Effects of nutriental and environmental conditions on carotenoid biosynthesis by Rhodotorula sp.

Carotenoid compounds are popular natural antioxidants which are commonly isolated from the plants. Recently, there have been many researches on carotenoid biosynthesis towards low cost products. In this study, Rhodotorula sp. was grown on an agricultural byproduct (corncobs) as a matrix in solid-state fermentation. Essential nutrients were added with different concentrations to optimize condition for the carotenoid biosynthesis. Effects of other environmental factors such as moisture content and fermentation time on the yield were also characterized. The optimal nutrient composition for the yeast’s growth and carotenoid biosynthesis is a compound of 500μg nitrogen and 16mg carbon in 100g matrix. Additionally, the moisture content of 80% is the best for producing carotenoid by this yeast strain. The fermentation time for the highest carotenoid yield is observed after 8 days

OPTIMIZATION OF ENZYMATIC HYDROLYSIS CONDITIONS FOR INCREASING THE EFFICIENCY OF EXTRACTED DRY MATTER FROM Limonia Acidissima PULP BY COMBINED CELLULASE -PECTINASE ENZYMES USING RESPONSE SURFACE METHODOLOGY (RSM)

The Limonia acidissima (L. acidissima) fruit is rich nutrient and bioactive compounds. Our research on the hydrolysis of L. acidissima pulp by combined cellulase and pectinase enzymes to increase the yield of dry matter and bioactive compounds for health benefit is important. In this study, the hydrolysis conditions by combined enzymes for the dry matter recovery were optimized by response surface methodology (RSM). The independent variables were coded pH (X1), incubation temperature (X2), the total content of combined cellulase-pectinase (X3) (with the ratio of cellulase/pectinase was 1/1), and hydrolysis time (X4). The results of the analysis of variance (ANOVA) showed that the variables actively affected the efficiency of extracted dry matter. The optimal conditions of hydrolysis were derived at x1 = 4.2, x2 = 45 oC, x3 = 1.6 % (v/dwt), x4 = 120minutes, respectively in the efficiency of the prediction model was 54.76 %. that increased 20.89 % in compared with non-enzymatic extraction. Besides, the recovery efficiency of carbohydrates was 87.74 %. Further, all the content of extracted phenolic content (TPC), carotenoic and DPPH and ABTS radical scavenging activity highly increased. That reached 106.7mg GAE, 86.6mg, 67.1 and 102.1 mg trolox equivalent antioxidant capacity (TEAC) from 100g L. acidissima pulp respectively

Physiochemical properties, antibacterial and antioxidant activities of Terminalia catappa seed oils from two extracting processes

Terminalia catappa is a widespread medium tree species in many tropical countries. While the majority of the studies up to date focuses on the aerial part of the plant such as leaf, stem bark and fruit, information about the phytochemical property as well as the biological property of the edible seed is still scarce. This study was the first to explore the fatty acid composition, antibacterial and antioxidant activities of the seed oil from T. catappa grown in Vietnam. The results showed that both the hot-pressed and cold-pressed oils contained a high level of unsaturated fatty acids such as oleic (~32%) and linoleic acids (28.38%-29.2%), as well as saturated fatty acids such as palmitic acid (~33.3%-33.61%). The presence of eicosadienoic acid in T. catappa seed oils was reported in this study for the first time. These oils displayed antibacterial activity against 5 out of 12 tested strains such as Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Vibrio parahaemolyticus. The antioxidant activity of the oils was also recorded by DPPH radical scavenging assays with IC50 values of 950 µg/ml and 2529 µg/ml for cold-pressed oil and hot-pressed oil respectively. This study has provided promising extracting methods and resulted in oils that could be good candidates for developing food sources with valuable fatty acids, antioxidant and antibacterial capacities against both Gram-positive and negative bacteria in the human diet

ENCAPSULATION OF LACTOBACILLUS ACIDOPHILUS IN YEAST CELL WALLS (SACCHAROMYCES CEREVISIAE) FOR IMPROVING SURVIVAL IN GASTROINTESTINAL CONDITIONS

In search of high-quality health products, it is required that probiotic preparations consumed in gastro-intestinal condition remain metabolically active and preserve their activity. Several recent studies, consequently, have focused on probiotic protection via encapsulation in order to optimize probiotics’ viability as well as their delivery into gastro-intestinal environment. The objectives of this study were to find out a new material for encapsulation of probiotics, utilizing capsules prepared from Saccharomyces cerevisiae to protect living probiotic cells. The encapsulation of cells was achieved, using the crack scars of the yeast cell walls (YCW) created by the sonication method. Besides, some probiotic cells can be considered as being encapsulated by some surrounded yeast cells by direct cell-cell contact. It is concluded that thanks to encapsulation by yeast cells, probiotic’s metabolic activity and survival are markedly improved. This suggests a high potential in protecting probiotics from the extreme condition of digestion process and can be applied in protecting probiotic preparations in food formulations as well. It was found that encapsulation yield in this study reached its highest point at 82.008 ± 1.123%. Viability of encapsulated probiotic in simulated gastric juice (SGJ) after 150 minutes is 19.048 ± 2.701%, compared to that of free cells at 0%. Likewise, after a 4-hour treatment in simulated intestinal juice (SIJ) (0.5% bile salt) encapsulated probiotic proves better survival at 56.338 ± 5.094% than free cell at 43.677 ± 2.058%

Awareness and preparedness of healthcare workers against the first wave of the COVID-19 pandemic: A cross-sectional survey across 57 countries.

BACKGROUND: Since the COVID-19 pandemic began, there have been concerns related to the preparedness of healthcare workers (HCWs). This study aimed to describe the level of awareness and preparedness of hospital HCWs at the time of the first wave. METHODS: This multinational, multicenter, cross-sectional survey was conducted among hospital HCWs from February to May 2020. We used a hierarchical logistic regression multivariate analysis to adjust the influence of variables based on awareness and preparedness. We then used association rule mining to identify relationships between HCW confidence in handling suspected COVID-19 patients and prior COVID-19 case-management training. RESULTS: We surveyed 24,653 HCWs from 371 hospitals across 57 countries and received 17,302 responses from 70.2% HCWs overall. The median COVID-19 preparedness score was 11.0 (interquartile range [IQR] = 6.0-14.0) and the median awareness score was 29.6 (IQR = 26.6-32.6). HCWs at COVID-19 designated facilities with previous outbreak experience, or HCWs who were trained for dealing with the SARS-CoV-2 outbreak, had significantly higher levels of preparedness and awareness (p<0.001). Association rule mining suggests that nurses and doctors who had a 'great-extent-of-confidence' in handling suspected COVID-19 patients had participated in COVID-19 training courses. Male participants (mean difference = 0.34; 95% CI = 0.22, 0.46; p<0.001) and nurses (mean difference = 0.67; 95% CI = 0.53, 0.81; p<0.001) had higher preparedness scores compared to women participants and doctors. INTERPRETATION: There was an unsurprising high level of awareness and preparedness among HCWs who participated in COVID-19 training courses. However, disparity existed along the lines of gender and type of HCW. It is unknown whether the difference in COVID-19 preparedness that we detected early in the pandemic may have translated into disproportionate SARS-CoV-2 burden of disease by gender or HCW type

Ventilator-associated respiratory infection in a resource-restricted setting: impact and etiology.

BACKGROUND: Ventilator-associated respiratory infection (VARI) is a significant problem in resource-restricted intensive care units (ICUs), but differences in casemix and etiology means VARI in resource-restricted ICUs may be different from that found in resource-rich units. Data from these settings are vital to plan preventative interventions and assess their cost-effectiveness, but few are available. METHODS: We conducted a prospective observational study in four Vietnamese ICUs to assess the incidence and impact of VARI. Patients ≥ 16 years old and expected to be mechanically ventilated > 48 h were enrolled in the study and followed daily for 28 days following ICU admission. RESULTS: Four hundred fifty eligible patients were enrolled over 24 months, and after exclusions, 374 patients' data were analyzed. A total of 92/374 cases of VARI (21.7/1000 ventilator days) were diagnosed; 37 (9.9%) of these met ventilator-associated pneumonia (VAP) criteria (8.7/1000 ventilator days). Patients with any VARI, VAP, or VARI without VAP experienced increased hospital and ICU stay, ICU cost, and antibiotic use (p < 0.01 for all). This was also true for all VARI (p < 0.01 for all) with/without tetanus. There was no increased risk of in-hospital death in patients with VARI compared to those without (VAP HR 1.58, 95% CI 0.75-3.33, p = 0.23; VARI without VAP HR 0.40, 95% CI 0.14-1.17, p = 0.09). In patients with positive endotracheal aspirate cultures, most VARI was caused by Gram-negative organisms; the most frequent were Acinetobacter baumannii (32/73, 43.8%) Klebsiella pneumoniae (26/73, 35.6%), and Pseudomonas aeruginosa (24/73, 32.9%). 40/68 (58.8%) patients with positive cultures for these had carbapenem-resistant isolates. Patients with carbapenem-resistant VARI had significantly greater ICU costs than patients with carbapenem-susceptible isolates (6053 USD (IQR 3806-7824) vs 3131 USD (IQR 2108-7551), p = 0.04) and after correction for adequacy of initial antibiotics and APACHE II score, showed a trend towards increased risk of in-hospital death (HR 2.82, 95% CI 0.75-6.75, p = 0.15). CONCLUSIONS: VARI in a resource-restricted setting has limited impact on mortality, but shows significant association with increased patient costs, length of stay, and antibiotic use, particularly when caused by carbapenem-resistant bacteria. Evidence-based interventions to reduce VARI in these settings are urgently needed

Anthocyanin isolation from Hibiscus sabdariffa L. flowers by extraction, macroporous D101 resin purification, and biological evaluation

This study aimed to improve the purity of anthocyanins in the extract from Hibiscus sabdariffa L. (H. sabdariffa L.) by macroporous D101 resin. Thereby, we determined the main components, thermal stability properties, and some biological activities of anthocyanin mixture from Hibiscus flowers. The main anthocyanin identified in the anthocyanin sample was Cyanidin-3-O-sambubioside. In the purification stage with D101 resin, the anthocyanin fraction had the highest purity of 72.18 % compared with 12.07 % of that of the extract. Purified anthocyanins have very good color stability at low temperatures and in mildly alkaline media. The high antioxidant capacity of anthocyanins was recorded by methods of the free radical scavenging capacity of 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and Ferric-reducing antioxidant power (FRAP) with IC50 values of 93.14 ± 0.93 μg/mL, 75.51 ± 0.71 μg/mL and 73.26 ± 0.93 μg/mL, respectively. The total antioxidant activity (RP) of anthocyanin sample was dose-dependent, the absorbance increased from 0.149 (100 μg/mL) to 0.873 (500 μg/mL). Anthocyanin also can inhibit both Gram (+) and Gram (−) bacteria of Staphylococcus aureus and Escherichia coli, as well as the mold Aspergillus flavus. Research has also shown potential anti-inflammatory in vitro of anthocyanins. These findings provide evidence that the purified anthocyanin from H. sabdariffa L. is a potential source of natural antioxidants, anti-bacteria, and anti-inflammatory in functional food and medicine

Effect of blanching, freezing and microwave-assisted pretreatment methods on chlorophyll extraction from Sauropus androgynus leaves

Sauropus androgynus is grown commonly in Vietnam, which has a high content of bioactive substances including chlorophyll, polyphenols, and antioxidant activity. Sauropus androgynus is used as food or a colorant for traditional Vietnamese cakes. Green pigments are employed in various industrial sectors, such as food, drinks, soap, and drug. Chlorophyll can be replaced synthetic green pigments that might be unhealthy. In this study, the effect of chlorophyll extraction efficiency and perceptional green color by extraction condition combinined with physical pretreatment methods was investigated using Sauropus androgynus leave as a model. Fresh raw materials were pre-treated by blanching, freezing and microwave treatment at 55w/g for 3 min and then extracted with 40% (v/v) ethanol solvent. The best chlorophyll recovery efficiency (CRE) from Sauropus androgynus by heat pretreatment methods with and without microwave assistance was 32.035% and 25.784% of chlorophyll content in material; or 1.081 mg/g d. w and 0.862 mg/g d. w of fresh leaves, respectively. The chlorophyll extract is then spray-dried to form a water-dispersible powder. Chlorophyll extracted with microwave-assisted pretreatment having high CRE that has potential applications in food production, but green color is not much more favorable than the non-microwave assisted sample

Formulation of black pepper (Piper nigrum L.) essential oil nano-emulsion via phase inversion temperature method

Recent trends in preservation of processed foods involve the use of natural compounds, rather than chemically synthesized additives, to simultaneously confer antimicrobial properties and prevent fat oxidation. In this regard, black pepper essential oils, due to its diversity in biological activities, have been increasingly popular. The compounds are often used in relatively low amounts and in the form of nanoparticles to permit well blending into foods or uniform dispersion on the surface of fresh meat. The purpose of this study is to determine experimental parameters of a nano-emulsion formation process from black pepper essential oil via the phase inversion temperature (PIT) technique. The study results showed that the system achieved the optimal nano-emulsion under following condition: the ratio by weight of water: Tween-80: oil = 86:9.7:4.3, the stirring speed of nano-emulsions at 500 rpm for 45 min (heating at 75°C for 30 min and then rapidly cooling at 5°C for 15 min)