Characteristics of gelatin from lizardfish (Saurida micropectoralis) and threadfin bream (Nemipterus hexodon) skins as influenced by extraction conditions.

Gelatins from lizardfish and threadfin bream skins were extracted using distilled water at 45 and 60 °C and 4, 8 and 12 h. Gelatin recovered from both lizardfish and threadfin bream skins was in the range of 63.96-91.46%. As extraction temperature and duration increased, the turbidity of gelatin solution from both species increased. Gelatins isolated from either lizardfish or threadfin bream skins at 45 °C for 4 and 8 h showed the maximum bloom strength (245.03-320.85 g), which were also greater than commercial gelatin from bovine (208.55 g) (P < 0.05). The gelatin gels (6.67%, w/v) could set at 4 °C within 3 min and were able to set at room temperatures within 51.83 min. Gelatins extracted from both fish skins contained α1-, ß- and γ-chains as predominant protein components. The lightness of all gelatin gels faintly declined with an increase in extraction temperature and time. Among the various production conditions explored, lizardfish/threadfin bream skin gelatin developed at 45 °C and 8 h was found to be highly comparable to commercial bovine gelatin. Based on the results obtained, gelatin from both fish species could be used as a replacement for land animal counterparts and can be used in many different food and pharmaceutical products.

Impact of different extraction conditions on yield, physicochemical and functional characteristics of gelatin from Labeo rohita swim bladder.

Influences of different extraction temperatures (50, 60, and 70 °C) and time (3, 6, and 9 h) on yield, physicochemical, and functional properties of gelatin from swim bladder (SBG) of rohu (Labeo rohita) were investigated. Gelatin extracted at 60 °C (G60-9 h), and 70 °C (G70-9 h) temperature for 9 h showed highest gelatin yield 54.91 g/100 g, protein (92.35 g/100 g), and hydroxyproline (77.50 mg/g) content (P < 0.05) compared to other counterparts. All extracted gelatin showed major protein components as α-, ß-, and γ-chain with slight changes in band intensity. FTIR spectra showed significant loss of molecular order of triple-helix as temperature and time increased. Furthermore, G60-9 h exhibited higher emulsion, foaming, and gel strength than G70-9 h, and G50-9 h, respectively (P < 0.05). Therefore, G60-9 h could be appropriate conditions for the extraction of SBG with better yield, physicochemical, and functional properties.

A Comparative Study of the Antihypertensive and Cardioprotective Potentials of Hot and Cold Aqueous Extracts of Hibiscus sabdariffa L. in Relation to Their Metabolic Profiles.

Ethnopharmacological relevance: Since ancient times, Hibiscus sabdariffa L. calyces have been used as a folk remedy for the treatment of hypertension. However, it is questionable as to whether there is a difference in the antihypertensive activity of the hot or cold aqueous extracts. Aim of the study: We designed this study to specify the best method for water extraction of the antihypertensive metabolites of H. sabdariffa and to confirm their in vivo antihypertensive capabilities. Materials and methods: The powdered dried calyces of H. sabdariffa were independently extracted with cold and hot water. A comparative study was performed between the cold and hot aqueous extracts of H. sabdariffa based on evaluation of the in vitro renin and angiotensin-converting enzyme (ACE) inhibition activities. Additionally, both extracts were subjected to an in vivo study for the evaluation of their antihypertensive activities in L-Nw-Nitro arginine methyl ester (L-NAME)-induced hypertensive rats. Further, a metabolomics study was also performed for both extracts to identify their chemical constituents. Results: The cold and hot extracts significantly reduced the angiotensin II, ACE, and aldosterone levels in the plasma. Furthermore, in the myocardium and aorta, decreased iNOS (inducible nitric oxide synthase) levels and elevated eNOS (endothelial nitric oxide synthase), as well as the rise in plasma NO levels, were reported with both extracts, but better results were displayed with the hot extract, leading to a potential antihypertensive effect. Additionally, the cold and hot Hibiscus extracts induced a cardioprotective effect through reducing necrosis, inflammation, and vacuolization that results from the induction of hypertension, an effect that was more prominent with the hot extract. Moreover, a comprehensive metabolomics approach using ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was able to trace the metabolites in each extraction. Conclusion: The extracts showed different anthocyanin and phenolic compounds, but the hot extract showed higher contents of specific phenolics to which the superior antihypertensive and cardioprotective activities could be related.

Elucidating the combined effect of sample preparation and solid-phase microextraction conditions on the volatile composition of cooked meat analyzed by capillary gas chromatography coupled with mass spectrometry.

Solid-phase microextraction coupled to gas chromatography-mass spectrometry is a common approach to analyze the volatile profile of cooked meat. The present study aims to investigate the combined effect of sample preparation, including meat presentation (minced and steak) and cooking method (stewed and grilled), and extraction temperature (30, 60 and 80 °C) and time (30 and 50 min) on the volatile composition of cooked deer meat. The statistical results indicated that extraction temperature was the most relevant factor affecting the meat volatile profile of cooked meat followed by the extraction time. Higher extraction temperatures improved the detection of heavy volatile compounds, while sample preparation had little influence on the meat volatile profile, probably due to the accurate control of the parameters used for meat presentation and cooking methods. The results of this work can assist in the standardization of analytical procedures for the characterization of volatile compounds in cooked meat.

Metabolic Profiling-Based Evaluation of the Fermentative Behavior of Aspergillus oryzae and Bacillus subtilis for Soybean Residues Treated at Different Temperatures.

Soybean processing, e.g., by soaking, heating, and fermentation, typically results in diverse metabolic changes. Herein, multivariate analysis-based metabolic profiling was employed to investigate the effects of fermentation by Aspergillus oryzae or Bacillus subtilis on soybean substrates extracted at 4, 25, or 55 °C. As metabolic changes for both A. oryzae and B. subtilis were most pronounced for substrates extracted at 55 °C, this temperature was selected to compare the two microbial fermentation strategies, which were shown to be markedly different. Specifically, fermentation by A. oryzae increased the levels of most organic acids, γ-aminobutyric acid, and glutamine, which were ascribed to carbohydrate metabolism and conversion of glutamic acid into GABA and glutamine. In contrast, fermentation by B. subtilis increased the levels of most amino acids and isoflavones, which indicated the high activity of proteases and ß-glucosidase. Overall, the obtained results were concluded to be useful for the optimization of processing steps in terms of nutritional preferences.

Effect of extraction temperature on rheological behavior and antioxidant capacity of flaxseed gum.

Soluble flaxseed gum (SFG) extracted at different temperatures (25, 40, and 60 °C) was analyzed in relation to the yield, polysaccharides and phenolics composition, surface charge, color, and rheological properties. The yield of SFG extract increased as the extraction temperature increased. The SFG xylan was the main component regardless the extraction temperature, but a reduction of substituents on the xylose chain was observed when increasing the extraction temperature. The phenolic compounds were also affected by the extraction temperature, influencing the antioxidant capacity of the gum. For all the extraction temperatures, SFG aqueous solutions showed a shear time-independent and shear-thinning behavior. Furthermore, oscillatory measurements showed a prevailing viscous character, but the decrease of the extraction temperature resulted in an increase of both G' and G". Therefore, SFG extracted at low extraction temperatures showed higher viscous and elastic properties, while high extraction temperatures increased the antioxidant activity.

Effects of Different Temperatures on the Chemical Structure and Antitumor Activities of Polysaccharides from Cordyceps militaris.

The effects of different extraction temperatures (4 and 80 °C) on the physicochemical properties and antitumor activity of water soluble polysaccharides (CMPs-4 and CMPs-80) from Cordyceps militaris (C. militaris) were evaluated in this study. The results of gas chromatography (GC) and high-performance gel permeation chromatography (HPGPC) showed that a higher extraction temperature could degrade the polysaccharides with 188 kDa, mainly composed of glucose, and increase the dissolution rate of polysaccharides about 308 kDa, mainly consisting of rhamnose and galactose. In addition, the CMPs displayed the same sugar ring and category of glycosidic linkage based on Fourier-transform infrared spectroscopy (FTIR) analysis, however, their invisible structural difference occurred in the specific rotation and conformational characteristics according to the results of specific optical rotation measurement and Congo red test. In vitro antitumor experiments indicated that CMPs-4 possessed stronger inhibitory effects on human esophagus cancer Eca-109 cells by inducing cell apoptosis more than CMPs-80 did. These findings demonstrated that the polysaccharides extracted with cold water (4 °C) could be applied as a novel alternative chemotherapeutic agent or dietary supplement with its underlying antitumor property.

Effects of time and extraction temperature on phenolic composition and functional properties of red rooibos (Aspalathus linearis).

This work was aimed at assessing the time-temperature effects on the phenolic compounds and in vitro functional properties of aqueous extracts from red rooibos (Aspalathus linearis). The major phenolic composition (tannins, flavonoids, flavonols, ortho-diphenols, total phenolic content), antioxidant (ABTS and DPPH) and reducing capacities (FRAP and total reducing capacity), antimicrobial effects and inhibition of α-amylase/α-glucosidase were measured. Phenolic compounds were also determined by LC-ESI-MS/MS. Aqueous extracts did not inhibit the growth of Escherichia coli, Staphylococcus aureus, and Candida albicans between 7.81 and 1000mgL-1. Rooibos extracted at 85°C for 10min showed a beneficial interaction with the human erythrocytes, reducing the hemolysis. The correlation analysis showed that the phenolic compounds responsible for the inhibition of α-amylase (IC50) were isohrmanetin, isoquercitrin, luteolin, salicylic acid, and syringaldehyde, whereas the inhibition of α-glucosidase was correlated to syringaldehyde, isoquercitrin, and luteolin. Overall, rooibos extracted at 85°C had the highest antioxidant activity measured by all assays, higher contents of phenolic compounds (spectrophotometric and LC-ESI-MS/MS data), and lower IC50 values for the digestive enzymes. On the other hand, rooibos extracted at 65°C had the opposite behavior, while rooibos extracted at 75°C presented mean intermediate values for the responses. This result clearly indicates that the extraction temperature is the main factor leading to a higher extraction of bioactive compounds from red rooibos.

Properties of gelatin film from horse mackerel (Trachurus japonicus) scale.

Optimal conditions for extracting gelatin and preparing gelatin film from horse mackerel scale, such as extraction temperature and time, as well as the protein concentration of film-forming solutions were investigated. Yields of extracted gelatin at 70 °C, 80 °C, and 90 °C for 15 min to 3 h were 1.08% to 3.45%, depending on the extraction conditions. Among the various extraction times and temperatures, the film from gelatin extracted at 70 °C for 1 h showed the highest tensile strength and elongation at break. Horse mackerel scale gelatin film showed the greatly low water vapor permeability (WVP) compared with mammalian or fish gelatin films, maybe due to its containing a slightly higher level of hydrophobic amino acids (total 653 residues per 1000 residues) than that of mammalian, cold-water fish and warm-water fish gelatins. Gelatin films from different preparation conditions showed excellent UV barrier properties at wavelength of 200 nm, although the films were transparent at visible wavelength. As a consequence, it can be suggested that gelatin film from horse mackerel scale extracted at 70 °C for 1 h can be applied to food packaging material due to its lowest WVP value and excellent UV barrier properties.

Quantification of caffeine, trigonelline and nicotinic acid in espresso coffee: the influence of espresso machines and coffee cultivars.

Caffeine, trigonelline and nicotinic acid are important bioactive constituents of coffee. In this work, the combination of different water temperatures and pressures in the settings of the espresso coffee (EC) machine was evaluated, to assess how these factors influence how effectively caffeine, trigonelline and nicotinic acid are extracted from both Arabica and Robusta samples. The proposed analytical method, based on a high performance liquid chromatography (HPLC) system coupled to a variable wavelength detector (VWD), showed good linearity (R²> 0.9985) and good recoveries (71-92%); after validation for three monitored compounds, the method was used to analyze 20 commercial samples. The combination of a temperature of 92 °C and pressure at 7 or 9 bar seems to be the ideal setting for the most efficient extraction of these compounds and consequently for their intake; the compound extracted in the greatest quantity was caffeine, which was in the range of 116.87-199.68 mg in a 25 ml cup of coffee.

Antioxidant activity and free radical-scavenging capacity of Gynura divaricata leaf extracts at different temperatures.

BACKGROUND: Extraction temperature influences the total phenolic content (TPC), total flavonoid content (TFC) of medicinal plant extracts to a great extend. TPC and TFC are the principle activity constituents present in the plant. The effects of extraction temperature on TPC, TFC and free radical-scavenging capacity of Gynura divaricata leaf extracts are worth to study. MATERIALS AND METHODS: Folin-Ciocalteu and aluminum chloride colorimetric assay were used to determine the TPC and TFC of Gynura divaricata leaf extracts at different temperatures. The antioxidant and free radical-scavenging activity were measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and phosphomolybdenum methods. RESULTS: TPC and TFC were significantly elevated with increasing extraction temperature (from 40°C to 100°C). However, TPC and TFC were not significantly different (P > 0.05) at the extraction temperatures 90°C and 100°C. Also, the extracts obtained at a higher temperature exhibited a significant free radical-scavenging activity compared with extraction at lower temperatures (P < 0.05). The TPCs (13.95-36.68 mg gallic acid equivalent/g dry material) were highly correlated with DPPH (R(2) = 0.9229), ABTS (R(2) = 0.9951) free radical-scavenging capacity, and total antioxidant activity (R(2) = 0.9872) evaluated by phosphomolybdenum method. CONCLUSION: The TPC and TFC of G. divaricata leaf was significantly influenced by the extraction temperatures, which were the main antioxidant constituents present in the G. divaricata plant.

Fatores que influenciam a reação de saponificação dos carotenóides presentes no urucum (Bixa orellana L. ) / Factors that influence saponification reaction in annatto (Bixa orellana L. ) carotenoids

Conduziu-se este trabalho, com o objetivo de estudar o efeito de diferentes concentrações de KOH (0,6 por cento, 1 por cento, 2 por cento, 3 por cento, 4 por cento e 5 por cento) e temperatura de extração (25ºC, 50°C, 60°C e 70°C) na reação de saponificação dos principais pigmentos de urucum. O progresso da reação foi acompanhado pela quantificação do teor de bixina e de norbixina por meio de cromatografia líquida de alta eficiência (CLAE). A maior concentração de base propiciou a maior conversão de bixina em norbixina (KOH 5 por cento - bixina: 0,44 g.100g-1, norbixina: 1,43 g.100g-1) e com a menor concentração não ocorreu conversão (KOH 0,6 por cento - bixina: 2,00 g.100g-1, norbixina: não detectada). A elevação da temperatura de extração esteve associada à redução do teor de bixina no meio e ao aumento do teor de norbixina (T70°C - bixina: 0,01 g.100g-1, norbixina: 2,34 g.100g-1; T25ªC - bixina: 1,04 g.100g-1, norbixina: 0,78 g.100g-1). Sendo assim, para extração de bixina seria recomendado o uso de soluções alcalinas pouco concentradas, ao passo que para a obtenção do pigmento hidrossolúvel são aconselhadas concentrações mais elevadas, podendo estar associadas a aquecimento.

This research aimed to evaluate the effect of different KOH concentrations (0.6 percent, 1 percent, 2 percent, 3 percent, 4 percent and 5 percent) and extraction temperature (25ºC, 50°C, 60°C and 70°C) on the progress of saponification reaction in annatto pigments. The progress of the reaction was monitored by quantification of bixin and norbixin using high performance liquid chromatography (HPLC). The highest alkali concentration made possible the maximum conversion of bixin into norbixin (KOH 5 percent - bixin: 0.44 g.100g-1, norbixin: 1.43 g.100g-1) and using the lowest concentration, saponification didn't take place (KOH 0.6 percent - bixin: 2.00 g.100g-1, norbixin: not detected). The elevation of extraction temperature was associated to a decrease of bixin content and to an increase of norbixin content (T70°C - bixin: 0.01 g.100g-1, norbixin: 2.34 g.100g-1; T25ºC - bixin: 1.04 g.100g-1, norbixin: 0.78 g.100g-1). Therefore, for the extraction of bixin is recommended to use alkaline solutions in low concentrations. To obtain the hydrossoluble pigment, higher concentrations are suggested, and they could be associated to heating.

Effect of temperature on concentration of active components extracted from medicinal herb / 中草药

Object To develop a mathematical model on the relationship between the temperature used in the course of extraction of medicinal herbs and the concentration of active component obtained Methods Based on the kinetic model on medicinal herb extraction process reported in our previous article *, diffusion coefficient and concentration gradient varying with temperature were further studied Results The process which tanshinone was extracted from Salvia miltiorrhiza Bge at different temperatures showed that the model could well match the experimental data Conclusion The relation between the temperature and the concentration of active component could be described by this model