Water and energy saving bioprocess for bioethanol production from corn grain applying stillage liquid part recirculation

The distillery stillage is a major and arduous byproduct generated during ethanol production in distilleries. The liquid part of this stillage was proved that can be recycled in the ethanol production from corn, without disturbing the fermentation process. The corn seeds were fermented employing the conventional non-pressure method for gelatinizing as well as including a novelty: Recirculation system of distillery stillage liquid part instead of process water. The efficiency of fermentation and main chemical parameters of stillage were estimated. The liquid part of stillage was recycled 28 times. At these conditions distillery yeast Saccharomyces cerevisiae efficiently produced ethanol yielding 79.80% of the theoretical, keeping the vitality and quantity on the same level. However, recirculation of the liquid part of stillage caused protein and potassium increase in the wet cake what makes this product more attractive for fodder supplementation. It was proven that the addition of stillage liquid fraction to the mashing process instead of process water and 28 recirculation cycles in ethanol production from corn constitutes the way which could significantly reduce the water and energy consumption, what essentially reduce whole general production costs without ethanol efficiency decreasing.Keywords: Corn, stillage liquid part, recirculation, ethanol yieldAfrican Journal of Biotechnology Vol. 12(40), pp. 5950-595

Use of Saccharomyces cerevisiae and Zymomonas mobilis for bioethanol production from sugar beet pulp and raw juice

Biofuels have received great attention as an alternative energy source mainly due to limited oil reserves. Bioethanol can be produced from wide range of raw materials like starch, sucrose and cellulosic based sources. Sugar beet and raw juice, as its intermediate product, constitute very profitable substrates for bioethanol production, considering content of easy available fermentable sugars. In this study, sugar beet pulp and raw juice were fermented with Saccharomyces cerevisiae distillery yeasts and bacterium Zymomonas mobilis. Different medium dilution rate as well as yeasts preparations (Fermiol, Safdistil C-70) were investigated. Fermentation was run for 72 h at 30°C. Quality of obtained raw distillates was evaluated using GC method. S. cerevisiae distillery yeasts turned out to be more favourable microorganism than bacterium Z. mobilis for sucrose material fermentation. The ethanol yield obtained from sugar beet pulp and raw juice was 84 and 95% of theoretical yield, respectively. Fermentation of sugar beet raw juice obtained by pressing without enzymatic treatment yielded higher ethanol efficiency as compared to raw juice pressed with enzyme. Dilution ratio 1:1 for fermentation medium appeared to be profitable for effective fermentation process.Keywords: Sugar beet roots, raw juice, fermentation, bioethanol, Saccharomyces cerevisiae, Zymomonas mobilisAfrican Journal of BiotechnologyVol. 12(18), pp. 2464-247

Antimicrobial Food Packaging with Biodegradable Polymers and Bacteriocins

Innovations in food and drink packaging result mainly from the needs and requirements of consumers, which are influenced by changing global trends. Antimicrobial and active packaging are at the forefront of current research and development for food packaging. One of the few natural polymers on the market with antimicrobial properties is biodegradable and biocompatible chitosan. It is formed as a result of chitin deacetylation. Due to these properties, the production of chitosan alone or a composite film based on chitosan is of great interest to scientists and industrialists from various fields. Chitosan films have the potential to be used as a packaging material to maintain the quality and microbiological safety of food. In addition, chitosan is widely used in antimicrobial films against a wide range of pathogenic and food spoilage microbes. Polylactic acid (PLA) is considered one of the most promising and environmentally friendly polymers due to its physical and chemical properties, including renewable, biodegradability, biocompatibility, and is considered safe (GRAS). There is great interest among scientists in the study of PLA as an alternative food packaging film with improved properties to increase its usability for food packaging applications. The aim of this review article is to draw attention to the existing possibilities of using various components in combination with chitosan, PLA, or bacteriocins to improve the properties of packaging in new food packaging technologies. Consequently, they can be a promising solution to improve the quality, delay the spoilage of packaged food, as well as increase the safety and shelf life of food

Influence of green tea added to Cherry wine on phenolic content, antioxidant activity and alpha-glucosidase inhibition during an In vitro gastrointestinal digestion

Cherries are a good source of bioactive compounds, with high antioxidant activity as well as nutritional and therapeutic importance. In this study, cherry wines enriched with green tea infusion (mild and concentrated) were produced, and their biological properties were evaluated. During winemaking, the main vinification parameters (alcohol, reducing sugars, acidity, total polyphenol content) as well biological activity (antioxidant activity, alpha-glucosidase inhibition potential) were determined. An in vitro digestion process was also performed to evaluate the impact of the gastrointestinal environment on the biological stability of the wines, and to analyze the interactions of wine-intestinal microflora. The addition of green tea to the cherry wine significantly increased the total polyphenol content (up to 2.73 g GAE/L) and antioxidant activity (up to 22.07 mM TE/L), compared with the control wine. However, after in vitro digestion, a reduction in total polyphenols (53–64%) and antioxidant activity (38–45%) were noted. Wines fortified with green tea expressed a stronger inhibition effect on intestinal microflora growth, of which E. coli were the most sensitive microorganisms. The tea-derived bioactive compounds significantly increased the potential of alpha-glucosidase inhibition. The proposed wines could be a good alternative type of wine, with an increased polyphenol content and the potential to control the insulin response supporting therapy for diabetes

Nutritional Value and Biological Activity of Gluten-Free Bread Enriched with Cricket Powder

Cricket powder, described in the literature as a source of nutrients, can be a valuable ingredient to supplement deficiencies in various food products. Work continues on the implementation of cricket powder in products that are widely consumed. The aim of this study was to obtain gluten-free bread with a superior nutritional profile by means of insect powder addition. Gluten-free breads enriched with 2%, 6%, and 10% of cricket (Acheta domesticus) powder were formulated and extensively characterized. The nutritional value, as well as antioxidant and β-glucuronidase activities, were assessed after simulated in vitro digestion. Addition of cricket powder significantly increased the nutritional value, both in terms of the protein content (exceeding two-, four-, and seven-fold the reference bread (RB), respectively) and above all mineral compounds. The most significant changes were observed for Cu, P, and Zn. A significant increase in the content of polyphenolic compounds and antioxidant activity in the enriched bread was also demonstrated; moreover, both values additionally increased after the digestion process. The total polyphenolic compounds content increased about five-fold from RB to bread with 10% CP (BCP10), and respectively about three-fold after digestion. Similarly, the total antioxidant capacity before digestion increased about four-fold, and after digestion about six-fold. The use of CP also reduced the undesirable activity of β-glucuronidase by 65.9% (RB vs. BCP10) in the small intestine, down to 78.9% in the large intestine. The influence of bread on the intestinal microflora was also evaluated, and no inhibitory effect on the growth of microflora was demonstrated, both beneficial (Bifidobacterium and Lactobacillus) and pathogenic (Enterococcus and Escherichia coli). Our results underscore the benefits of using cricket powder to increase the nutritional value and biological activity of gluten-free food products

Thermodynamic Stability and Speciation of Ga(III) and Zr(IV) Complexes with High-Denticity Hydroxamate Chelators

Increasing attention has been recently devoted to 89Zr(IV) and 68Ga(III) radionuclides, due to their favorable decay characteristics for positron emission tomography (PET). In the present paper, a deep investigation is presented on Ga(III) and Zr(IV) complexes with a series of tri-(H3L1, H3L3, H3L4 and desferrioxamine E, DFOE) and tetrahydroxamate (H4L2) ligands. Herein, we describe the rational design and synthesis of two cyclic complexing agents (H3L1 and H4L2) bearing three and four hydroxamate chelating groups, respectively. The ligand structures allow us to take advantage of the macrocyclic effect; the H4L2 chelator contains an additional side amino group available for a possible further conjugation with a biomolecule. The thermodynamic stability of Ga(III) and Zr(IV) complexes in solution has been measured using a combination of potentiometric and pH-dependent UV-vis titrations, on the basis of metal-metal competition. The Zr(IV)-H4L2 complex is characterized by one of the highest formation constants reported to date for a tetrahydroxamate zirconium chelate (log β = 45.9, pZr = 37.0), although the complex-stability increase derived from the introduction of the fourth hydroxamate binding unit is lower than that predicted by theoretical calculations. Solution studies on Ga(III) complexes revealed that H3L1 and H4L2 are stronger chelators in comparison to DFOB. The complex stability obtained with the new ligands is also compared with that previously reported for other hydroxamate ligands. In addition to increasing the library of the thermodynamic stability data of Ga(III) and Zr(IV) complexes, the present work allows new insights into Ga(III) and Zr(IV) coordination chemistry and thermodynamics and broadens the selection of available chelators for 68Ga(III) and 89Zr(IV)