Optimization of Bioactive Compounds with Antioxidant Activity of Himanthalia elongata by Microwave-Assisted Extraction Using Response Surface Methodology

Himanthalia elongata is a brown alga used in applications in the food, pharmaceutical and nutraceutical industries due to its biological properties, such as antioxidant, anti-inflammatory, and antimicrobial, among others. These effects are attributed to the high content of nutrients and secondary metabolites, especially phenolic compounds. The objective of this study is to optimize the microwave-assisted extraction method to recover phenolic compounds and flavonoids, considering three extraction parameters: the concentration of ethanol in water, the extraction time and pressure. The total phenolic content and the total flavonoid content were evaluated, and two biological tests were performed to assess the antioxidant properties.

Temperature Dependent Solubility of Benzoic Acid in Aqueous Phase and Aqueous Mixtures of Aliphatic Alcohols

The benzoic acid solubility in aqueous phase and in various aqueous mixtures of methanol, ethanol and 2-propanol was determined at temperatures ranging from 303 to 333 K by an analytical technique. The results showed that the solubility of the acid in alcohols-water binary mixtures is high as compared to pure aqueous phase. The addition of alcohols to water favors the dissolution of benzoic acid which increases further with the increase in alcohols content of water within the investigated temperature range. The benzoic acid solubility in water alone and aqueous mixtures of the selected alcohols was in the order of; 2-propanol in water > ethanol in water > methanol in water > pure water. It is also observed that within the investigated temperature range, the acid solubility increases with rise in temperature in both the aqueous phase and alcohols-water binary solvents. The logarithm of the mole fraction of the acid’s solubility also showed a linear trend against the temperature. The experimental results obtained in the current study were compared with the reported literature for the studied acid and other organic acids in various solvents and showing a good agreement. The study will have implications in the processes involving separation, crystallization and pharmaceutical formulation in various industries.

Styrene Monomer Migration from Expanded Polystyrene Into Food Acids and Ethanol

Migration of styrene monomer from expanded polystyrene (EPS) at various time intervals (3 hr, 1, 2, 3, 5, 7, 9, 12, 18 days at 51OC) into nine different stimulants (water, 8% ethanol in water, 3% acetic acid, and 3 and 10% of food-grade citric, malic and tartaric acid) was determined using a modified FDA migration cell. Exposure to 8% ethanol resulted in the greatest average migration of styrene (147.6 µg/L) during 18 days of storage compared to all other stimulants tested. The concentration for styrene in 8% ethanol ranged from 49.3 to 228.5 µg/L over all exposure times. For all stimulants tested, styrene concentrations were greater than or equal to 22 µg/L after 3 hours of exposure. EPS exposed to malic (3 and 10%) and 10% tartaric acids had greater styrene migration than styrene exposed to all other acidic stimulants tested.

Biochemical Profile of Olive Leaves Grown in "Olive Valley" Pakistan

This study was designed to determine the best olive variety for cultivation in Pakistan. The leaves of eight locally grown varieties were analyzed for levels of moisture, total solids, ash, fat, fibre, protein, K, Ca, Mg, Na, Fe, Mn, Zn and Cu levels. Leaves were then subjected to solvent extraction with each of water ratio in, 75% ethanol, 75% methanol, 95% ethanol and 95% methanol. The extract yield was significantly highest for 75% ethanol extract of all varieties. Significantly highest polyphenol and flavonoid contents were examined for Gemlik leaves extracted with 75% ethanol. We recommend cultivation of Gemlik in Pakistan and extraction of bioactive compounds from olive leaves will be the most efficient with a binary solution of 75% ethanol in water. Further studies should be planned to assess antioxidant, antimicrobial and food preservation properties of olive leaf extract from locally grown varieties.

Comparative analysis of ethanol dynamics in aqueous and non-aqueous solutions

Dynamics of ethanol in water and in hexane across the whole concentration range is analyzed by molecular dynamics simulations.

Ethanol sprays to release grapevine bud dormancy: a potential alternative to cyanamides

Aim: Grape growers sometimes use cyanamides (calcium or hydrogen) to release bud dormancy in warm climate regions, where the chilling requirement has not been met during winter. However, these products can cause damage to plants and are dangerous to handle, so alternatives would be welcomed by growers. Connections between metabolisms of ethanol, ethylene and cyanide revealed by previous studies led us to test the potential of ethanol sprays on bud break and early shoot growth.Methods and results: Trials were performed over three years on Vitis vinifera grapevines trained in Guyot or cordon, and on cuttings in growth chambers. Cultivars used in the studies included Cabernet-Sauvignon, Syrah and Ugni blanc. The results show that ethanol can advance bud break of all three cultivars at concentrations ranging from 2.5 to 10 % ethanol in water. Ethanol stimulates bud development in both Guyot and cordon training systems. However, the timing of ethanol application is crucial, and late spring season applications reduce the effectiveness of the treatment.Conclusions: Observations were performed over three different seasons. The trials revealed that ethanol sprays can advance bud break of different Vitis vinifera vines, trained with cane or spur systems.Significance and impact of the study: Climate change impacts dormancy release, making it an increasingly important issue over the next few decades. An alternative to the dangerous use of cyanamides to promote bud break would greatly help growers. These preliminary results with ethanol are promising but should lead to trials in various growing areas and with various cultivars in order to confirm their potential for viticulture.

Direct Measurements of Small Polar Impurities in Gasoline Mixtures Using Molecular Rotational Resonance Spectroscopy

This paper reports our efforts to determine whether rotational spectroscopy is a useful tool for petroleum analysis. These efforts include the use of a BrightSpec molecular rotational resonance (MRR) spectrometer, which operates in the 260–290 GHz frequency range, to record rotational spectra of small polar contaminants in commercial gasoline. The observed rotational spectra showed rich, but assignable, patterns due to the sensitivity of the MRR to only small polar compounds. Any interference from a complex hydrocarbon matrix, which in conventional chromatographic methods obscures signals from small polar contaminants, is nearly eliminated. In addition to the evident rotational spectrum of ethanol, the spectra of toluene, ethyl cyanide, and acetaldehyde have also been detected. A quantitative method for ethanol has been developed and demonstrated in this paper, whereas the specific analyses of the other polar impurities will be reported in the future. The validity of MRR to be used as an analytical instrument has been examined by constructing a standard linear curve using dilutions of ethanol in water. The linearity and percentage recovery parameters are satisfactory.

DISPERSIBILITY OF NANOCRYSTALLINE CELLULOSE IN ORGANIC SOLVENTS

Aqueous suspensions of nanocrystalline cellulose (NCC) were obtained by sulfuric acid hydrolysis using the standard procedure. Suspensions, films and airgel of NCC were characterized by various methods: the degree of polymerization was determined, elemental analysis was carried out, the degree of crystallinity and crystallite size were calculated on the basis of X-ray data, the morphology of NCC aerogels was studied using scanning electron microscopy. The particle size of the NCC was determined using a transmission electron microscope, a scanning atomic-force microscope and the method of dynamic light scattering. NFC hydrosols with different pH were used to prepare lyophilized NCC samples. From NCC hydrosols with pH 2.2, by gradual replacement of water with an organic solvent, NCC organogels with acetone, acetonitrile and ethanol were obtained. The process of dispersion of lyophilized NCC and NCC organogels (acetone, acetonitrile and ethanol) in water and in 11 organic solvents was investigated. The effect of the pH of the initial aqueous suspension of the NCC and the solvent forming the NCC organogel on the repeated dispersibility of the NCC is shown. The optimum pH value of the initial aqueous suspension of NCC was determined, which determines the maximum dispersibility of the lyophilized samples in each specific solvent. It was shown that dispersion of acetone, acetonitrile and ethanol organogels in most of the solvents studied occurs with the formation of particles less than 100 nm.

Migration of Bisphenol A from Can Coatings into Beverages at the End of Shelf Life Compared to Regulated Test Conditions

Beverage cans are used for energy drinks, soft-drinks, sparkling waters, and beer. Bisphenol A is still part of the formulation of epoxy coatings of beverage cans. Due to concerns that bisphenol A acts as an endocrine-active substance, the migration of bisphenol A is restricted. Typically, the migration from beverage cans is tested at elevated temperatures into food simulants, like 20% ethanol in water. However, comparison tests of the migration of bisphenol A at the end of shelf life, with the migration into ethanolic food simulants, are not available in the scientific literature. The aim of the study was to determine the migration of the migration of bisphenol A into real beverages, compared to routine migration tests into the European official food simulant of 20% ethanol at 40 °C and 60 °C after storage for 10 days. As a result, bisphenol A-containing coatings show a considerably higher migration when tested at 60 °C in comparison to 40 °C. On the other hand, migration into energy drinks and coke, from the same coatings at the end of shelf life when stored at room temperature, was below the detection limit in either case. As expected, migration values of bisphenol A below the analytical detection limits were observed for any test conditions from the coating labeled bisphenol A-free. Spiking tests show that bisphenol A is stable in real beverages. Therefore, it can be concluded that the accelerated migration tests with 20% ethanol at the test conditions 10 d at 40 °C and 10 d at 60 °C significantly overestimate the real migration into beverages at the end of shelf life. This overestimation of the migration of bisphenol A is due to swelling of the epoxy can coating by the ethanolic food simulant. These findings were supported by migration modeling based on diffusion coefficients predicted for polyethylene terephthalate.