredients was also evaluated. ELISA and western blot were used to measure IgE immunoreactivity using plasma from soy sensitive individuals. Commercial soy products included tempeh, miso and yogurt. Fermented SBM showed reduced immunoreactivity to human plasma, particularly if proteins were <20kDa. S. cereviseae and naturally fermented SBM showed the highest reduction in IgE immunoreactivity, up to 89% and 88%, respectively, against human pooled plasma. When SBM was subjected to fermentation with different microorganisms, most of the total amino acids increased significantly (p<0.05) and only few of them suffered a decrease depending on the type of fermentation. All commercial soy containing products tested showed very low immunoreactivity. Thus, fermentation can decrease soy immunoreactivity and can be optimized to develop nutritious hypoallergenic soy products. However, the clinical relevance of these findings needs to be determined by human challenge studies.

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.

High-pressure improves enzymatic proteolysis and the release of peptides with angiotensin I converting enzyme inhibitory and antioxidant activities from lentil proteins.

Angiotensin I converting enzyme (ACE) inhibitory and antioxidant peptides are receiving attention due to their beneficial effects in the prevention/treatment of hypertension. The objective was to explore the effect of high hydrostatic pressure (HP) on proteolysis by different proteases and the release of bioactive peptides from lentil proteins. Pressurisation (100-300 MPa) enhanced the hydrolytic efficiency of Protamex, Savinase and Corolase 7089 compared to Alcalase. Proteolysis at 300 MPa led to a complete degradation of lentil proteins and increased peptide (<3 kDa) concentration by all enzymes. Proteolysis at 300 MPa by Savinase gave rise to lentil hydrolysates (S300) with the highest ACE-inhibitory and antioxidant activities that were retained upon in vitro gastrointestinal digestion. The peptides responsible for the multifunctional properties of S300 hydrolysate were identified as different fragments from storage proteins and the allergen Len c 1. These results support the potential of HP as a technology for the cost-effective production of bioactive peptides from lentil proteins during enzymatic proteolysis.

Fermentation enhances the content of bioactive compounds in kidney bean extracts.

The influence of solid (SSF) or liquid state fermentation (LSF) for 48 and 96 h on the production of water soluble extracts from kidney beans was investigated. SSF was carried out by Bacillus subtilis, whilst LSF was performed either by natural fermentation (NF) or by Lactobacillus plantarum strain (LPF). SSF extracts showed high soluble phenolic compound content (31-36 mg/g) and antioxidant activity (508-541 μg trolox equivalents/g), whilst LSF extracts exhibited potential antihypertensive activity due to their large γ-aminobutyric acid (GABA) content (6.8-10.6 mg/g) and angiotensin converting enzyme inhibitory (ACEI) activity (>90%). Therefore, fermentation can be considered as a valuable process to obtain bioactive ingredients from kidney beans, which could encourage their utilisation in the formulation of added-value functional foods.

Changes in carbohydrates during germination of lentils

ZusammenfassungIn der vorliegenden Arbeit wurde der Einfluß der Keimung auf die Gehalte an löslichen Kohlenhydraten, Gesamt- und verdaulicher Stärke und Komponenten der Rohfaser (“neutral detergent fiber”, Cellulose und Hemicellulose), in zwei Linsensorten (Lens culinaris medicus var. vulgaris und variabilis) untersucht. Der Gesamtzuckergehalt nimmt durch die Keimung bei beiden Sorten ab (von 4,3% bis 2,0% und von 5,3% bis 2,2%). Glucose, die sich in rohen Samen nicht findet, lag bei 0,6% und 0,7% in den gekeimten Linsen. Fructose und Sucrose änderten sich nur wenig. Die Raffinose-Oligosaccharide sind bei den gekeimten Linsen nicht vorhanden. Die Gesamt-Stärke nimmt deutlich während der Keimung ab (von 60,27% bis 41,39% und von 57,41% bis 36,39%), aber die Verdaulichkeit der Stärke wurde signifikant verbessert. Die Gehalte an “neutral detergent fiber” und Hemicellulose bei gekeimten Linsen waren niedriger als bei rohen Linsen, aber die Cellulose- und Ligningehalte waren nach der Keimung größer. Der Proteinnährwert bei beiden Linsensorten kann durch die Keimung verbessert werden.SummaryThe effect of germination on soluble carbohydrates, total and digestible starch, and components of dietary fiber (neutral detergent fiber, cellulose and hemicellulose) in two varieties of lentils (Lens culinaris medicus var. vulgaris and variabilis) were investigated. In germinated lentils the amount of total soluble sugars decreased (from 4.3% to 2.0% and from 5.3% to 2.2%, respectively); glucose, not present in raw seeds, was relatively high (0.6% and 0.7%), fructose increased slightly, and sucrose decreased slightly. The oligosaccharides of the raffinose family disappeared from germinated seeds. Total starch decreased considerably in germinated lentils (from 60.3% to 41.4% and from 57.4% to 36.4%), but the digestibility of the starch was greatly improved. In germinated lentils, the content of neutral detergent fiber and hemicellulose were lower but that of cellulose and lignin were higher than in raw lentils. Thus, the nutritive value of both varieties of lentils may increase with germination processes.

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.

Maximising the phytochemical content and antioxidant activity of Ecuadorian brown rice sprouts through optimal germination conditions

Germinated brown rice (GBR) is considered a healthy alternative to white rice in the fight against chronic diseases. As the functional quality of GBR depends on genotype and germination conditions, the objectives were to identify suitable Ecuadorian brown rice cultivars and optimal germination time and temperature to maximise γ-aminobutyric acid (GABA), total phenolics compounds (TPC) and antioxidant activity of GBR. Regression models for the prediction of phytochemical composition and antioxidant activity in GBR were also obtained. Germination improved GABA, TPC and antioxidant activity in all cultivars. Maximum GABA and antioxidant activity were attained at 34 °C for 96 h, while the highest TPC was found at 28 °C for 96 h in all cultivars. GBR cv. GO displayed the highest antioxidant activity and cv. 15 was the most effective at accumulating GABA and TPC in the optimal germination conditions. Therefore, Ecuadorian GBR could be used for the preparation of functional foods serving as preventative strategies in combating chronic diseases.

The future of lupin as a protein crop in Europe

Europe has become heavily dependent on soya bean imports, entailing trade agreements and quality standards that do not satisfy the European citizen’s expectations. White, yellow, and narrow-leafed lupins are native European legumes that can become true alternatives to soya bean, given their elevated and high-quality protein content, potential health benefits, suitability for sustainable production, and acceptability to consumers. Nevertheless, lupin cultivation in Europe remains largely insufficient to guarantee a steady supply to the food industry, which in turn must innovate to produce attractive lupin-based protein-rich foods. Here, we address different aspects of the food supply chain that should be considered for lupin exploitation as a high-value protein source. Advanced breeding techniques are needed to provide new lupin varieties for socio-economically and environmentally sustainable cultivation. Novel processes should be optimized to obtain high-quality, safe lupin protein ingredients, and marketable foods need to be developed and offered to consumers. With such an integrated strategy, lupins can be established as an alternative protein crop, capable of promoting socio-economic growth and environmental benefits in Europe.