Progresses in the production of ethanol from lignocellulosic biomass using Saccharomyces cerevisiae by fermentation engineering

Ethanol fermentation is a biological procedure which converts sugars such as glucose, fructose, and sucrose into cellular energy, producing ethanol and carbon dioxide as by-products. Since yeasts perform this conversion in the absence of oxygen, alcoholic fermentation is generally considered to be an anaerobic process. Ethanol fermentation has many uses, including the production of alcoholic beverages, the production of ethanol fuel, and bread making. The increasing demand for biofuels around the globe has also prompted the necessity to seek other means to meet the demands. In this review, the general ideologies, methodologies, general chemistry and biochemistry and conditions of the production of ethanol by fermentation engineering using Saccharomyces cerevisiae are highlighted. The quest to reduce pressure on staple foods has necessitated the attention now given to the use of lignocellulose biomass, despite the complexity of the process. It concludes by suggesting ways to improve yield and commercialization of the use of lignocellulosic biomass for ethanol fermentation.

Label information, nutritional composition and screening for bromate in breads sold in Umuahia, Abia State, Nigeria

Non-use of potassium bromate in bread making and printing of reproducible nutrition information/claims on bread labels are vital for consumers’ rights and protection in Nigeria. These norms are rarely observed by bread makers in Umuahia. This study evaluated nutrition information on labels, presence of potassium bromate, chemical composition and sensory characteristics of breads sold in Umuahia. Two structured questionnaires were constructed. The first was administered to 15 randomly selected full-time bread vendors in Umuahia metropolis to identify brands of market bread. The second was designed to analyze sensory quality of breads. Five sliced and five unsliced bread samples randomly selected from identified markets were analyzed for sensory properties using a 20-member sensory panelist, and for nutrient and phytochemical composition. Twenty-seven bread samples were identified; all labeled bromate-free, had varying recipes and nutrient claim/information on labels. The bread samples were bromate-free, high in carbohydrate (49.20% in B10 to 65.69% in B8) and moisture (22.67% in B8 to 38.16% in B10), but relatively low in crude protein (6.65% in B3 to 9.45% in B7) and fat (0.26% in B8 to 0.66% in B1). Ash contents ranged from 1.26% in B6 to 1.86% in B3and fiber contents from 1.24% in B2 to 1.76% in B5. Phytonutrients were low; and oxalate content ranged from 0.66 to 0.95%, tannin from 87.78 to 125.40 mg 100g–1 and phytate from 2.02 to 3.03 mg 100g–1. The bread samples had sensory scores ranging from 4.60 to 8.10 for over-all acceptability. They were all acceptable to panelists, but with B1 (sliced) and B8 (unsliced) most acceptable. Bread samples sold in Umuahia were bromate-free, varied in recipe, nutrition claims, and nutrient composition but were acceptable to panelists.

Changes in the Polyphenolic Profile and Antioxidant Activity of Wheat Bread after Incorporating Quinoa Flour

Quinoa is a trend and a promising functional food ingredient. Following previous research into the impact of incorporating quinoa flour on the polyphenol content and antioxidant activity of bread, this study aimed to bridge an existing gap about the qualitative and quantitative polyphenolic profiles of such bread. The UPLC-MS/MS analysis showed that quinoa bread, made with 25% quinoa flour of a black variety, presented more compounds than refined-wheat bread, and levels were remarkably higher in many cases. Consequently, the quinoa bread presented clearly improved polyphenolic content than the wheat bread (12.8-fold higher considering the sum of extractable and hydrolyzable polyphenols), as supported by greater antioxidant activity (around 3-fold). The predominant compounds in the extractable fraction of quinoa bread were p-hydroxybenzoic acid and quercetin (50- and 64-fold higher than in wheat bread, respectively) and rutin (not detected in wheat bread), while ferulic and sinapic acids were the most abundant compounds in the hydrolyzable fraction (7.6- and 13-fold higher than in wheat bread, respectively). The bread-making impact was estimated, and a different behavior for phenolic acids and flavonoids was observed. Extractable phenolic acids were the compounds that decreased the most; only 2 of 12 compounds were enhanced (p-hydroxybenozoic and rosmarinic acid with increments of 64% and 435%, respectively). Flavonoids were generally less affected, and their concentrations considerably rose after the bread-making process (7 of the 13 compounds were enhanced in the extractable fraction) with especially noticeably increases in some cases; e.g., apigenin (876%), kaempferol (1304%), luteolin (580%) and quercetin (4762%). Increments in some extractable flavonoids might be explained as a consequence of the release of the corresponding hydrolyzable forms. The present study provides new information on the suitability of quinoa-containing bread as a suitable vehicle to enhance polyphenols intake and, hence, the antioxidant activity in daily diets.

Application of FMEA and Pareto Analysis Methods in the Process of Industrial Bread Making in Romania

Zero defects or nearly zero faulty products production process represents a new and important concern towards quality control of production systems. The requirement of a pertinent statistical control is important for identifying and monitoring defects, the main source of defects that occur in industrial bread making process. The current study was focused on applying two analysis methods Failure Mode and Effects Analyses, abbreviated FMEA and Pareto. Analysis concerning two technological stages that were considered as having a major impact on the quality of the final products. It was observed that the percent of nonconformities decreased in a significant manner – from 30% in 2018 to 5% in 2019 by applying the FMEA analysis. Also, the Pareto diagram showed that the application of several corrective measurements conducted to important decreases of Risk Priority Number from 288 to 128 and the severity decreased from 8 to 5 in the mixing process and from 128 to 81 for the baking process.

Effect of Hulless Barley Flours on Dough Rheological Properties, Baking Quality, and Starch Digestibility of Wheat Bread

Hulless barley (Hordeum vulgare L.), also known as highland barley, contains nutritional compounds, such as β-glucan and polyphenol, which can be added to wheat flour to improve the dough nutritional quality. In this study, different formulated dough samples were obtained by individually adding four hulless barley flours into flour of a wheat variety (Jimai 44, designated as JM) which has very strong gluten. The effects of hulless barley supplementation on gluten structure, dough rheological properties, bread-making properties, and starch digestibility were assessed. The results showed that compared with JM dough, substitution of hulless barley flour to wheat flour at levels ranging from 10 to 40% negatively affected gluten micro-structure and dough mixing behavior, because the cross-links of gluten network were partially broken and the dough development time and stability time were shortened. For the hulless barley-supplemented bread, specific volume was significantly (P < 0.05) increased while springiness was not greatly changed. Furthermore, the hydrolysed starch rate in hulless barley-supplemented bread was decreased, compared with that in JM bread. Importantly, the contents of β-glucan, polyphenols and flavonoids in hulless barley-supplemented bread were 132.61–160.87%, 5.71–48.57%, and 25–293.75% higher than those in JM bread, respectively. Taken together, the hulless barley-supplemented bread has been fortified with enhanced nutritional components, more desirable bread-making quality, and improved starch hydrolytic properties, which shows a great potential to use hulless barley as a health supplement.

Assessment of the Starch-Amylolytic Complex of Rye Flours by Traditional Methods and Modern One

The properties of the starch-amylolytic complex of commercial low-extract rye flour were determined based on the traditional method, such as falling number and amylograph test as well as differential scanning calorimetry (DSC). The starch, pentosans and protein had a significant effect on the thermal properties of the tested rye flours. Based on the falling number, it was revealed that rye flours were characterized by medium and low alpha-amylase activity. The falling number and amylograph test are not sufficient methods to determine the suitability of currently produced rye flours for bread making. The gelatinization process of the rye flour starch could be evaluated by the DSC test, which, together with the falling number and amylograph test, may allow a better way to evaluate the usefulness of rye flours for bread making. Many significant correlations between parameters determined by DSC endotherm and quality parameters of rye bread, such as volume and crumb hardness, were reported. Breads made from flour with higher enthalpy in DSC were characterized by higher volume and softer crumb.