Optimised Degradation of Lignocelluloses by Edible Filamentous Fungi for the Efficient Biorefinery of Sugar Beet Pulp.

The degradation of the complex structure of lignocellulosic biomass is important for its further biorefinery to value-added bioproducts. The use of effective fungal species for the optimised degradation of biomass can promote the effectiveness of the biorefinery of such raw material. In this study, the optimisation of processing parameters (temperature, time, and s/w ratio) for cellulase activity and reducing sugar (RS) production through the hydrolysis of sugar beet pulp (SBP) by edible filamentous fungi of Aspergillus, Fusarium, Botrytis, Penicillium, Rhizopus, and Verticillium spp. was performed. The production of RS was analysed at various solid/water (s/w) ratios (1:10-1:20), different incubation temperatures (20-35 °C), and processing times (60-168 h). The Aspergillus niger CCF 3264 and Penicillium oxalicum CCF 3438 strains showed the most effective carboxymethyl cellulose (CMC) degrading activity and also sugar recovery (15.9-44.8%) from SBP biomass in the one-factor experiments. Mathematical data evaluation indicated that the highest RS concentration (39.15 g/100 g d.w.) and cellulolytic activity (6.67 U/g d.w.) could be achieved using A. niger CCF 3264 for the degradation of SBP at 26 °C temperature with 136 h of processing time and a 1:15 solid/water ratio. This study demonstrates the potential of fungal degradation to be used for SBP biorefining.

Influence of Enzymatic Hydrolysis on Composition and Technological Properties of Apple Pomace and Its Application for Wheat Bread Making.

The aim of this work was to evaluate the influence of enzymatic hydrolysis on dietary fiber, phenolic compounds and technological properties of apple pomace as wheat bread supplement. Apple pomace was hydrolyzed with Viscozyme® L, Pectinex® Ultra Tropical, Celluclast® 1.5 L for 1 and 5 h. Soluble (SDF) and insoluble (IDF) dietary fiber, reducing sugars and the total phenolic contents (TPC), along with the technological properties (water and oil retention capacities, solubility index, emulsion stability) of treated apple pomace were evaluated. The prebiotic activity of apple pomace water-soluble fraction on two probiotic strains Lactobacillus acidophilus DSM 20079 and Bifidobacterium animalis DSM 20105 was investigated. Treatment with Celluclast® 1.5 L increased SDF, reducing sugars, SDF/IDF ratio and decreased IDF of apple pomace. While treatment with Viscozyme® L, Pectinex® Ultra Tropical increased reducing sugars, solubility index and TPC, but in most cases reduced oil and water retention capacities, decreased SDF and IDF content. All apple pomace extracts promoted growth of probiotic strains. Addition of 5% of apple pomace hydrolyzed with Celluclast® 1.5 L did not have negative impact on wheat bread, while addition of other enzymatically hydrolyzed apple pomaces decreased pH, specific volume and porosity of wheat bread. Obtained results suggest that apple pomace enzymatically hydrolyzed with Celluclast® 1.5 L can be potentially used for wheat bread supplementation with dietary fiber.

Technological Properties and Composition of Enzymatically Modified Cranberry Pomace.

Cranberry pomace obtained after juice production is a good source of dietary fiber and other bioactive compounds. In this study, cranberry pomace was hydrolyzed with Viscozyme® L, Pectinex® Ultra Tropical, Pectinex® Yieldmash Plus, and Celluclast® 1.5L (Novozyme A/S, Denmark). The soluble and insoluble dietary fiber was determined using the Megazyme kit, while the changes in mono-, disaccharide and oligosaccharides' contents were determined using HPLC-RI; the total phenolic contents were determined by Folin-Ciocalteu's Assay. Prebiotic activity, using two probiotic strains Lactobacillus acidophilus DSM 20079 and Bifidobacterium animalis DSM 20105, was investigated. The technological properties, such as hydration and oil retention capacity, were evaluated. The enzymatic treatment increased the yield of short-chain soluble saccharides. The highest oligosaccharide content was obtained using Viscozyme® L and Pectinex® Ultra Tropical. All of the tested extracts of cranberry pomace showed the ability to promote growth of selected probiotic bacteria. The insoluble dietary fiber content decreased in all of the samples, while the soluble dietary fiber increased just in samples hydrolyzed with Celluclast® 1.5L. The highest content of total phenolic compounds was obtained using Viscozyme® L and Pectinex® Ultra Tropical (10.9% and 13.1% higher than control, respectively). The enzymatically treated cranberry pomace exhibited lower oil and water retention capacities in most cases. In contrast, water swelling capacity increased by 23% and 70% in samples treated with Viscozyme® L and Celluclast® 1.5L, respectively. Enzymatically treated cranberry pomace has a different composition and technological properties depending on the enzyme used for hydrolysis and can be used in various novel food products.

Characterization of Berry Pomace Powders as Dietary Fiber-Rich Food Ingredients with Functional Properties.

This study aimed to evaluate and compare the dried pomace powder of cranberries, lingonberries, sea buckthorns, and black currants as potential food ingredients with functional properties. The composition and several physicochemical and adsorption properties associated with their functionality were investigated. Tested berry pomace powders were rich in dietary soluble fiber (4.92-12.74 g/100 g DM) and insoluble fiber (40.95-65.36 g/100 g DM). The highest level of total phenolics was observed in the black currant pomace (11.09 GAE/g DM), whereas the sea buckthorn pomace revealed the highest protein concentration (21.09 g/100 g DM). All the berry pomace powders that were tested exhibited good water-holding capacity (2.78-4.24 g/g) and swelling capacity (4.99-9.98 mL/g), and poor oil-binding capacity (1.09-1.57 g/g). The strongest hypoglycemic properties were observed for the lingonberry and black currant pomace powders. The berry pomace powders presented effective in vitro hypolipidemic properties. The cholesterol-binding capacities ranged from 21.11 to 23.13 mg/g. The black currant and cranberry pomace powders demonstrated higher sodium-cholate-binding capacity than those of the lingonberry and sea buckthorn pomace powders. This study shows promising results that the powders of tested berry pomace could be used for further application in foods.

Non-conventional yeasts for food and additives production in a circular economy perspective.

Yeast species have been spontaneously participating in food production for millennia, but the scope of applications was greatly expanded since their key role in beer and wine fermentations was clearly acknowledged. The workhorse for industry and scientific research has always been Saccharomyces cerevisiae. It occupies the largest share of the dynamic yeast market, that could further increase thanks to the better exploitation of other yeast species. Food-related 'non-conventional' yeasts (NCY) represent a treasure trove for bioprospecting, with their huge untapped potential related to a great diversity of metabolic capabilities linked to niche adaptations. They are at the crossroad of bioprocesses and biorefineries, characterized by low biosafety risk and produce food and additives, being also able to contribute to production of building blocks and energy recovered from the generated waste and by-products. Considering that the usual pattern for bioprocess development focuses on single strains or species, in this review we suggest that bioprospecting at the genus level could be very promising. Candida, Starmerella, Kluyveromyces and Lachancea were briefly reviewed as case studies, showing that a taxonomy- and genome-based rationale could open multiple possibilities to unlock the biotechnological potential of NCY bioresources.

Effect of Lactic Acid Fermentation on Quinoa Characteristics and Quality of Quinoa-Wheat Composite Bread.

The application of selected starter cultures with specific properties for fermentation may determine steady lactic acid bacteria (LAB) variety and the characteristics of fermented products that influence nutritional value, the composition of biologically active compounds and quality. The aim of this research was to evaluate the influence of different LAB on the biochemical characteristics of fermented quinoa. Moreover, total phenolic content (TPC), and the antimicrobial and antioxidant activities of protein fractions isolated from quinoa previously fermented with LAB were investigated. Quinoa additives, including quinoa fermented with Lactobacillus brevis, were incorporated in a wheat bread recipe to make nutritionally fortified quinoa-wheat composite bread. The results confirmed that L. plantarum, L. brevis, and L. acidophilus were well adapted in quinoa medium, confirming its suitability for fermentation. LAB strains influenced the acidity, L/D-lactic acid content, enzyme activity, TPC and antioxidant activity of fermented quinoa. The maximum phytase activity was determined in quinoa fermented with L. brevis. The results obtained from the ABTS radical scavenging assay of protein fractions confirmed the influence of LAB strain on the antioxidant activity of protein fractions. The addition of 5 and 10% of quinoa fermented with L. brevis did not affect the total titratable acidity of wheat bread, while 10% of fermented quinoa with L. brevis resulted in a higher specific volume. Fermented quinoa additives increased the overall acceptability of bread compared with unfermented seed additives.

Ultrasound-Assisted Extraction and Assessment of Biological Activity of Phycobiliprotein-Rich Aqueous Extracts from Wild Cyanobacteria (Aphanizomenon flos-aquae).

Cyanobacteria are photosynthetic microorganisms that are considered as an important source of bioactive metabolites, among which phycobiliproteins (PBPs) are a class of water-soluble macromolecules of cyanobacteria with a wide range of applications. Massive proliferation of cyanobacteria can lead to excessive surface water blooms, of which removal, as a management measure, should be prioritized. In this study, the utilization of wild cyanobacteria biomass (Aphanizomenon flos-aquae) for extraction of phycobiliproteins is reported. Extraction of phycobiliproteins by conventional methods, such as homogenization, freeze-thaw cycles, and solid-liquid extraction, were optimized prior to ultrasound-assisted extraction. Standardization of ultrasonication for different parameters, such as ultrasonication amplitude (38, 114, and 190 µm) and ultrasonication time (1, 5.5, and 10 min), was carried out using a central composite design and response surface methodology for each of the primary techniques. A substantial increase on the individual and total phycobiliprotein yields was observed after ultrasonic treatment. The highest total PBP yield (115.37 mg/g of dry weight) was observed with samples treated with a homogenizer (30 min, 30 °C, and 1 cycle) combined with ultrasound treatment (8.7 min at 179 µm). Moreover, in vitro antioxidant capacity was observed for the obtained extracts in the Folin-Ciocalteu and ABTS* + assays. In addition, a cytotoxic effect against C6 glioma cells was observed for A. flos-aquae PBPs. Conclusively, wild cyanobacteria could be considered as an alternative feedstock for recovery of PBPs.

Non-Alcoholic Beverages from Fermented Cereals with Increased Oligosaccharide Content.

The aim of this study is to develop a new technology for making traditional Lithuanian non-alcoholic beverage kvass from fermented cereals by extending the spectrum of raw materials (extruded rye) and applying new biotechnological resources (xylanolytic enzymes and lactic acid bacteria (LAB)) to improve its functional properties. Arabinoxylans in extruded rye were very efficiently hydrolysed into oligosaccharides by xylanolytic complex Ceremix Plus MG. Using Ceremix Plus MG and LAB fermentation, the yield of arabinoxylooligosaccharides and xylooligosaccharides in beverage was increased to 300 and 1100 mg/L, respectively. Beverages fermented by LAB had lower pH values and ethanol volume fraction compared to the yeast-fermented beverage. The acceptability of the beverage fermented by Lactobacillus sakei was higher than of Pediococcus pentosaceus- or yeast- -fermented beverages and similar to the acceptability of commercial kvass made from malt extract. The results showed that extruded rye, xylanolytic enzymes and LAB can be used for production of novel and safe high-value non-alcoholic beverages.

Benefits of ß-xylanase for wheat biomass conversion to bioethanol.

BACKGROUND: The efficiency of bioethanol production from wheat biomass is related to the quality of end products as well as to safety criteria of co-products such as distiller's dried grains with solubles (DDGS). The inclusion of a new biocatalyst for non-starch polysaccharide degradation in fermentation processes could be one of the solutions. The objective of this study was to evaluate the influence of ß-xylanases in combination with traditional amylolytic enzymes on the efficiency of bioethanol production and DON detoxification during fermentation of Fusarium-contaminated wheat biomass with high concentration of deoxynivalenol (DON; 3.95 mg kg(-1)). RESULTS: The results showed that the negative effect of Fusarium spp. on yield and quality of bioethanol could be eliminated by the application of Trichoderma reesei xylanase in combination with amylolytic enzymes. This technological solution allowed to increase the concentration of ethanol in the fermented wort by 35.3% and to improve the quality of bioethanol by decreasing the concentrations of methanol, methyl acetate, isoamyl and isobutyl alcohols. Mass balance calculations showed that DDGS was the main source of DON contamination, comprising 74% of toxin found in wheat biomass. By using new enzyme combination for wheat biomass saccharification, a higher level of detoxification (41%) of DON was achieved during the fermentation process. CONCLUSION: The addition of Trichoderma reesei xylanase played a positive role in bioethanol production from Fusarium-contaminated wheat biomass, indicating that the yeast-growing medium was enriched during the enzymatic treatment.