Temperature 30oC Research Articles

Enhanced Phenanthrene Biodegradation by Bacillus brevis Using Response Surface Methodology

The current investigation assessed the capability of a well-adapted and enriched bacterial strain known as Bacillus brevis for the biodegradation of phenanthrene. To enhance the removal efficiency of phenanthrene, employed Response Surface Methodology (RSM) in conjunction with a Box-Behnken design (BBD) model. The experiments were designed to explore the impact of pH (6.0 to 9.0), temperature (20 to 40°C), initial phenanthrene concentration (50 and 100 ppm), and incubation time (7 to 21 days) on biodegradation of phenanthrene. The highest level of phenanthrene biodegradation, approximately 55.0%, was achieved by Bacillus brevis when the optimal conditions were met as pH of 7.0, temperature 30oC, and initial phenanthrene concentration (70 ppm) after 21 days of incubation time. This study underscores the significance of employing statistical tools like RSM to enhance the microbial degradation of contaminants.

Potential and Activities of the Sunscreen Lotion Preparation of Bawang Dayak (Eleutherine americana (Aubl.) Merr. by Ethanol Extract Fraction from East Boneo

Has conducted research Potential and Activities of the Sunscreen Lotion of Bawang Dayak (Eleutherine americana (Aubl.) Merr. by ethanol extract fraction from East Borneo. The purpose of the study was to determine the potency ann activity of the sunscreen ethanol extracts fraction of Bawang Dayak in the preparation of a lotion with the parameter measuring the percent transmission erythema (% Te) and pigmentation (% Tp) in vitro in the room temperature 27oC storage and accelerated temperature 40oC. Lotion dosage formulations using ethanol extracts fraction bawang Dayak with a concentration of 0.1% and 0.2%, and positive control is a trademark preparation Bless Sunscreen Lotion SPF 15®. Stages of research include the formulation and measurement of absorbance and value %Te) and %Tp at various storage temperatures with UV-Vis spectrophotometry at λ 292.5 to 372.5 nm. The analysis of research data using a program SPSS. The results showed that ethanol extract fraction concentration in lotion preparations of bawang Dayak 0.1% and 0.2% active as a sunscreen included in the category of sunblock. The extract fraction is active as a sunscreen and in the Sunbloc category, with the best concentration as a sunscreen being 0.2%, with its sunscreen potential not being significantly different from the control Sunscreen SPF 15® at the 5% level.

Optimization and purification of L-methioninase enzyme purified from clinical samples of Pseudomonas spp.

Background: This study focused on Pseudomonas aeruginosa, which secrete important enzymes in medical and pharmaceutical applications and are isolated from clinical samples. One of these enzymes is L-methioninase, the most desirable enzyme in the medical and industrial fields today since it converted L-methionine into methanethiol, ammonia, and alpha-ketobutyrate. Objectives: Evaluated the optimum conditions of L-methioninase production and then purified it. Methods: Pseudomonas samples were identified by microscopic and biochemical tests and confirmed with the VITEK2 system. After the L-methioninase production was examined, the optimal conditions for the production of L-methioninase (MGL) were established using clinical samples of P. aeruginosa. Additionally, MGL was purified from the supernatant of P.aeruginosa using ammonium sulfate precipitation, DEAE-cellulose, and Sephadex G150 accordingly. Results: There were 33 isolates of P.aeruginosa according to microscopic characteristics and biochemical tests, followed by the VITEK2 system to ensure identification. The optimization conditions were achieved when supplement media with sucrose 1% w\v, casein 1% w\v, pH 7, temperature 37oC, and incubation for 48hrs within the specific activity of 1.6, 3.3, 3.4, 3.4, and 3.5U\mg protein, respectively, and 4.6 fold the amount of the purified enzyme as compared to the crude enzyme. A single 55 kDa band on the SDS-PAGE indicates the enzyme is purified. Conclusions: P.aeruginosa can be an efficient source of L-methioninase, and this enzyme had better and higher specific activity after applying optimum conditions for it and purifying it.

Robust Design Liquid Black Garlic Supplement Production System By Considering Hazard Analysis And Critical Control Points

Black Garlic granules serve to help prevent and treat diabetes and cardiovascular disease. In this study, a BG-based liquid supplement production system was designed which is expected to become a BG-based liquid supplement production standard that pays attention to product safety, product quality and production efficiency. This research will design BG's production process to meet quality specifications and food safety standards along with the production system. The research will be conducted by conducting Taguchi experiments and then continued with Hazard Analysis and Critical Control Points (HACCP). At the experimental stage, several important BG quality attributes were selected in response. The factors that affect quality are determined through Focus Group Discussions involving company stakeholders. Experiments were conducted using laboratory scales. The results of Taguchi's experiments that have been carried out, it is concluded that using the optimal level settings chosen can reduce SAC levels, namely A1 = Cleaning and Weighing Equipment (Using a Washing Bucket), B1 = BG Formulation Temperature (30oC), C1 = BG Formulation Time (60 minutes), D2 = Cooling Process (Accelerated), E1 = Storage Packaging (Aluminum Sachet), F1 = Storage Temperature (28oC), G1 = BG Treatment (Peel).

COMPARISON OF TRIETHANOLAMINE (TEA) AND ETHYL VINYL ACETATE (EVA) AS FLOW IMPROVERS OF CRUDE OIL.

This research presents a study on the comparative analysis of the efficiencies of triethanolamine (TEA) and ethylvinylacetate (EVA) as flow improvers for crude oil transport. Varied concentrations (by volume percentage) of 0%, 0.025%, 0.05%, 0.1%, 0.2%, 0.4% and 1% of triethanolamine were introduced into separate but same quantities of crude oil and stirred. The viscosity and pour points were monitored at varied temperatures (30oC, 40oC, 50oC, 60oC, 70oC) to ascertain optimum concentration and temperature of best flow improvement with that of zero concentration serving as control. Similar thing was done with EVA at same conditions. TEA and EVA both drastically dropped viscosity of the crude close to what temperature alone could offer but rose immediately after the minimum concentration of 0.025% with EVA and TEA on further diluent addition. TEA viscosity rose steeply and later tended towards a constant viscosity. This was also the trend with EVA, but it rose gently unlike TEA at increased concentration of the additive. Using room temperature (30oC) for the two additives (TEA and EVA) as reference point at 0.025% concentration of each to the same volume of crude oil, TEA gave a minimum viscosity of 0.1124centistokes and EVA gave 0.1184centistokes. Similar trend was also observed at the apex temperature (70oC) at 0.025% concentration (TEA viscosity = 0.0997centistokes and EVA = 0.1015centistokes). In the end, TEA was observed to be better than EVA although EVA has its own relative advantage especially at higher temperatures and concentrations. Higher temperature from 40oC and above degraded TEA but not EVA, as a result was inhibitory to the reverse rise in viscosity in TEA. Hence, having established TEA and EVA as good drag reducing agents, the additives if used in the proper calculated quantities will act optimally in improving crude oil transport. Outcome of this research will find application in our oil and gas industry where challenges in crude oil transport has been overwhelming as a result of wax formations in the pipelines.

Kinetics studies on the ascorbic acid extraction from roselle (Hibiscus sabdariffa) calyces

The effect of processing conditions of roselle (Hibiscus sabdariffa) calyces on the vitamin C content of the extracts was studied to develop models that best describe the process. The extraction parameters are the processing time (5, 10, 15 mins), process temperature (30oC, 50℃, 75℃ and 100℃), and calyx-water mass ratio (1:50, 1:20 and 1:10). These samples were tested for ascorbic acid using the spectrophotometric method. Statistical analysis was conducted on the experimental results and regression models were developed. A total of six mathematical models were selected for the description of vitamin C extraction from the calyces. The results showed that time, temperature and calyx-water mass ratio have a linear significant effect (p ≤ 0.01); while time-temperature and temperature-ratio had a significant (p ≤ 0.05) interaction effect; time and temperature had a significant (p ≤ 0.05) quadratic effect on the vitamin C content of the extract. Pseudo-first-order gave the highest overall coefficient of determination R2 and lowest overall root mean square error (RMSE). The activation energy of vitamin C ranged from 3 to 8.4 kJ; the effective diffusion coefficient ranged from 1.5×10-9 to 5.0×10-7 m 2 s -1 ; while mass diffusivity ranged from 3.11×10-5 to 8.6×10-4 ms-1 . The Biot number calculated ranged between 33.93 and 541.94 which showed that there is an insignificant external mass transfer resistance.

Effect of Blanching Temperature and Convective Hot Air-drying Temperature of Orange Peel Slices on Its Quality Evaluation

Drying characteristics of orange peel was investigated by blanching and convective hot air drying of orange peel slices (of 3mm thickness) at the temperature 40ºC, 50ºC and 60ºC. Drying models i.e. Lewis, Henderson and Pabis and Page were fitted to the experimental data on moisture ratio with respect to time. The page model fitted well r^2≥0.976 and MSE≤0.0012 among all the models tested for the experimental data. Effective diffusivity (Deff) at time (t) for orange peel were 0.086×10-8m2/s, 1.834×10-8m2/s and 2.017×10-8m2/s which was blanched at 72ºC:10 min, 82ºC:8min and 92ºC:5 min and dried at 40ºC; 0.0903688×10-8m2/s, 1.077×10-8m2/s and 1.898×10-8m2/s which was blanched at 72ºC:10 min, 82ºC:8min and 92ºC:5 min and dried at 50ºC; 1.168×10-8m2/s, 1.422×10-8m2/s and 1.579×10-8m2/s which was blanched at 72ºC:10 min, 82ºC:8min and 92ºC:5 min and dried at 60ºC. The activation energy (Ea) for moisture diffusion was found to be 2.244×104 kJ/mole, 2.523×104 kJ/mole and 1.262×104 kJ/mole. The quality parameter i.e. T.S.S was in 20 to 60(°B), acidity was in the range of 0.32 to 18.09 %, reducing sugar was in the range of 19.05 to 6.21 % non-reducing sugar was in the range of 2.56 to 10.13%, total sugar was in the range of 9.08 to 25.8%, pH was in the range of 5.4 to 3.6%, ascorbic acid was in the range of 18.2 to 34.76%, yellowness index was in the range of 77.76 to 154.40 and protein was in the range of 8.60 to 11.24% on orange peel powder prepared from blanching at 72ºC: 10 min, 82ºC: 8min and 92ºC: 5 min dried at 40⁰C, 50⁰C and 60⁰C respectively were determined and discussed.

Determination of fermentation conditions of Streptomyces sp. VNUA116 to improve the antifungal activities against Fusarium oxysporum f.sp. cubense causing Panama wilt disease on banana plants

This study aims to identify medium components (carbon source, carbon concentration, nitrogen source) and fermentation conditions (temperature, pH) to enhance the resistance against Fusarium oxysporum f. sp. cubenseTropical Race 4 (Foc Tr4), causing Panama wilt disease of Streptomyces sp. VNUA116 (VNUA116). By using the agar well diffusion method, it was determined that strain VNUA116 has strong anti-fungal pathogen activities FocTr4 under fermentation nutrients: YIM 301 medium, carbon source CB1 (soluble starch 40 g/l: D-glucose 1 g/l, and nitrogen source N1 beef extract 3 g/l: yeast extract 5 g/l: peptone 3 g/l). Additionally, optimal fermentation conditions were established, including pH 7, and temperature 30oC. Strain VNUA116 exhibited the highest antifungal activity, reaching a diameter of 30.67±0.58 mm after 10 days of cultivation. Furthermore, under these optimised fermentation conditions, Streptomycessp. VNUA116 demonstrated an impressive inhibitory capability against Foc-Tr4, reaching up to 93.20%, equivalent to the concentration of the fungicide Ridomil gold 68WG at 3 g/l in laboratory conditions. This affirms the considerable potential of the VNUA116 strain for applications in the production of biofertilizers for the biological control of Panama wilt disease in banana plants.

PAHs Biodegradation by Locally Isolated Phanerochaete chrysosporium and Penicillium citrinum from Liquid and Spiked Soil

In the present study, biodegradation of polycyclic aromatic hydrocarbons (PAHs) was examined using two fungal strains, namely P. chrysosporium and P. citrinum, isolated from locally contaminated soil. These two fungal strains were compared based on degradation properties under standardized conditions (pH 7.0, temperature 30oC, carbon source yeast extract) using PAH sole and a mixture of five different PAHs. In liquid media, PAH degradation was higher as compared to spiked soil by P. chrysosporium, followed by P. citrinum. In liquid culture, maximum degradation was 96.13% phenanathrene, 86.34% fluoranthene, 72.75% pyrene, 52.25% chrysene, and 40.16% benzo(a)pyrene by P. chrysosporium. PAH degradation in spiked soil was 78.5% phenanthrene, 65.91% fluoranthene, 61.73% pyrene, 48.2% chrysene, and 26.82% benzo(a)pyrene within 28 days by P. chrysosporium. Both local fungal isolates showed potential for degradation of PAHs alone and in PAH mixtures.

Extraction of Natural Food Color from Tomato, Carrot and Turmeric

The demand for natural and healthier food products has increased dramatically in recent years due to growing consumer awareness of the impact food has on health as well as evidence of adverse effects from various ingredients, including some additives. This study evaluates the extraction method, solvent effects, precipitation, identification, purification, and lycopene, carotene, and curcumin content from turmeric, carrot, and tomato. Along-side, tomato, carrot, and turmeric samples were subjected to two different extraction and purification processes: solvent extraction for lycopene and carotene, and alkalization for curcumin. The samples were extracted and purified at room temperature (30ºC) and chilled (4ºC) for a period of three weeks. Tomato extracts had lycopene contents ranging from 0.0153 to 0.0362 mg/100g. obtained carotene content, which was then extracted using a solvent in the range of 61.43 to 81.72 mg/100g. The alkalization process produced a curcumin concentration of 91.17 to 110.41 mg/100g. Comparing the ethyl acetate extraction technique to the anti-solvent method, a greater amount of lycopene (red) and carotene (orange) precipitation was obtained. The maximum amount of curcumin precipitation obtained in lower pH solution. Lower pH is important to maintain the stability of curcumin precipitation. The experience of this research work suggested that lycopene from tomatoes, carotene from carrots, and curcumin from turmeric might be an excellent source to meet the increasing need for natural colorants.

Simultaneous Estimation of Naltrexone Hydrochloride and Zonisamide in Synthetic Mixture by RP-HPLC Method

A simple, rapid, precise, and reproducible RP-HPLC method development and validation done for simultaneous estimation of Naltrexone Hydrochloride and Zonisamide in synthetic mixture. The isocratic method was developed usinɡ a Water Symmetry C18 (250 mm X 4.6 mm, 5 µm) column. Mobile phase composition was Phosphate Buffer: Methanol (75:25 %V/V) (Buffer-1.36 ɡ of KH2PO4 in 1000 ml adjust pH 3.0 ± 0.05 with OPA.), flow rate 1 ml/min and detection carried out at 230 nm at column temperature 30ºC. The injection volume was 10µl with run time of 10 minutes. Parameters such as linearity, precision, accuracy, recovery, specificity and robustness are performed as per ICH ɡuidelines Q2(R1). Retention time of Naltrexone Hydrochloride and Zonisamide were found to be 3.92 min and 8.15 min respectively. The developed method found linear in the ranɡe of 1-10 µɡ/ml for Naltrexone Hydrochloride and 2.84-142 µɡ/ml for Zonisamide (R2 = 0.9999 for both druɡs). The % Recovery were found to be 99.39 %-100.70 % and 98.91 %-100.59 % for Naltrexone Hydrochloride and Zonisamide respectively. The RSD for both druɡ were less than 2 for precision, specificity and robustness.

НОВЫЙ ПОДХОД К ПОЛУЧЕНИЮ КОМПЛЕКСООБРАЗУЮЩИХ СОРБЕНТОВ, СОДЕРЖАЩИХ ИМИНОДИАЦЕТАТНУЮ ГРУППУ

The results of the study of chemical modification of synthetic boehmite (γ-AlO(OH)) surface with phosphonic complexone - imino-N,N-diuacetic-N-methylene phosphonic acid (PMIDA) to obtain a new complexing material capable of binding heavy metal ions are presented. The technique of simple one-step modification of boehmite by its treatment with aqueous solution of PMIDA (pH 2, temperature 20oC, time 6 h) was developed. The IR spectrum of the obtained PMIDA- boehmite shows bands characteristic of phosphonic -PO(OH)2 (900-1300 cm-1) and carboxyl -COOH (1637 cm-1 and 1386 cm-1) groups. As a result of modification, a dense coating (0.61 mmol/g or 1.5 groups/nm2) is formed on the surface of boehmite, in which the phosphonic group of PMIDA is the ‘anchor’ of the modifier, and the free iminodiacetate group shows complexing properties. The phosphonic coating was found to be hydrolytically stable at pH 2-7. It is shown that the sorption of metal ions (Ni(II), Cu(II)) by PMIDA- boehmite occurs in a more acidic environment compared to the original boehmite (shift of pH50by 2-3 units). Cu(II) ions bind to the -N(CH2COOH)2 group of fixed PMIDA more strongly than Ni(II) ions, similarly to the case for complexonates of these metals with PMIDA in solutions. PMIDA- boehmite can be recommended as a new effective material for sorption extraction and concentration of heavy metal ions under static conditions (sorption time 60 min). The developed method of fixation of iminodiacetate group using PMIDA can also be used in relation to other oxide carriers.

Influence of Diffusion Time and Temperature on Restricted Diffusion Signal: A Phantom Study.

Diffusion MRI is a physical measurement method that quantitatively indicates the displacement of water molecules diffusing in voxels. However, there are insufficient data to characterize the diffusion process physically in a uniform structure such as a phantom. This study investigated the transitional relationship between structure scale, temperature, and diffusion time for simple restricted diffusion using a capillary phantom. We performed diffusion-weighted pulsed-gradient stimulated-echo acquisition mode (STEAM) MRI with a 9.4 Tesla MRI system (Bruker BioSpin, Ettlingen, Germany) and a quadrature coil with an inner diameter of 86 mm (Bruker BioSpin). We measured the diffusion coefficients (radial diffusivity [RD]) of capillary plates (pore sizes 6, 12, 25, 50, and 100 μm) with uniformly restricted structures at various temperatures (10ºC, 20ºC, 30ºC, and 40ºC) and multiple diffusion times (12-800 ms). We evaluated the characteristics of scale, temperature, and diffusion time for restricted diffusion. The RD decayed and became constant depending on the structural scale. Diffusion coefficient fluctuations with temperature occurred mostly under conditions of a large structural scale and short diffusion time. We obtained data suggesting that temperature-dependent changes in the diffusion coefficients follow physical laws. No water molecules were observed outside the glass tubes in the capillary plates, and the capillary plates only reflected a restricted diffusion process within the structure.We experimentally evaluated the characteristics of simple restricted diffusion to reveal the transitional relationship of the diffusion coefficient with diffusion time, structure scale, and temperature through composite measurement.

Effect of Native Trichoderma as Seed Treatment on Germination and Seedling Performance of Lentil Under Biotic and Abiotic Stress Conditions

Physiological and water stress conditions substantially impede seed germination and the establishment of plant population. In 2020, a study was conducted in a completely randomized design (CRD) to identify potential Trichoderma strains that could alleviate physiological and water stress in germinating seeds. To create physiological stress, seeds were kept in an incubator at high relative humidity (90%) and temperature (40ºC) for 20 days. Similarly, to induce water stress on germinating seeds, Polyethylene glycol (PEG) was applied in four concentrations (0, 5, 10, and 15%). Nine different isolates of Trichoderma were isolated from forest and agricultural soil and conidial suspension was applied to lentil seeds to deposit 107cfu per gram of seeds. For each treatment, a total of one hundred seeds were placed on three layered moist blotter paper and incubated at 25±2°C. Germination was measured after every 24 hours. Under stress conditions, seeds treated with Trichoderma exhibited enhanced germination, root and shoot length, dry and fresh weight of root and shoot of seedlings as compared to untreated seeds. Highest seed germination under physiological stress and water stress was observed with Trichoderma isolates T87, Forest soil and T62, Darchula respectively. Isolate T87, Forest soil demonstrated the highest vigor index of seedlings in stress conditions. Seed treated with Trichoderma isolates also displayed significant improvement in germination under biotic stress induced by Sclerotium rolfsii. Trichoderma isolate T31, Banke showed highest germination under biotic stress. These findings highlight the potential of Trichoderma to enhance plant resilience and promote healthier growth under challenging environmental conditions. SAARC J. Agric., 21(2): 145-156 (2023)

PERBEDAAN AKTIVITAS ANTIOKSIDAN PADA KOLANG KALING SEGAR DAN KOLANG KALING SERBUK

Kolang kaling (Arenga pinnata) is one of the results of the palm tree. The process of processing palm fruit into and fro can affect the quality of the fruit and fro produced. The purpose of this study was to determine the physico-chemical characteristic, IC 50 value of fresh fruit and fro, the powder was dried in the microwave at low temperature (40oC) for 5 days, medium (53oC) for 4 hours and high (78oC) for 2 hours, and to find out whether there are effect of difference in fresh fruit and fro treatment on antioxidant activity.  Fresh fruit and fro were tested for phytochemical screening and FTIR, physicochemical characteristics and antioxidant, Antioxidant testing used the DPPH (1,1-diphenyl-2-picrylhidrazyl) method. The results of phytochemical screening and FTIR showed the presence of galactomanan compounds.  The antioxidant test results obtained the IC50 value of fresh fruit and fro, the powder was dried in the microwave at low temperature, medium and high respectively 104.8488; 25.2963; 90.0155 and163.4381 ppm. The statistical test results showed a value of 0.000<0.05, there is a difference IC50 between groups

ỨNG DỤNG CÔNG THỨC KHÁNG NẤM TỪ THIÊN NHIÊN CHO SẢN PHẨM TRE, GỖ GIA DỤNG

This paper is concerned with the ability of natural products such as vinegar, tea, okra, lemon juice, grapefruit peel essential oil, and baking soda to prevent mold growth on bamboo and wood materials. The results showed that grapefruit peel essential oil had the highest biological activity compared to the other products in preventing mold growth on wood materials. Additionally, a process for preventing mold growth on bamboo and wood materials was developed and the parameters were optimized using the Box-Behnken surface response correlation method. The optimal process conditions were determined by analyzing the response surface of the three-dimensional surface plot and solving the regression model equation using Design Expert software. The optimal conditions, including the ratio of product to coverage area 5/1, concentration 53%, time in 238 minutes and temperature 40𝑜𝐶, have been tested and showed that the time for mold appearance was 254 days.

Optimization of ultrasound-assisted enzymatic extraction of betalains from red beetroot (Beta vulgaris L.)

Betalains in red beetroot (Beta vulgaris L.) offer health benefits and are commonly used as a food colorant. This study aimed to investigate betalains extraction using ultrasound-assisted enzymatic extraction (UAEE). The most significant factors involved in UAEE such as enzyme concentration, extraction temperature, and extraction time were studied and optimized using the response surface method (RSM) to achieve the highest betalains yield. The results showed that the optimal extraction conditions were as follows: enzyme concentration (32.1 U/mL), extraction temperature (40oC), and extraction time (117 min) gave the highest yield of betalains at the level of 550.51 ± 25.76 mg/L. The findings are promising for the industrial scale of extraction betalains for food applications.

Numerical Analysis of Using R449A Refrigerant Alternative to R404A in Cooling Systems: 3E-Analysis (Energetic, Exergetic, and Environmental)

The direct impact of refrigerants on the environment is largely dependent on the magnitude of global warming potential (GWP) values. In this regard, fluids with low GWP are very important for the environment. Commercial refrigeration accounts for about a third of the world's HFC use. R404A is a derived HFC near an azeotropic mixture. The refrigerant of R404A is widely used in commercial refrigeration systems, especially in supermarkets. As a result of the use of R404A in cooling systems with high GWP, both indirect and direct negative effects on the environment increase. In this study, the energy, exergy, and Life Cycle Climate Performance (LCCP) of R449A, which has a lower GWP value, which can be an alternative to R404A refrigerant, were investigated theoretically. Different evaporator temperatures (-30oC to -5oC) and a condenser temperature (30oC) were used in the analysis. According to the results obtained, while the mass flow rate of R449A is approximately 13% lower than that of R404A, its exergy efficiency is 5% higher. R449A was found to be approximately 5% lower than R404A in LCCP analysis.

Color Stability and Antioxidant Activity of Red Roselle (Hibiscus Sabdariffa L.) Calyx Infuse

The roselle flower (Hibiscus sabdariffa L.), is known as a potential functional food source because of its antioxidant and antibacterial properties. Apart from that, it is also used as a natural dye because of its red color. Antioxidant compounds in roselle flowers include neo-chlorogenic acid, chlorogenic acid, cryptochlorogenic acid, routine, and isoquercitrin. The high content of these antioxidant compounds often causes color instability. For this reason, this research will analyze the effect of temperature and long storage on color changes and the antioxidant activity of a red roselle flower infusion. Storage conditions are carried out with three temperature variations, namely cold temperature (2–8 oC), cool temperature (8–15 oC), and room temperature (15–30oC), with a long storage of 8 days. The stability parameters used are color changes and activity as an antioxidant. Color changes were measured using a chromameter, while the antioxidant activity was measured by the IC50 value using the DPPH method. The principle of this method is that a purple color change reaction based, which fades, and then the inhibitory intensity against DPPH is measured using UV-Vis spectrophotometer. It was found that the color values have significant differences visible from the first day storage at the room temperature (30oC), cool temperature (11oC), and cold temperature (6 oC). So, there was an influence of temperature and long storage on the color change of boiled red roselle flower calyx. A significant decrease in activity was seen on the first day storage at room temperature (30 oC) and third day storage at cool temperature (11 oC). Meanwhile, at cold temperatures (6 oC), there was no significant effect on the reduction in activity from boiling red roselle flower calyx for up to 8 days of storage

Effects of different drying methods on the micronutrients of four leafy vegetables traditionally consumed by some Clans in Izzi and Unwana, Ebonyi State, Nigeria

This study was carried out to evaluate the effects of different drying methods (Freeze drying, shade drying and oven drying at varied temperatures of 40oC, 50oC and 60oC) on the micronutrients (mineral and vitamin) contents of L. cupanioides, F. ottonifolia, P. osun and C. pentandra. The minerals contained in both dried and fresh leafy vegetable samples were analyzed by the dry ash extraction method, while vitamins (A, B1, B2, B6 and E) contents of the leafy vegetable samples were determined spectrophotometrically. Vitamin C was determined titrimetrically after homogenizing each sample in 50ml 5.6M EDTA solution. The results from the study revealed that the various drying methods affected the leafy vegetable samples within and between them in the same pattern but to different degrees resulting to moisture lose with increase in minerals and increase in vitamin concentrations when compared with the fresh leafy vegetable samples. Freeze drying and shade drying had the best micronutrients retention effects across all the leafy vegetable samples while oven drying at varied temperatures of 40oC, 50oC and 60oC had gradual decrease in minerals and vitamins retention effects as the temperature increases. The difference in mineral and vitamin concentrations retention with respect to drying methods decreased in this order: Freeze drying > shade drying > oven drying at 40oC > oven drying at 50oC > oven drying at 60oC. The results of the various micronutrients for both fresh and dried leafy vegetable samples in this study ranged as thus: Calcium (72.59–398.10mg/100g), magnesium (41.16–461.07mg/100g), phosphorus (79.28–306.11mg/100g), iron (2.11–32.11mg/100g), zinc (0.19–18.88mg/100g), sodium (29.10–326.51mg/100g), potassium (0.8-196.31mg/100g), vitamin B1 (0.31– 4.22mg/100g), vitamin B2 (0.31 –1.49mg/100g),vitaminB6 (0.36–3.91mg/100g), vitamin A (110.01–548.22ug/g), vitamin C (159.84–818.46mg/100g) and vitamin E (0.16– 9.91mg/100g). In conclusion, the freeze drying and shade drying are the best drying methods for producing dried traditional leafy vegetables with higher micronutrients retention than oven drying at varied temperatures (40oC, 50oC and 60oC).