Oenological Characteristics of Four Non-Saccharomyces Yeast Strains With β-Glycosidase Activity

Non-Saccharomyces yeast with β-glucosidase activity might positively contribute to the flavor and quality of wines. The contribution of four non-Saccharomyces yeast strains Issatchenkia terricola SLY-4, Pichia kudriavzevii F2-24, P. kudriavzevii F2-16, and Metschnikowia pulcherrima HX-13 with β-glucosidase activity to the flavor and quality of wine making was studied. Compared with those of S. cerevisiae single fermentation, the four non-Saccharomyces yeast strains could grow and consume sugar completely with longer fermentation periods, and with no significantly negative effect on chemical characteristics of wines. Moreover, they produced lower content of C6 compounds, benzene derivative, and fatty acid ethyl ester compounds and higher content of terpene, β-ionone, higher alcohol, and acetate compounds. Different yeast strains produced different aroma compounds profiles. In general, the sensory evaluation score of adding non-Saccharomyces yeast-fermented wine was better than that of S. cerevisiae, and I. terricola SLY-4 fermentation received the highest one, followed by P. kudriavzevii F2-24, P. kudriavzevii F2-16, and M. pulcherrima HX-13 from high to low. The research results provide a theoretical basis for the breeding of non-Saccharomyces yeast and its application in wine making.

Fatty acid ethyl ester from Manilkara zapota seed oil: A completely renewable biofuel for sustainable development

This article reports the deliverables of the experimental study on the production of a completely renewable biofuel from Manilkara zapota fruit. It was attempted to produce fatty acid ethyl ester from Manilkara zapota seed oil using bioethanol synthesized from decayed Manilkara zapota fruit. Bioethanol was produced through fermentation of decayed Manilkara zapota fruit, waste skin, and pulp with Saccharomyces cerevisiae then extracted by distillation process at the temperature of 72°C. The bioethanol yield was noted as 10.45% (v/w). The purity of the bio-ethanol was identified as 95.09% using infrared spectroscopy and gas chromatography-mass spectrometry. Mechanically extracted Manilkara zapota seed oil was used for ethyl ester production. The molar ratio of bioethanol to oil, the quantity of KOH, and process temperature were optimized for the maximum yield of Manilkara zapota ethyl ester. 9:1 molar ratio of bioethanol to oil, 1.5% (w/w) KOH, and 70°C process temperature were identified as optimized ethanolysis process parameters. The maximum yield of ethyl ester was identified as 93.1%. Physicochemical characteristics of Manilkara zapota oil, bioethanol, and ethyl ester were measured as per the corresponding ASTM standards. It was found that both Manilkara Zapota ethyl ester and bioethanol synthesized from decayed Manilkara zapota fruit could be promising substitutes for fossil diesel and gasoline.

Extraction and study of Intracellular compounds of sedimentary wine yeast - waste product of wine production

The present work describes the results of research of a complex of substances obtained from sedimentary wine yeast by extraction with food extractants with the use of ultrasound. The filtrates of alcoholic extracts of yeast and sediments isolated from filtrate were investigated. It has been shown that hydrophobic substances moderately soluble and poorly soluble in alcohol, such as ethyl esters of fatty acids, fatty acids, phospholipids, sterols, squalene, were isolated from sedimentary wine yeast by extraction with alcohol-containing extractants. The mechanical effect of ultrasound provides faster and more complete penetration of the solvent into the intracellular substances. Ultrasound allows one to achieve greater penetration of the solvent into plant tissues and improve mass exchange. Ultrasonic waves, causing cavitation in the liquid, destroy cell walls and promote the release of cell matrix components. Thus, during the US treatment of suspended sedimentary wine yeast a mixture of fatty acid ethyl ester more than 2 times and squalene - 1.5 times, compared to the control, is observed.

Study on the derived based catalysts from Theobroma cacao pod husks for the conversion of beef tallow blend with waste used vegetable oil for fatty acid ethyl ester synthesis: burnt, submerged fermented, calcination, hybrid design, catalyst refining and reusability

Billions of dollars paid by industries on catalysts used as feedstocks to obtain their end products are increasing at a geometrical rate, the report revealed that the global marketplace price of catalysts stood at USD 26.1 billion in 2019, and is anticipated to increase by 4% in 2020, and 4.5% progress rate in 2025. To salvage the world from extravagance spending, there is an urgent need for biomass wastes consideration and utilization. In this paper, three novel CaO-based catalysts derived from Theobroma cacao pod husks were tested based on efficacy for the production of biodiesel (fatty acid ethyl ester: FAEE) from the blend of beef tallow oil (BTO)-waste used oil (WUO) in the ratio of 5:95 (BTO5),10:90 (BTO10),15:85 (BTO15), 20:80 (BTO20),….., 95:5 (BTO95), respectively. Process optimization of the transesterification reaction was carried out using a hybrid design to determine the effects of catalyst on the fatty acid ethyl ester (FAEE) yield. The efficiencies of the catalyst were tested via the refining and reusability test. Results revealed the oil blend ratio of BTO60: WUO40 sufficiently produced low viscous oil that was easily converted to biodiesel. Catalysts' characterization revealed the three catalysts produced high CaO-based of 68.20, 81.46, and 87.65 (wt.%), which accounted for the high yield of FAEEs. Mathematical optimization showed that the catalyst amount (F-value between 14159.69-3063.24 with P-value between 0.0053-0.0115), played the most significant role in oil conversion to biodiesel among the constraint factors considered (reaction time, catalyst amount, reaction temperature, and ethanol/oil molar ratio: EtOH/OMR). Based on Box-Cox transformation, the values of the lambda obtained indicated a normal data results with an inverse function of Y2 and Y3 and normal function of Y3 for polynomial model accuracy. Optimum validated FAEEs yields of 92.81, 93.02, and 99.64 (%wt.), respectively, with high R2. The qualities of the FAEEs were within the standard specification and the produced catalysts can serve as feedstocks for industrial application.