Ester Content Research Articles

Unlocking lager's flavour palette by metabolic engineering of Saccharomyces pastorianus for enhanced ethyl ester production

Despite being present in trace amounts, ethyl esters play a crucial role as flavour compounds in lager beer. In yeast, ethyl hexanoate, ethyl octanoate and ethyl decanoate, responsible for fruity and floral taste tones, are synthesized from the toxic medium chain acyl-CoA intermediates released by the fatty acid synthase complex during the fatty acid biosynthesis, as a protective mechanism. The aim of this study was to enhance the production of ethyl esters in the hybrid lager brewing yeast Saccharomyces pastorianus by improving the medium chain acyl-CoA precursor supply. Through CRISPR-Cas9-based genetic engineering, specific FAS1 and FAS2 genes harbouring mutations in domains of the fatty acid synthesis complex were overexpressed in a single and combinatorial approach. These mutations in the ScFAS genes led to specific overproduction of the respective ethyl esters: overexpression of ScFAS1I306A and ScFAS2G1250S significantly improved ethyl hexanoate production and ScFAS1R1834K boosted the ethyl octanoate production. Combinations of ScFAS1 mutant genes with ScFAS2G1250S greatly enhanced predictably the final ethyl ester concentrations in cultures grown on full malt wort, but also resulted in increased levels of free medium chain fatty acids causing alterations in flavour profiles. Finally, the elevated medium chain fatty acid pool was directed towards the ethyl esters by overexpressing the esterase ScEEB1. The genetically modified S. pastorianus strains were utilized in lager beer production, and the resulting beverage exhibited significantly altered flavour profiles, thereby greatly expanding the possibilities of the flavour palette of lager beers.

Effect of CaO/Fe2O3 Ratio and Oil/Methanol Molar Ratio on Biodiesel Production from Waste Cooking Oil

Biodiesel is a renewable liquid fuel that can be produced through the transesterification reaction of biomass. The objective of this research was to examine the effect of comparative composition of CaO and Fe2O3 on CaO/Fe2O3 catalysts from eggshells and Fe2O3 in the production of biodiesel from waste cooking oil. In addition, it was also studied the effect of the ratio of oil and methanol on the yield and characteristics of the biodiesel produced. Catalysts were prepared through impregnation. The esterification-transesterification process was carried out with the conditions WCO:methanol molar ratio of 1:3, 1:6, 1:9, 1:12 and 1:15, catalyst (3%wt oil), heated at 65°C for 3 hours with a stirring scale of 1200 rpm. The results showed biodiesel production using CaO: Fe2O3 catalyst with the ratio of CaO: Fe2O3 70:30 and WCO:methanol molar ratio of 1:9 obtained higher yield (84.5%) compared to others. The best biodiesel yield produced is the CaO:Fe2O3 catalyst ratio of 70:30 and the WCO:methanol molar ratio of 1:9 with a biodiesel yield of 84.50% with a methyl ester content of 99.63% and a FAME yield of 84.14%. The biodiesel produced has met the requirements of the Indonesian National Standard (SNI) in terms of density and viscosity.

Comprehensive analysis of flavor compounds and metabolites of vinasse hairtail fermentation based on GC-IMS and untargeted-based metabolomics

This study focused on investigating the degradation of proteins, metabolites, and flavors during the fermentation of vinasse hairtail, a local specialty fermented food in Zhoushan, China. The whole-protein SDS-PAGE results showed significant degradation of proteins, particularly actin and myosin. Total free amino acid content significantly increased, glutamate, leucine, alanine, and lysine were identified as the primary flavor amino acids conducive to the flavor, with umami, sweet, and bitter amino acids being predominant. The volatile constituents of the vinasse hairtail samples collected before fermentation (0 days) and after fermentation (8 days) were examined using gas chromatography-ion mobility spectrometry (GC-IMS). It revealed a total of 83 volatile flavor compounds, with the relative content of esters increasing and alcohols decreasing during fermentation. The untargeted metabolomics analysis identified 395 unique metabolites; the top 100 metabolites exhibited significant differences, including 52 oligopeptides, 18 organic acids and their derivatives, and 12 lipids and lipid molecules. The metabolic pathways involved in N-glycan biosynthesis, taurine and hypotaurine metabolism, pyrimidine metabolism, glycerophospholipid metabolism, alanine, aspartic acid, and glutamic acid metabolism, tricarboxylic acid cycle, and histidine metabolism. These pathways contribute to the generation of amino acids, sugars, organic acids, and other flavor compounds, ultimately influencing the evolution of the flavor of vinasse hairtail.

Study on the changes during the fermentation of the wine prepared from palm (Phoenix sylvestris) sap

The sugary sap of different palm trees is fermented to create palm wine, an alcoholic beverage. This work was aimed at studying the changes that occur during the fermentation process of wine made from the sap of the wild date palm species Phoenix sylvestris. At first, the best age of the palm tree was determined by observing total soluble solid and sap yield for 24 h and was found to be middle-aged palm plants (15–40 years old). Pure wine yeast (Saccharomyces cerevisiae SC22) and a natural starter culture were added to the palm saps, adjusting the total soluble solid (TSS) to 21.5° brix (°Bx). Total titratable acidity, pH, volatile acidity, reducing sugar, non-reducing sugar, total sugar, alcohol content, ester content, and aldehyde contents were the parameters under investigation. The statistical analysis showed significant (p ≤ 0.05) changes in the physico-chemical and volatile constituents of palm sap during the fermentation process in both systems. Sensory evaluation revealed that palm wine fermented with pure yeast culture was significantly superior to natural, spontaneously fermented wine. The acceptability test showed that the ideal characteristics of palm wine are cloudy in appearance, fruity in aroma, and sweet in taste.

Multi-omics analysis unravels chemical roadmap and genetic basis for peach fruit aroma improvement

Selection of fruits with enhanced health benefits and superior flavor is an important aspect of peach breeding. Understanding the genetic interplay between appearance and flavor chemicals remains a major challenge. We identify the most important volatiles contributing to consumer preferences for peach, thus establishing priorities for improving flavor quality. We quantify volatiles of a peach population consisting of 184 accessions and demonstrate major reductions in the important flavor volatiles linalool and Z-3-hexenyl acetate in red-fleshed accessions. We identify 474 functional gene regulatory networks (GRNs), among which GRN05 plays a crucial role in controlling both red flesh and volatile content through the NAM/ATAF1/2/CUC (NAC) transcription factor PpBL. Overexpressing PpBL results in reduced expression of PpNAC1, a positive regulator for Z-3-hexenyl acetate and linalool synthesis. Additionally, we identify haplotypes for three tandem PpAATs that are significantly correlated with reduced gene expression and ester content. We develop genetic resources for improvement of fruit quality.

Synergistic effect of La2O3-Al2O3 based catalysts for efficient biodiesel production

Comprehensive synergistic effect of La2O3-Al2O3 on the catalytic performance of transesterification reaction of palm oil with methanol for biodiesel production was studied. The prepared catalyst possessed bifunctional acid-base properties. The well-balanced of acido-basic sites amounts over the catalyst at the La2O3 loading of 40 % and the calcined temperature of 600 °C gave the maximum fatty acid methyl ester (FAME) content of 93.12 %, under the optimum conditions of 1:30 molar ratio of oil to methanol, 200 °C reaction temperature, 39 bar reaction pressure, 5 wt% catalyst loading and 5 h reaction time. The catalyst exhibited reasonable stability. The partial leaching of La3+ ions and deposition of organics resulted in the loss of activity. The results showed that the catalyst generated new weak basic sites and more effective in the transesterification compared to strong basic sites as reported previously. The different strengths of new acid sites were also formed. The balancing of acid-base sites amount was a key to control the catalytic activity and the formation of side reactions. This gives critical guidance in further catalyst development for biodiesel production of waste oils or low-quality oils via simultaneous esterification and transesterification, which helps the biodiesel system being economical and scalable.

Phthalates and fatty acid markers in free-ranging cetaceans from an insular oceanic region: Ecological niches as drivers of contamination

Plastic additives, such as phthalates, are ubiquitous contaminants that can have detrimental impacts on marine organisms and overall ecosystems' health. Valuable information about the status and resilience of marine ecosystems can be obtained through the monitoring of key indicator species, such as cetaceans. In this study, fatty acid profiles and phthalates were examined in blubber biopsies of free-ranging individuals from two delphinid species (short-finned pilot whale – Globicephala macrorhynchus, n = 45; common bottlenose dolphin – Tursiops truncatus, n = 39) off Madeira Island (NE Atlantic). This investigation aimed to explore the relations between trophic niches (epipelagic vs. mesopelagic), contamination levels, and the health status of individuals within different ecological and biological groups (defined by species, residency patterns and sex). Multivariate analysis of selected dietary fatty acids revealed a clear niche segregation between the two species. Di-n-butylphthalate (DBP), diethyl phthalate (DEP), and bis(2-ethylhexyl) phthalate (DEHP) were the most prevalent among the seven studied phthalates, with the highest concentration reached by DEHP in a bottlenose dolphin (4697.34 ± 113.45 ng/g). Phthalates esters (PAEs) concentration were higher in bottlenose dolphins (Mean ∑ PAEs: 947.56 ± 1558.34 ng/g) compared to pilot whales (Mean ∑ PAEs: 229.98 ± 158.86 ng/g). In bottlenose dolphins, DEHP was the predominant phthalate, whereas in pilot whales, DEP and DBP were more prevalent. Health markers suggested pilot whales might suffer from poorer physiological conditions than bottlenose dolphins, although high metabolic differences were seen between the two species. Phthalate levels showed no differences by ecological or biological groups, seasons, or years. This study is the first to assess the extent of plastic additive contamination in free-ranging cetaceans from a remote oceanic island system, underscoring the intricate relationship between ecological niches and contaminant exposure. Monitoring these chemicals and their potential impacts is vital to assess wild population health, inform conservation strategies, and protect critical species and habitats.

Physiological and Transcriptomic Analysis of Citrus Fruit Segment Drying under Facility-Forcing Cultivation

Facility-forcing cultivation could effectively improve the quality of ‘Beni Madonna’ citrus (Citrus nankao × C. amakusa) and advance the ripening period. However, segment drying (KS) before harvest caused fruit quality deterioration and commodity value loss. In this research, we investigated the physiological and molecular characteristics involved in citrus segment drying under facility-forcing cultivation. The juice yield, sugar, acid, vitamin C, and lignin contents in KS fruits were significantly decreased, and the contents of pectin and cellulose were significantly increased. The relative contents of abscisic acid and abscisic acid glucosyl ester in KS fruits were significantly decreased. A total of 1215 differentially expressed genes (DEGs) were screened by transcriptome sequencing. DEGs were significantly enriched in water metabolism, sugar metabolism, transportation, cell wall and phenylpropanoid biosynthesis, and plant hormone signal transduction. The decrease in water absorption and sugar synthesis, the increase of pectin and cellulose synthesis, and the decrease in ABA accumulation may be the main reasons that cause citrus fruit segments to dry under facility-forcing cultivation.

Correlation between the Characteristic Flavour and Microbial Community of Xuanwei Ham after Ripening

Xuanwei ham is a traditional fermented meat product in China with a unique production process and excellent-quality reputation at home and abroad. To reveal the microbial community succession of Xuanwei ham at different post-ripening times (W1-4) and its relationship with flavour formation, the microbial community, free amino acids, and volatile flavour compounds (VOCs) were analysed by high-throughput sequencing, liquid chromatography (LC), and gas chromatography–mass spectrometry (GC-MS), respectively. A total of 25 free amino acids were detected, among which W3 contained the fewest, and most were generally lower than in hams in the other three years. Fifty-nine VOCs were detected, among which 17 were esters, and the highest ester content was found in W4. Analysis of the bacterial community composition revealed that the bacterial community composition of ham samples from W3 and other years differed greatly, and at the gate level, the dominant bacterial group of Xuanwei ham from different years was Pseudomonadota. At the genus level, the most abundant genera in W1, W2, and W4 were all dominated by Sarocladium, Klebsiella, and Vibrio, with Klebsiella being the most abundant in W1. The most abundant genus in W3 was Vibrio, and the second most dominant genera were Sarocladium and Gammaretrovirus. In short, this study provides a theoretical basis for the storage, quality, and improvement of Xuanwei ham.

Compositional analysis of tuberose floral cuticle sheds light on scent volatile emission and cuticle deposition

The plant cuticle acts as a vital shield, safeguarding against environmental and biological stresses. Tuberose flowers, specifically the ‘Calcutta Single’ and ‘Calcutta Double’ cultivars of Agave amica (syn. Polianthes tuberosa), are highly prized in India for their aromatic and aesthetic appeal. This research examines the tuberose floral cuticle using GC-MS to identify key chemical components and their characteristics. The analysis uncovered six major chemical classes viz. fatty acids, fatty alcohols, esters, alkanes, alkenes, and aldehydes as the primary constituents of the cuticular wax. Fatty acids and fatty alcohols are dominant in both cultivars, with ‘Calcutta Single’ displaying a higher ester content than ‘Calcutta Double’. This study represents the inaugural in-depth exploration of cuticular wax in tuberose flowers, presenting a comparative investigation into these prominent cultivars.

The impact of simultaneous inoculation with Torulaspora delbrueckii and Hanseniaspora uvarum combined with Saccharomyces cerevisiae on chemical and sensory quality of Sauvignon blanc wines.

Non-Saccharomyces yeasts have great potential in improving wine quality, showing personality characteristics, and highlighting the terroir of wine. In this study, we evaluated the impact of simultaneous inoculation with the non-Saccharomyces yeasts Torulaspora delbrueckii or (and) Hanseniaspora uvarum in combination with Saccharomyces cerevisiae (EC1118 or VL3) on the aromatic compounds and sensory quality of Sauvignon blanc wines. The growth of yeast groups in the alcoholic fermentation process was tracked using fluorescence in situ hybridization. The presence of non-Saccharomyces yeast notably impacted the distribution of S. cerevisiae and was related to the species of yeast. The co-fermentation of H. uvarum and S. cerevisiae improved the content of total esters, especially acetate esters. Simultaneous inoculation of T. delbrueckii or (and) H. uvarum significantly increased the content of total terpenes, especially linalool. Similar results were found for some higher alcohols and organic acids. Sensory evaluation showed that the wines mixed fermentation with H. uvarum had significantly tropical fruit aroma characteristics. Citrus and mineral notes, typical aroma characteristics of Sauvignon blanc wine, were enhanced by mixed fermentation strategies with T. delbrueckii or (and) H. uvarum and different S. cerevisiae. Hence, co-fermentation by T. delbrueckii or H. uvarum combined with S. cerevisiae could significantly improve the sensory quality of Sauvignon blanc wine.

Pyrolysis characteristics of different types of tobacco and its correlation with the released aroma components under heating condition

An in-depth insight into the pyrolysis characteristics of tobacco is of great significance for the utilization of tobacco wastes. The effects of glycerol addition on the pyrolysis characteristics and distribution of aroma components of four types of tobacco was investigated in this study by using thermogravimetry and self-built rapid heating furnace capture and GC-MS analysis. Further, correlation network analysis was used to study the correlation between pyrolysis characteristics and released aroma components. It was found that the thermal weight loss behavior of different samples exhibited both commonalities and differences, the thermal weight loss process could be divided into four stages. After the application of glycerol, the overall performance of all types of tobacco leaves at stage II showed that DTGmax2 and WL2 increased, and glycerol had a relatively obvious effect on the pyrolysis characteristic parameters of flue-cured tobacco. Pyrolysis kinetic analysis based on Coats-Redfern method showed that the activation energy and pre-exponential factor of tobacco samples were decreased after the addition of glycerol. Under the heating condition, the total amount of released aroma components from each type of tobacco followed the order of burley tobacco > flue-cured tobacco >oriental tobacco > yellow sun-cured tobacco. The release amount of heterocyclic and olefins compounds from burley tobacco were higher, while flue-cured tobacco released higher contents of esters, ketones and furans compounds. The addition of glycerol promoted the release of aroma components. In terms of correlation, Tmax2 was negatively correlated with esters, aldehydes, and furans compounds, and positively correlated with DTGmax3. Tmax3 was significantly correlated with a lot of indicators, positively with acids, aldehydes, and furans compounds, but negatively with olefins and heterocyclic compounds.

The potential of catalyst based on palm leaves in biodiesel production as part of palm oil life cycle assesment

The advantages offered by biomass-based heterogeneous catalysts, such as being easily separated from reaction products, being used many times, having low production costs, and being widely available in nature. One of the heterogeneous catalysts that can be used is a sodium silicate catalyst, especially one obtained by impregnating Na metal on a SiO2 matrix derived from biomass ash. In this study, palm leaves have the potential to be used as raw material for the SiO2 matrix because their utilization has yet to be optimal. This research aims to synthesize, characterize, and apply a sodium silicate catalyst based on palm leaves ash in the production of biodiesel from Refined, Bleached, Deodorized, Palm Oil (RBDPO). SiO2 was obtained by calcining palm leaves at a temperature of 700 °C for 3 hours, followed by washing using 1 N HCl solution. In this research, variations in the mole ratio of NaOH: SiO2 were carried out in the synthesis of sodium silicate, namely 1:1, 1.5:1, 2:1, and 2.5:1. This research also evaluates the reusability of the sodium silicate catalyst and the effect of washing using methanol on the biodiesel yield produced. The best sodium silicate catalyst was obtained at a NaOH: SiO2 molar ratio of 1.5:1, with a biodiesel yield of 74.485 % and an ester content of 97.293 %. SEM analysis shows the presence of a porous structure on the catalyst. The existence of the Si-O-Na group has been confirmed using FTIR. BET-BJH analysis has confirmed the presence of a mesoporous structure in the catalyst, with a surface area of 6.4343 m2/g and a pore size of 5.3127 nm. The resulting sodium silicate catalyst can be used up to three times, with a yield of 62.388 %. Catalyst regeneration using methanol is capable of producing biodiesel with a yield of 45.198 %

Transcriptomic and Physiological Analysis Reveals the Possible Mechanism of Inhibiting Strawberry Aroma Changes by Ultrasound after Harvest.

The volatile compounds in strawberries play a significant role in the formation of strawberry aroma. However, these compounds undergo continual changes during storage, resulting in a decline in quality. In this study, a total of 67 volatile organic compounds (VOCs) were identified in strawberries through quantitative analysis. At the end of the storage period, the VOC content in the ultrasonic group was 119.02 µg/kg higher than that in the control group. The results demonstrated that the ultrasonic treatment increased the contents of terpenes and esters at the end of storage. Among these, linalool increased from 67.09 to 91.41 µg/kg, while ethyl cinnamate increased from 92.22 to 106.79 µg/kg. Additionally, the expression of the key metabolic genes closely related to these substances was significantly up-regulated. The expression of the FaNES gene, related to terpene metabolism, was up-regulated by 2.8 times in the second day, while the expression of the FaAAT gene, related to ester metabolism, was up-regulated by 1.5 times. In summary, this study provides a theoretical basis for exploring the mechanism of ultrasonic effect on strawberry flavor and quality after harvest.

Does Microbiome Matter in Chronic Intestinal Failure Due to Type 1 Short Bowel Syndrome in Adults?

The exact microbiome composition and function of patients with Short Bowel Syndrome (SBS) and Chronic Intestinal Failure (CIF) are still unknown. Patients with type I SBS-CIF (end-jejunostomy/ileostomy) are little represented in available studies. The aim of this study is to evaluate the microbiome characteristics of adult type 1 SBS-CIF patients according to their clinical features. Fecal microbiota was studied by amplicon-based sequencing and volatile organic compounds (VOCs) were assessed by solid-phase microextraction and gas chromatography-mass spectrometry. A total of 44 adult type 1 SBS-CIF patients were enrolled. At the family level, Lactobacillaceae (38% of the relative frequency) and Streptococcaceae (24%) were predominant; at the genus level, Streptococcus (38% of the relative frequency) and Lactobacillus (24%) were the dominant amplicon sequence variants (ASVs). Patients with increased stomal output showed higher ASVs for Lactobacillus (Rho = +0.38; p = 0.010), which was confirmed after adjusting for small bowel length (OR = 1.04; 95% CI 1.01-1.07, p = 0.023). Hyperphagia was associated with higher concentrations of short-chain fatty acid (SCFA) esters, such as butanoic acid ethyl ester (p = 0.005) and hexanoic acid ethyl ester (p = 0.004). Dietary fiber intake was directly correlated with most VOCs. Hyperphagia was associated with dietary fiber, after adjusting for small bowel length (OR = 1.35; 95% CI 1.01-1.81; p = 0.040). In type 1 SBS-CIF patients, a greater frequency of Lactobacilli was associated with increased stomal outputs, while increased fiber intake and concentrations of SCFA esters were associated with hyperphagia. These results might have implications for clinical practice.

A Facile LC-MS Method for Profiling Cholesterol and Cholesteryl Esters in Mammalian Cells and Tissues.

Cholesterol is central to mammalian lipid metabolism and serves many critical functions in the regulation of diverse physiological processes. Dysregulation in cholesterol metabolism is causally linked to numerous human diseases, and therefore, in vivo, the concentrations and flux of cholesterol and cholesteryl esters (fatty acid esters of cholesterol) are tightly regulated. While mass spectrometry has been an analytical method of choice for detecting cholesterol and cholesteryl esters in biological samples, the hydrophobicity, chemically inert nature, and poor ionization of these neutral lipids have often proved a challenge in developing lipidomics compatible liquid chromatography-mass spectrometry (LC-MS) methods to study them. To overcome this problem, here, we report a reverse-phase LC-MS method that is compatible with existing high-throughput lipidomics strategies and capable of identifying and quantifying cholesterol and cholesteryl esters from mammalian cells and tissues. Using this sensitive yet robust LC-MS method, we profiled different mammalian cell lines and tissues and provide a comprehensive picture of cholesterol and cholesteryl esters content in them. Specifically, among cholesteryl esters, we find that mammalian cells and tissues largely possess monounsaturated and polyunsaturated variants. Taken together, our lipidomics compatible LC-MS method to study this lipid class opens new avenues in understanding systemic and tissue-level cholesterol metabolism under various physiological conditions.

Effect of cultures of synthetic starters on the flavour and ethyl carbamate content of rice wine

SummaryEthyl carbamate (EC) concentration is an important indicator of the safety of rice wine. In this study, the effects of replacing traditional starters with synthetic starters on the quality of rice wine were studied to provide a basis for the application of laboratory strains to explore the metabolic basis of EC formation in rice wine fermentation systems. The effects of synthetic starters on the physicochemical indices, free amino acids, flavour compounds, urea and EC of rice wine were studied. The results showed that the microorganism species and inoculation fermentation method strongly influenced the physicochemical and flavour properties of the rice wine, among which continuous co‐fermentation improved the mellowness and flavour of the rice wine. The concentrations of urea and EC in rice wine fermented with synthetic starters decreased significantly compared with those in the control group, in which the urea content decreased by up to 97.4% and the EC content decreased by up to 90.9%. In addition, the flavour compound data showed that the differences in the aromas of rice wine fermented with different starters were mainly due to the differences in the contents of alcohols and esters. These findings suggest that EC can be regulated by changes in starters and provide guidance for the optimal configuration of mixed fermentation systems.

A contemporary view of the mechanisms of formation of new contaminants in vegetable oils – esters of monochloropropanediols and high molecular weight carboxylic acids

Monochloropropanediols (MCPD) and their esters with high molecular weight carboxylic (fatty) acids are new types of technological contaminants present in refined deodorized oils and other foods.The development of measures to minimize the content of MCPD esters in vegetable oils, which are an important component of various food systems, is a priority direction of modern foreign and domestic research in the field of ensuring food safety. The effectiveness of such measures should be based on ideas about the mechanisms of formation of MCPD esters and the identification of their predecessors (precursors) present in the lipid complex of oil seeds, as well as those formed during their processing.Systematized statistically reliable scientific knowledge about the mechanisms of formation of MCPD esters and their derivatives is still missing. Presumably, the formation of MCPDs and their esters with fatty acids should correlate with the presence of chlorine compounds in oilseed raw materials and in the oil itself; chlorine-containing pesticides and biologically active substances (fertilizers) used in agricultural production are one of the sources.Thus, the goal of the research is a systematic and comprehensive synthesis of ideas about precursors and mechanisms of formation of MCPD esters.As a result of analysis and synthesis of literature sources, it has been established that the main precursors of MCPD esters are DAG, TAG and various chlorine-containing compounds. The main factors influencing the rate of formation and amount of accumulation of MCPD esters are high temperatures (more than 120°C), duration of heat treatment, the presence of free fatty acids, antioxidants and moisture. Different chlorine compounds appear to have different activities in the reactions leading to the formation of MCPD esters. The presence of antioxidants in lipid systems can inhibit the formation of 3-MCPD ester, and the effectiveness of the process is determined by the type of antioxidant. According to the degree of increase in inhibitory ability, the most applicable antioxidants in lipid systems can be ranked as follows: α-tocopherol, BOA, BOT, AP, PG and TBHQ. The role of the composition of fatty acids in the formation of MCPD esters still remains unclear; however, there is indirect evidence indicating the influence of the composition of fatty acids on the level of accumulation of MCPD esters, which determines the feasibility of an in-depth study of this issue.

An experimental design approach to modeling water-free foams

In order to create more eco-friendly products, the industry (such as cosmetics) needs to reduce water consumption, not only in the processing stages but also in the composition of the products themselves. However, water-free products remain challenging, especially in terms of formulation. This paper presents an experimental design approach to model the structure-function properties of natural, biodegradable, and water-free oil foams stabilized with a sucrose ester. In particular, the effects of the sucrose ester concentration and foam-whipping time on foams’ bubble size, size distribution, over-run, and firmness were studied. Also, through surface tension measurements, the bubbles’ surface coverage by the sucrose esters was calculated. In addition, oil/sucrose ester mixtures were prepared at varying mixing temperatures (70, 80, 90, 100 °C) and mixing time durations (1, 5, 24, 72 h) and then whipped causing a direct effect on the foams’ physical properties. The resulting water-free foams had high over-runs (up to 74 %) with a stability of more than 5 months at 25 °C.

Tissue-Specific Accumulation Profiles of Phorbol Esters in Response to Abiotic and Biotic Stresses in Jatropha curcas

Jatropha curcas L. (J. curcas), a shrub plant of the Euphorbiaceae family, has received enormous attention as a promising biofuel plant for the production of biodiesel and medical potential in ethnopharmacology. However, the tumor-promoter toxin phorbol esters present in J. curcas raise concerns for health and environmental risk as its large-scale cultivation limits the use of meal obtained after oil extraction for animal feed. Here, we determined the variation of phorbol ester profiles and contents in eight J. curcas tissues by high-performance liquid chromatography (HPLC) and found phorbol esters present in all parts of the plant except the seed shell. We showed tissue-specific patterns of accumulation of phorbol esters and associated terpenoids at the transcriptional level with high transcript levels in reproductive and young tissues. Genes involved in the same module of terpenoids biosynthesis were positively correlated. We further present diverse abiotic and biotic stresses that had different effects on the accumulation of transcripts in terpenoids shared and branched terpenoid pathways in plant seedlings. The fine-tuning of terpenoids biosynthesis may link with ecological functions in plants under extreme environments and defense against pathogens.