Isoamyl Alcohol Research Articles

Comparative Study on Nutritional Characteristics and Volatile Flavor Substances of Yak Milk in Different Regions of Gannan.

This study aimed to investigate the nutritional properties of yak milk in various areas of Gannan. The milk composition analyzer, automatic amino acid analyzer, and flavor analyzer were used to detect the conventional nutrients, amino acids, and volatile flavor substances of 249 yak milks in Meiren grassland, Xiahe grassland, and Maqu grassland (hereinafter referred to as Meiren yak, Xiahe yak, and Maqu yak) in the Gannan area. The results showed that the fat content of Meiren yak milk was significantly higher than that of Maqu yak and Xiahe yak (p < 0.05). The protein content of Meiren yak milk was significantly higher than that of Xiahe yak (p < 0.05), but not significantly different from that of Maqu yak (p > 0.05). The casein content in the milk of Maqu yak was significantly higher than that of Meiren yak and Xiahe yak (p < 0.05). There was no significant difference in the lactose content of yak milk in the three regions (p > 0.05). The content of glutamic acid in the milk of Meiren yak, Xiahe yak, and Maqu yak was noticeably high, which was 1.03 g/100 g, 1.07 g/100 g, and 1.10 g/100 g, respectively. The total amino acid (TAA) content was 4.78 g/100 g, 4.87 g/100 g, and 5.0 g/100 g, respectively. The ratios of essential amino acids (EAA) and total amino acids (TAA) in the milk of Meiren yak, Xiahe yak, and Maqu yak were 42.26%, 41.27%, and 41.39%, respectively, and the ratios of essential amino acids (EAA) and nonessential amino acids (NEAA) were 73.19%, 70.28%, and 70.61%, respectively. In the yak milk samples collected from three different regions, a total of 34 volatile flavor compounds were detected, including 10 aldehydes, five esters, six ketones, four alcohols, two acids, and seven others. The main flavor substances qualitatively obtained from Meiren yak milk were ethyl acetate, n-valeraldehyde, acetic acid, heptanal, and n-hexanal. Xiahe yak milk mainly contains ethyl acetate, isoamyl alcohol, n-valeraldehyde, heptanal, and ethyl butyrate. Maqu yak milk mainly contains ethyl acetate, n-valeraldehyde, isoamyl alcohol, heptanal, ethyl butyrate, and n-hexanal. Principal component analysis showed that the flavor difference between Xiahe yak and Maqu yak was small, while the flavor difference between Xiahe yak, Maqu yak, and Meiren yak was large. The findings of this research can serve as a foundation for the future advancement and application of yak milk.

Prevalence of Epstein-barr Virus (EBV) among Patients with Oral Squamous Cell Carcinoma from Ahvaz, Iran: A Case-Control Study

Epstein-Barr virus (EBV), one of the most significant causes of lymphoid and epithelial cancers, has been linked to oral carcinogenesis; however, this etiological association remains controversial. To investigate this association, the present study aimed to determine the prevalence of EBV in cancerous and non-cancerous oral tissues from Ahvaz, Iran. In total, 164 blocks of formalin-fixed paraffin-embedded tissues from oral squamous cell carcinoma (OSCC), including 76 tongue squamous cell carcinomas and 88 non-cancerous tongue tissues, were collected from Ahvaz Imam Khomeini Hospital, Ahvaz, Iran, from December 2014 to March 2019, for this case-control study. The tissues were cut into 15-μm-thick sections, and DNA was extracted using a solution of Phenol, Chloroform, and Isoamyl Alcohol. The EBV detection and typing were performed using nested polymerase chain reaction. The EBV was detected in 9 (5.48%) out of the 164 samples studied, including 4 (5.26%) of the 76 SCC cases and 5 (5.68%) of the 88 samples in the control group (P&gt;0.05). The EBV was positive in 2.40% of the 83 male and 8.6% of the 81 female samples (P&gt;0.05). In terms of the histological grades of the case group, 3 (3/57) and 1 (1/13) of the EBV-positive samples were well and moderately differentiated, respectively (P&gt;0.05). For EBV typing, the 9 EBV-positive samples were tested, and it was found that 2 and 7 of the cases were EBV type I and II, respectively. Results of the current study demonstrated the low frequency of EBV in Iranian patients with OSCC, with EBV type II predominating. Further studies are required to clarify the association between EBV and OSCC.

Enzymatic acylation of blueberry (Vaccinium ashei) pomace anthocyanins and determination of their cytotoxic properties

To expand the application of acylated blueberry pomace anthocyanins in food and nutraceuticals, their enzymatic acylation reaction and the cytotoxic response were explored. In this study, enzymatic acylation was carried out with cyanidin-3-O-glucoside (C3G) as the main body and Novozyme 435 as the biocatalyst. With a series of improvements, the reaction was carried out under the conditions of lauric acid as the acyl donor, tert-amyl alcohol as the reaction medium, the molar ratio of C3G to lauric acid of 1:10, the reaction time of 24 h and the reaction temperature of 60 °C, and 35.29 % acylation rate was obtained. Moreover, it was found that the lipophilicity, thermostability and photostability of the enzymatic acylated blueberry pomace anthocyanins were improved compared with the untreated blueberry pomace anthocyanins. Cytotoxicity studies showed that acylated blueberry pomace anthocyanins inhibited tumor cells (HeLa, HepG2, and B16 cells) significantly and were less toxic to normal cells (L929 cells) at the maximum concentration (1000 µg/mL) and the longest duration of action (72 h). This study established a method for acylation of blueberry pomace anthocyanins that may be applied to other natural sources of anthocyanins.

Does sensory quality assessed by beverage experts fit consumer acceptability? A study on cheongju

AbstractCheongju is traditional fermented liquor consisting of the filtered moieties of rice wine. In this study, the sensory quality of cheongjus judged by beverage experts (e.g., sommeliers) were compared with its acceptability. Total 166 consumers evaluated the acceptability of the cheongju samples, and 10 sommeliers appraised the sensory quality. Descriptive analysis was conducted by 11 trained panelists, and the volatile compounds were identified by gas chromatography–mass spectrometry. Partial least square regression was performed to establish the association of the quality scores given by sommeliers (Y1) and the acceptability scores given by consumers (Y2) relative to the cheongju's sensory attributes or volatile compounds (Xs). The consumer acceptability was highly correlated with sweet notes and related volatile compounds, such as isoamyl alcohol. Conversely, sensory quality by sommeliers was highly correlated with sensory notes caused by alcoholic compounds. These results demonstrate how consumers' acceptance for cheongju may differ from a sommelier's quality appraisal.Practical ApplicationsThis study reported differentiations between sommeliers' appraisals and consumers' preferences for evaluating cheongju in terms of volatile compounds and descriptive sensory attributes. Key sensory attributes and volatile compounds were provided for each sommelier's appraisal and for consumers' preferences for cheongju. Overall, this study provides objective information on the discrepancies between sensory quality and hedonic notions of traditional liquor. Future studies should elaborate on the sommelier effect through tasking informed condition, as sommeliers' recommendations may affect customers' choices and satisfaction.

Effect of multi‐step chaptalisation on physicochemical properties, potentially harmful alcohols, nutritional composition and volatile profiles of kiwi wine

SummaryChaptalisation is commonly used to ameliorate the potential alcohol of kiwi wine prior to fermentation. It can be performed either by one‐time sugaring or via multiple supplementations of sugar. However, for both approaches, their precise effects on chemical composition of kiwi wine are unclear. Thus, this study evaluated the influence of five different multi‐step chaptalisation strategies on physicochemical parameters, potentially harmful alcohols, nutritional composition and volatile compounds of kiwi wine. Results show that multi‐step chaptalisation significantly reduced total acidity and harmful alcohols of the resulting kiwi wine. Among the harmful alcohols, the greatest reduction was seen for isoamyl alcohol and isobutanol. Additionally, multi‐step chaptalisation also modified volatile profile of the kiwi wine, particularly in acetate esters (isoamyl acetate and phenethyl acetate), ethyl esters, n‐octanal and decanal. Together, our results highlight the potential of using multi‐step chaptalisation to produce ‘healthier’ kiwi wines with more balanced alcohol and more complexed flavour.

Identification and assessment of non-conventional yeasts in mixed fermentations for brewing bioflavored beer

The increasing demand for more flavored and complex beers encourages the investigation of novel and non-conventional yeasts with the ability to provide a combination of bioflavoring and low ethanol yields. The present study identified 22 yeasts isolated from different brewing sources, including the fermentation by-products known as yeast sludges, and characterized a selection of strains to find the more suitable for the aforementioned aims. HPLC and GC-FID analysis of its brewing products were performed.The most promising results were obtained with the non-conventional yeasts Pichia kudriavzevii MBELGA61 and Meyerozyma guilliermondii MUS122. The former, isolated from a Belgian wheat beer sludge, was capable of growing in wort (17.0°Bx., 20 °C) with very low ethanol yields (1.19 % v/v). Besides, upon mixed fermentations with Saccharomyces cerevisiae, was suitable to produce volatile compounds such as ethyl acetate, 2-phenyl ethanol and isoamyl alcohol, with characteristic fruity notes. M. guilliermondii MUS122, isolated from a golden ale beer sludge, partially attenuated the wort with low production of ethanol and biomass. In addition, provided some fruity and floral nuances to the aroma profile of mixed fermentations with brewer's yeast.The results suggest that these strains favor the development of more fruity-flowery aroma profiles in beers. Furthermore, they are suitable for use in mixed fermentations with Saccharomyces brewer's strains, although the ethanol level did not decrease significantly.

Spatial repellency and attractancy responses of some chemical lures against Aedes albopictus (Diptera: Culicidae) and Anopheles minimus (Diptera: Culicidae) using the high-throughput screening system.

We evaluated the behavioral responses of Aedes albopictus and Anopheles minimus to 3 isovaleric acid and lactic acid-based chemical lure blends and 2 individual alcohols, using Spatial Repellency Assay in a high-throughput screening system (HITSS). Five doses of 0.0002, 0.001, 0.0025, 0.005, and 0.01 g were tested per lure. A BG-lure was used as a reference standard. After 10-min exposure, the number of mosquitoes moving toward or away from the treated chamber was calculated. The results showed that all lures were repellent against Ae. albopictus except for Lure-4 (4% w/v isovaleric acid + 2% w/v lactic acid + 0.0025% w/v myristic acid + 2.5% w/v ammonium hydroxide) which showed a nonsignificant attractancy at the lowest dose. Significantly high spatial repellency was observed at the highest dose of all the tested lures including BG-lure. Lure-2 (isoamyl alcohol) was significantly repellent at all the tested doses. Against An. minimus, Lure-5 (0.02% w/v isovaleric acid + 2% w/v lactic acid) showed significant spatial repellency while Lure-4 was significantly attractant, at all the tested doses. All lures, except Lure-4, showed strong spatial repellency at high doses and attractancy or weak spatial repellency at the lowest dose of 0.0002 g. In summary, our study demonstrated that spatial repellency and attractancy of the tested lures were influenced by both the dose tested and the mosquito species. Lure-2 and Lure-4 are potential spatial repellents and attractants, respectively, for malaria and dengue vectors. However, further studies are necessary to confirm these results at a semifield and open field level.

Isolation, characterization, mathematical modeling and assessment of a novel Photobacterium sp. EAH3, as toxicity biosensor

Marine ecosystems are full of unique microbial phenomena, among them bioluminescence that could be harnessed for different ecological functions. This study was conducted to isolate luminous bacteria and utilize their glowing properties as a potential biosensor for toxicity assessment designs. It is worth noting that this study is the first report on the isolation of an Octopus associated Photobacterium species from Alexandria, Egypt. Based on light intensity, strain Photobacterium sp. EAH3 was selected and identified using 16S-rRNA gene sequencing. The luminescence production was further optimized using experimental. Among eight tested variables, the Plackett-Burman design showed that yeast extract, glycerol, peptone, and NaCl were the most important factors affecting luminescence. The central composite design calculated the optimum concentration of these variables in the optimized medium, which enhanced the bioluminescence activity by 1.39 folds. The employment of Photobacterium sp. EAH3 as a biosensor for the toxicity assessment of some solvents, hydrocarbons and heavy metals was examined using bioluminescence inhibition assay. According to the IC50 results, the highest toxicity values recorded were 0.004 M, 4.15 ppm and 1.4 ppm for isoamyl alcohol, Hg2+ and catechol, respectively. Moreover, our study sheds light on futuristic methodology for monitoring toxicity in real polluted environmental and effluents' samples reflecting its promising efficiency.

Influence of ethanol content on the detection of volatile components in Huangjiu

Huangjiu (Chinese rice wine) is a traditional Chinese fermented wine with a unique flavor. The components of this wine are complex, and the ethanol content of different Huangjiu preparations varies greatly. In this study, changes in the chromatographic peak areas of the volatile components of Huangjiu samples with different ethanol contents were measured using headspace-gas chromatography (HS-GC). The influence of ethanol on the quantitative detection of different volatile components of Huangjiu at gas-liquid equilibrium was also analyzed. When the ethanol content of Huangjiu was in the range of 10%-19% vol, the peak areas of 16 volatile components (i. e., sec-butanol, n-propanol, isobutanol, n-butanol, isoamyl alcohol, β-phenyl-ethanol, acetaldehyde, isovaleraldehyde, benzaldehyde, ethyl formate, ethyl acetate, isobutyl acetate, isoamyl acetate, ethyl hexanoate, ethyl lactate, and diethyl succinate) were negatively correlated with the ethanol content. Increases in the ethanol content of the liquor changed the gas-liquid equilibrium of most other trace volatile components. In addition, only the peak area of acetal was positively correlated with ethanol content. The content of acetal in Huangjiu was affected by the alcohol content, and its decomposition reaction occurred along with the dilution process. The influence coefficient of ethanol content on the peak area of the above compounds ranged from -12.4% to 4.9%. The vapor pressure of most volatile components decreased with increasing ethanol content, and different components were affected in different ways. Compared with those of other components, the peak areas of methanol, furfural, and acetic acid were less affected by the ethanol content. These components were also affected by other factors, such as ionization and chemical reactions occurring during the dilution process. When different wine samples were adjusted to the same ethanol content, the concentration of volatile components in these samples became proportional to the total chromatographic peak area and the influence of the matrix effect of ethanol on the quantitative analysis was effectively eliminated. Thus, when researchers use pretreatment methods based on the principle of gas-liquid balance to carry out the quantitative detection of flavor components, they should adjust different rice wine samples to the same alcohol content to effectively control the matrix effect caused by differences in ethanol content and achieve accurate quantitative analysis.

Characterization of Aroma Active Compound Production during Kombucha Fermentation: Towards the Control of Sensory Profiles.

Since the sensorial profile is the cornerstone for the development of kombucha as a beverage with mass market appeal, advanced analytical tools are needed to gain a better understanding of the kinetics of aromatic compounds during the fermentation process to control the sensory profiles of the drink. The kinetics of volatile organic compounds (VOCs) was determined using stir bar sorptive extraction-gas chromatography-mass spectrometry, and odor-active compounds were considered to estimate consumer perception. A total of 87 VOCs were detected in kombucha during the fermentation stages. The synthesis of mainly phenethyl alcohol and isoamyl alcohol probably by Saccharomyces genus led to ester formation. Moreover, the terpene synthesis occurring at the beginning of fermentation (Δ-3-carene, α-phellandrene, γ-terpinene, m- and p-cymene) could be related to yeast activity as well. Principal component analysis identified classes that allowed the major variability explanation, which are carboxylic acids, alcohols, and terpenes. The aromatic analysis accounted for 17 aroma-active compounds. These changes in the evolution of VOCs led to flavor variations: from citrus-floral-sweet notes (geraniol and linalool domination), and fermentation brought intense citrus-herbal-lavender-bergamot notes (α-farnesene). Finally, sweet-floral-bready-honey notes dominated the kombucha flavor (2-phenylethanol). As this study allowed to estimate kombucha sensory profiles, an insight for the development of new drinks by controlling the fermentation process was suggested. Such a methodology should allow a better control and optimization of their sensory profile, which could in turn lead to greater consumer acceptance.

Effects of Four Critical Gene Deletions in Saccharomyces cerevisiae on Fusel Alcohols during Red Wine Fermentation

Excessive fusel alcohols in red wine will bring an uncomfortable bitterness and generate an intoxicating effect, which affects the quality and attractivity of the red wine. In order to achieve better regulation of fusel alcohols in red wine, strains with LEU1 and PDC5 deletions were constructed, and seven engineered yeast strains based on THI3 and BAT2 deletions were applied to red wine fermentation to dissect the effects of four critical genes on fusel alcohols during wine fermentation. The fermentation results of these recombinant strains showed that the deletion of THI3 increased the contents of n-propanol, isobutanol, and isoamyl alcohol by 48.46%, 42.01%, and 7.84%, respectively; the deletion of BAT2 decreased isoamyl alcohol and isobutanol by 32.81% and 44.91%; the deletion of PDC5 and LEU1 decreased isoamyl alcohol by 40.21% and 68.28%, while increased isobutanol by 24.31% and 142%, respectively; the deletion of THI3 exerted a negative influence on the reduction of isoamyl alcohol caused by BAT2 or PDC5 deletion; the deletion of THI3 and PDC5 had a synergistic effect on the increase of isobutanol, while BAT2 and PDC5 deletion presented no additive property to the decrease of isoamyl alcohol. Hence, it is concluded that either BAT2, PDC5, or LEU1 deletion can effectively decrease fusel alcohols, especially isoamyl alcohol, which provides an important reference for the control of fusel alcohols in red wine.

A Novel Eco-Friendly Circular Approach to Comprehensive Utilizing Bittern Waste and Oyster Shell

Efficient waste management, especially in relation to swaste reuse, has become a pressing societal issue. The waste bittern generated during salt production and discarded oyster shells present formidable environmental challenges and a waste of resources for some coastal regions. Therefore, this work developed a two-stage circular process for the environmentally friendly and efficient utilization of both waste materials. In the first stage, CO2 gas and an organic extraction phase comprising Tri(octyl-decyl)amine (R3N) and isoamyl alcohol were introduced into the waste bittern to obtain MgCO3·3H2O (s). The second stage involved reacting the reacted organic extraction phase with oyster shell powders to produce CaCl2·2H2O (s) and CO2 (g) and regenerate R3N. This work focused on investigating the yield of MgCO3·3H2O and the regeneration ratio of R3N, which are crucial indicators for the two stages involved in the process. The results indicate that, under optimal operating conditions, a maximum yield of 87% for MgCO3·3H2O was achieved, and the regeneration ratio of R3N reached 97%. Furthermore, the reaction mechanism and thermodynamic functions of the R3N regeneration process were elucidated as a crucial element in achieving a circular process. The findings of this work offer a sustainable solution to environmental pollution from waste bittern and oyster shells, and provide a promising avenue for green chemical production.

Alternatives to classic solvents for the isolation of bioactive compounds from Chrysochromulina rotalis

This paper demonstrates a sequential partitioning method for isolating bioactive compounds from Chrysochromulina rotalis using a polarity gradient, replacing classic and hazardous solvents with greener alternatives. Seventeen solvents were evaluated based on their Hansen solubility parameters and for having a similar polarity to the solvents they would replace, four of which were selected as substitutes in the classic fractionation process. Considering the fatty acid and carotenoid recovery yields obtained for each of the solvents, it has been proposed to replace hexane (HEX), toluene (TOL), dichloromethane (DCM) and n-butanol (BUT) with cyclohexane, chlorobenzene, isobutyl acetate and isoamyl alcohol, respectively. In addition, cytotoxic activity was observed when the TOL and DCM solvent extracts were tested against tumour cell lines, demonstrating the antiproliferative potential of compounds containing, for example, fucoxanthin, fatty acids, peptides, isoflavonoids or terpenes, among others.

Introducing a Simple Method to Investigate Relative Volatilities of Flavour Compounds in Fruit Brandies

Determination of relative volatilities of flavour compounds in hydro-alcoholic solutions is usually performed by time-consuming and costly standard methods such as the Gillespie dynamic recirculation method. This study tested a quick and easy method with a simple distillation apparatus for measuring empirical relative volatilities. A total of 17 representative flavour compounds of apple and pear brandies were selected and investigated for their relative volatilities. This also included so far unpublished relative volatilities of one alcohol (2-butanol), one aldehyde (hexanal), one ketone (β-damascenone), and three esters (ethyl butyrate, butyl acetate, ethyl 2-methylbutyrate). Relative volatilities of three alcohols (methanol, isobutanol, and isoamyl alcohol), one ester (ethyl acetate), one aldehyde (acetaldehyde), and one acetal (1,1-diethoxyethane) were compared to reference data. All compounds, except for 1,1-diethoxyethane, showed a high correlation with the reference data. Vapour–liquid equilibrium for an ethanol–water mixture showed a high correlation with the reference data (r &gt; 0.9). In accordance with the high correlation levels, we suggest that the simple distillation apparatus is a fast and simple alternative to the standard method.

Brewing a Craft Belgian-Style Pale Ale Using Pichia kudriavzevii 4A as a Starter Culture.

There is an expanding market for beer of different flavors. This study aimed to prepare a craft Belgian-style pale ale with a non-Saccharomyces yeast. Pichia kudriavzevii 4A was used as a sole starter culture, and malted barley as the only substrate. The ingredients and brewing process were carefully monitored to ensure the quality and innocuousness of the beverage. During fermentation, the yeast consumed 89.7% of total sugars and produced 13.8% v/v of ethanol. The product was fermented and then aged for 8 days, adjusted to 5% v/v alcohol, and analyzed. There were no traces of mycotoxins, lead, arsenic, methanol, or microbiological contamination that would compromise consumer health. According to the physicochemical analysis, the final ethanol concentration (5.2% v/v) and other characteristics complied with national and international guidelines. The ethyl acetate and isoamyl alcohol present are known to confer sweet and fruity flavors. The sensory test defined the beverage as refreshing and as having an apple and pear flavor, a banana aroma, and a good level of bitterness. The judges preferred it over a commercial reference sample of Belgian-style pale ale made from S. cerevisiae. Hence, P. kudriavzevii 4A has the potential for use in the beer industry.

Secondary Amines from Catalytic Amination of Bio-Derived Phenolics over Pd/C and Rh/C: Effect of Operation Parameters

The production of renewable chemicals using lignocellulosic biomass has gained significant attention in green chemistry. Among biomass-derived chemicals, secondary amines have emerged as promising intermediates for synthetic applications. Here, we report a systematic study on the reductive amination of phenolics with cyclohexylamine using Pd/C and Rh/C as catalysts. The catalytic tests were performed in batch reactors under different reaction conditions (various: amine concentration (0.1–0.4 mol/L), hydrogen pressure (0–2.5 bar), temperature (80–160 °C), and substituted phenols (phenol, o-cresol, p-cresol, and methoxyphenol)) and using tert-amyl alcohol as a solvent. The experimental observations were consistent with a multi-step mechanism, where hydrogenation of phenol to cyclohexanone is followed by condensation of the ketone with cyclohexylamine to form an imine, which is finally hydrogenated to produce secondary amines. In addition, there was evidence of parallel self-condensation of the cyclohexylamine. The study also supported a limited dehydrogenation capacity of Rh/C, unlike Pd/C, which increases this capacity at higher temperatures generating a higher yield of cyclohexylaniline (up to 15%). The study of the alkylated phenols demonstrated that the nature and propensity of hydrogenation of the phenolic controls their amination. Kinetic analysis revealed reaction orders between 0.4 and 0.7 for H2, indicating its dissociative adsorption. Meanwhile, phenol’s order (between 1–1.8) suggests a single participation of this compound in the hydrogenation step. The order of 0.4 for cyclohexylamine suggests its participation as a surface-abundant species. The apparent activation energies derived from a power law approximation were of 37 kJ/mol and 10 kJ/mol on Pd/C and Rh/C, respectively.

Torulaspora delbrueckii Strain Behaviour within Different Refermentation Strategies for Sparkling Cider Production

Torulaspora delbrueckii is known for improving the aroma quality in wine and beer, but information for cider manufacturing is scarce. We explored the behaviour of two commercial strains of T. delbrueckii in apple juice fermentation to produce cider and sparkling cider. The influence of the strain, method, and strain–method interaction on the physicochemical parameters of cider was analysed by enzymatic and chromatographic assays. The data were subjected to an analysis of variance and a principal component analysis. Both strains also showed regular fermentation kinetics under pressure. Ethanol, lactic acid, acetic acid, and glycerol were produced with significant differences between strains and production methods. Then, 26 volatile compounds were identified, with higher alcohols being the quantitatively most abundant group. Strain A was associated with a higher production of methyl butanol, 2-phenyl ethanol, and butyric, propionic, and succinic acid esters, while strain B was associated with higher amounts of hexanoic acid, and acetate and valerate esters. In addition, 13 compounds showed significant differences between methods, and 14 were influenced by the method–strain interaction. Our findings encourage the further investigation of the application of T. delbrueckii as a solo player to produce ciders with a unique flavour.

A Lifetime of a Dispenser-Release Rates of Olive Fruit Fly-Associated Yeast Volatile Compounds and Their Influence on Olive Fruit Fly (Bactrocera oleae Rossi) Attraction

The objective of this study was to evaluate the release rate, duration, and biological efficiency of yeast volatile compounds associated with olive fruit flies in slow-release dispensers, polypropylene vials, and rubber septa attached to yellow sticky traps under different environmental conditions in order to protect the environment, humans, and nontarget organisms. Isoamyl alcohol, 2-octanone, and 2-phenethyl acetate were placed in dispensers and tested over a four-week experiment. The weight loss of the volatile compounds in both dispensers was measured, and a rapid, inexpensive, and simple HS-GC/FID method was developed to determine the residual amount of volatiles in the septa. 2-Phenethyl acetate stood out in the rubber septa and showed a statistically significant difference in the release ratio compared to the other volatiles under all conditions tested. Our results showed that the attraction of olive fruit flies increased with decreasing concentrations of the tested volatiles. Regarding the number of flies attracted by rubber septa containing 2-phenethyl acetate, significantly better results were obtained than for septa containing isoamyl alcohol and 2-octanone, in contrast to the attraction of olive fruit flies to polypropylene vials containing these compounds but without significant difference. Since the presence of all tested chemicals was detected during the experiment, this opens the possibility of using more environmentally friendly and cost-effective dispensers with a significantly lower amount of semiochemicals.

Synthesis and characterization of N-acyl alkanolamide surfactant from fatty acids and alcohol amines using sodium methoxide catalyst

Surfactant is a substance added to the liquid that improves the spread's properties by weakening the liquid's surface voltage. Surfactants have a molecular structure consisting of hydrophilic groups and hydrophobic groups. Surfactant needs in Indonesia continue to increase along with the development of industries in Indonesia. This study will be synthesized by the N-acyl surfactant alkanolamide using one type of alcohol amine, namely diethanolamine, through a reaction of amidation between fatty acids and using organic solvents tert-amyl alcohol. The catalyst used is a chemical catalyst, namely sodium methoxide. Furthermore, the purpose of this research is to determine the effect of reaction variables and determine the characteristics of the N-acyl alkanolamide surfactant in the form of acidic numbers and spreading numbers. This study showed for lauric acid, palmitate acid, and the best stearate acid at 90 oC reaction temperatures and 2-hour reaction times, while the best succinic acid at 100 oC and a reaction time of 2 hours. The relationship between reaction rate and time is directly proportional; the longer the reaction time, the higher the rate. The conversion relationship with reaction time is directly proportional, where conversion will increase with the increase in reaction time. However, this does not happen to all fatty acids. Due to the increase in reaction time, it will not provide significant results on surfactant products. The relation between the reaction temperature and the conversion acquisition at the time obtained decreased along with the increase in reaction temperatures. The acid numbers in the best conditions in a row are 40.67 for N-palmitoyl diethanolamine, 47.41 for N-lauroyl diethanolamine, 63.11 for N-succinyl diethanolamine, and 22.44 for N-stearoyl diethanolamine. The saponification number in the best conditions in a row is 36.47 for N-palmitoyl diethanolamine, 23.84 for N-lauroyl diethanolamine, 57.50 for N-succinoyl diethanolamine, and 7.01 for N-stearoyl diethanolamine.

Optimization of green and environmentally-benign synthesis of isoamyl acetate in the presence of ball-milled seashells by response surface methodology

Ball-milled seashells, as a nano-biocomposite catalyst and natural source of CaCO3 in its aragonite microcrystalline form with fixed CO2, was optimized for the synthesis of isoamyl acetate (3-methylbutyl ethanoate) by response surface methodology with a five-level three-factor rotatable circumscribed central composite design. The seashells nano-biocomposite has proved to be an excellent heterogeneous multifunctional catalyst for the green and environmentally-benign synthesis of isoamyl acetate from acetic acid and isoamyl alcohol under solvent-free conditions. A high yield of 91% was obtained under the following optimal conditions: molar ratio of alcohol: acetic acid (1:3.7), catalyst loading (15.7 mg), the reaction temperature (98 °C), and the reaction time (219 min). The outstanding advantages of this protocol are the use of an inexpensive, naturally occurring and easily prepared nano-biocomposite material having appropriate thermal stability and without any modifications using hazardous reagents, lower catalyst loading and reaction temperature, no use of corrosive Bronsted acids as well as toxic azeotropic solvents or water adsorbents, and simplicity of the procedure.