Bożena Stodolak

Antioxidant properties of extracts from fermented and cooked seeds of Polish cultivars of Lathyrus sativus

Antiradical and total antioxidant activities of extracts from raw, prepared for inoculation, fermented (tempeh) and cooked seeds of grass pea (Lathyrus sativus Krab and Derek cultivars) were measured. Tempeh fermentation with Rhizopus oligosporus resulted in higher scavenging activity towards DPPH and ABTS(+) radicals which correlated well with the content of total phenols. In Derek cultivar, fermentation caused a significant inhibition of linoleic acid oxidation by methanol extracts. In buffer extracts the highest TAA values were observed in raw seeds. Cooking of seeds lowered RSA values as compared to fermentation, especially for the DPPH assay. Methanol and buffer extracts from cooked seeds showed prooxidant activity towards linoleic acid.

Effect of controlled lactic acid fermentation on selected bioactive and nutritional parameters of tempeh obtained from unhulled common bean (Phaseolus vulgaris) seeds

BACKGROUND Tempeh is a traditional Indonesian food of high nutritional quality obtained by fungal fermentation of dehulled, soaked and cooked legumes. The aim of this research was to study the effect of Lactobacillus plantarum DSM 20174 activity on selected parameters of tempeh made from unhulled seeds of common bean (Phaseolus vulgaris). Lactobacillus plantarum cells were applied during soaking of seeds (submerged fermentation) or during solid state fermentation with Rhizopus microsporus var. chinensis (co-cultivation). RESULTS Tempeh obtained from common beans contained 200 g kg⁻¹ protein of 34% in vitro bioavailability. Fungal fermentation caused decomposition of raffinose, stachyose and verbascose levels in seeds, on average by 93, 84 and 73% respectively. Enhanced antiradical (DPPH•, ABTS•+) capacity was accompanied by increased soluble phenol content. Application of Lactobacillus in the fermentation procedure increased tempeh protein and in vitro protein bioavailability by 18 and 17% respectively. Mixed culture tempeh contained lower levels of stachyose (25%), verbascose (64%) and condensed tannins (20%). Co-cultivation enhanced both DPPH•-scavenging activity and antioxidant capacity. CONCLUSION The application of Lactobacillus in most cases improved the nutritional parameters of tempeh from unhulled common beans. It may also be recommended to obtain products with diverse antioxidant properties as compared with fungal fermentation alone.

Development of complete hydrolysis of pectins from apple pomace.

Enzymatically extracted pectins have a more complex structure than those obtained by conventional methods. As a result, they are less susceptible to hydrolysis, which makes the precise determination of their composition difficult. The aim of the study was to develop a method of complete hydrolysis of enzymatically extracted apple pectins. Substrates were pectins isolated from apple pomace by the use of xylanase and multicatalytic preparation Celluclast and apple pomace. Hydrolysis was performed by a chemical method with 2M TFA at 100 °C and 120 °C and a combined acidic/enzymatic method. After hydrolysis, the contents of galacturonic acid and neutral sugars were measured by HPLC. Complete hydrolysis of polygalacturonic acid occurred after 2.5h incubation with 2M TFA at 120 °C. The efficient hydrolysis of neutral sugars in pectins was performed with 2M TFA at 100 °C for 2.5h. Monomers most susceptible to concentrated acid were rhamnose, mannose and arabinose.

The influence of inoculum composition on selected bioactive and nutritional parameters of grass pea tempeh obtained by mixed-culture fermentation with Rhizopus oligosporus and Aspergillus oryzae strains

Tempeh is a popular Indonesian product obtained from legume seeds by solid-state fermentation with Rhizopus sp. The aim of this research was to study the effect of simultaneous mixed-culture fermentation of grass pea seeds on selected parameters of products as compared to traditional tempeh. The inoculum contained different ratios of Rhizopus oligosporus and Aspergillus oryzae spores. The simultaneous fermentation of grass pea seeds with inoculum consisting of 1.2 × 106 R. oligosporus and 0.6 × 106 A. oryzae spores (per 60 g of seeds) resulted in a product of improved quality, as compared with traditionally made tempeh (obtained after inoculation with 1.2 × 106 R. oligosporus spores), at the same fermentation time. This product had radical scavenging ability 70% higher than the one obtained with pure R. oligosporus culture and contained 2.23 g/kg dm of soluble phenols. The thiamin and riboflavin levels were above three (340 µg/g dm) and two (50.50 µg/g dm) folds higher than in traditionally made tempeh, respectively. The product had 65% in vitro bioavailability of proteins and 33% in vitro bioavailability of sugars. It also contained 40% less 3-N-oxalyl-L-2, 3-diaminopropionic acid (0.074 g/kg dm), as compared to traditional tempeh.

Endo-xylanase and endo-cellulase-assisted extraction of pectin from apple pomace.

Pectins were extracted from apple pomace with monoactive preparation of endo-xylanase and endo-cellulase. The process was conducted for 10 h in conditions of pH 5.0 at 40 °C, with constant shaking. Endo-xylanase application resulted in the highest extraction efficiency of pectins (19.8%). The obtained polymer was characterised by a very high molecular mass, high level of neutral sugars - mainly arabinose, galactose and glucose, and very high DM (73.4). It also contained the highest level of protein and phenols. Pectin extracted with endo-cellulase had 1.5 fold lower molecular mass but contained significantly more GalA (70.5%) of a high degree of methylation (66.3%). The simultaneous application of both enzymatic preparations resulted in their cooperation, leading to a decrease of both the extraction efficiency and the molecular mass of pectin. However, this pectin was distinguished by the highest GalA (74.7%) and rhamnose contents.

Application of Celluclast 1.5L in apple pectin extraction.

Pectins were extracted from apple pomace with Celluclast 1.5L at a dose of 25, 50 and 75 μl per 1g of material. In obtained pectin, the galacturonic acid (GalA) content, the neutral sugars (NS) profile, the degree of methylation (DM) and acetylation (DAc), the molecular mass, protein, ash and polyphenol levels as well as antioxidant and antitumor activity were determined. The lowest dose of enzymatic preparation resulted in the yield of pectin isolation comparable with acidic treatment (15.3%). Application of higher dose caused further, almost 4% increase in polymer recovery. Enzymatically isolated pectin was characterised by larger molecular mass and contained more GalA of higher DM and DAc than polymer extracted with acid. It was also richer in protein and polyphenols, and had different NS profile, which resulted in higher antiradical activity as well as the ability to inhibit the proliferation and invasion of Caco-2 adenocarcinoma cells.

Effect of inoculated lactic acid fermentation on antinutritional and antiradical properties of grass pea (Lathyrus sativus 'Krab') flour.

Effect of Inoculated Lactic Acid Fermentation on Antinutritional and Antiradical Properties of Grass Pea (Lathyrus sativus ‘Krab’) Flour Grass pea flour was subjected to fermentation induced with Lactobacillus plantarum (5% (v/v) and 10% (v/v) inoculum representing 109 cells/mL). Processing (24 h fermentation) resulted in reducing levels of β-N-oxalyl-L-α-β-diaminopropionic acid (β- ODAP) (by nearly 10%) and trypsin inhibitors (by about 30%) as compared to raw seeds. Effective elimination of inositol phosphates was observed, however, the products of phytate hydrolysis (myoinositol triphosphate - IP3 and myoinositol tetraphosphate - IP4) were not detected in fermented grass pea flour. On the contrary, the amount of total phenolics distinctly increased, by 100% (5% (v/v) inoculum) and 200% (10% (v/v) inoculum). Antiradical activity (DPPH assay) of flour was partially improved due to bacterial fermentation. The flour of better quality was obtained as a result of the fermentation with 5% (v/v) inoculum as compared to 10% (v/v) inoculum.

Quinoa Tempe as a Value-Added Food: Sensory, Nutritional, and Bioactive Parameters of Products from White, Red, and Black Seeds

This experiment was aimed at comparing the sensory, nutritional, and bioactive parameters of tempe-type products obtained from quinoa seeds by means of solid-state fermentation with Rhizopus oligosporus. Quinoa tempe was compact and nonsporulating, of 61–65% moisture content. The products were favorably assessed by a sensory panel. Tempe from colored and white quinoa differed according to descriptive profiling of texture and flavor. As compared with the substrates, tempe had more protein (15–20%), free amino acids (5.5-fold to ninefold), and fiber (on average 48%, with increased share of soluble fraction), higher antiradical activity (160%), and higher reducing power. Quinoa tempe contained on average 160 g/kg dry matter (DM) of protein, 759 g/kg DM of carbohydrates, and 56 g/kg DM of fat. Black quinoa tempe was the richest in total fiber (180 g/kg DM) and insoluble fiber (155 g/kg DM). Products differed according to antioxidant parameters: white quinoa tempe had the highest phenols level (6.8 mg/g DM), A...

Fermentation of Colored Quinoa Seeds with Neurospora intermedia to Obtain Oncom-Type Products of Favorable Nutritional and Bioactive Characteristics

In this research, colored quinoa seeds were subjected to a modified oncom-type processing (precooking followed by solid-state fermentation with Neurospora intermedia) to obtain convenient food products of improved parameters. Compared with the raw material, the products contained a higher level of protein (on average by 44%, with an advantageous essential amino acid profile) and fiber (by 71%) but a lower amount of inositol phosphates (by 50%, with an increased share of InsP3 fraction in the profile). Fermented quinoa was enriched in carotenoids (6.5-fold) and riboflavin (fivefold). The antioxidant potential of oncom was also improved in respect to antiradical activity (on average by 39%) and reducing power. Of the red and black quinoa, the former substrate was processed into a product of better quality, containing a higher level of protein (214 g/kg dry matter [DM]), fiber (234 g/kg DM), carotenoids (81 mg/kg DM), and riboflavin (8 mg/kg DM), as well as antiradical activity (IC50 in ABTS⋅+ and DPPH⋅ assa...

The Effect of Germination on Antioxidant and Nutritional Parameters of Protein Isolates from Grass Pea (Lathyrus sativus) Seeds

The aim of this research was to study the antioxidant and nutritional (selected objects) properties of protein isolates obtained from grass pea seedlings as compared with soaked and raw seeds. Two percent extract of isolate from 5-day-old seedlings showed the highest total antioxidant activity (25%) and the ability to chelate Fe 2+ (2.35 mg/g d.m.) as compared with other isolates. Protein isolates from grass pea seeds had on average 89% total protein, 87% in vitro protein bioavailability, about 5574 TIU/g (d.m.) (trypsin inhibitors activity) and did not contain ODAP. Germination of seeds for 5 days considerably improved the in vitro bioavailability of isolates, by 12%, and profile of sulfur amino acids by 42%, in comparison with isolates obtained from the raw seeds. Isolates from 5-day-old grass pea seedlings had the best antioxidant properties and improved nutritional parameters (as compared with raw seeds), which makes them worthy of being considered as a potential food additive.