The purpose of this study was to determine the effects of soaking temperature (25 and 80° C) and different processing conditions on the rheological properties of chia seeds (Salvia hispanica L.) mucilage. In this study, chia mucilage was first extracted using a ratio of seed to water at 1:10 for 4 hrs for control (25°C) and treated mucilage (80°C). Both extracted mucilage were evaluated in terms of yield, color, solubility, and water holding capacity. Then, the mucilage were subjected to different processing conditions including temperatures (5, 25, 45, and 65°C), pH (3, 5, 7, 9), sucrose concentrations (10, 20, 30, 40%), and salts (NaCl and KCl from 0 to 0.172 M; CaCl2 and MgCl2 from 0 to 0.049 M) to determine their rheological properties. Results show that high extraction temperature (80°C) significantly affected the mucilage yield higher than control. However, lightness (L*), solubility and water holding capacity of the treated sample were lower compared to control. Apparent viscosity of the 3% of mucilage for both extracts increases with temperatures and sucrose concentration. The high apparent viscosity of the treated mucilage at MgCl2 (0.049 M) and CaCl2 (0.049 M) concentration were found higher than 0.01 M. Meanwhile, NaCl (>0.069 M), KCl (>0.035 M), and CaCl2 (<0.03 M) had decreased the apparent viscosity value of the control sample. Thus, the treated mucilage could be suitable for application as a thickening agent in food.

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Arabic gum is derived from the exudation of stems and branches of Acacia senegal L. and it is widely used as a food additive. The application of Arabic gum as a functional food ingredient is significantly increasing. However, there is limited information on the effects of particle size on the handling and processing of Arabic gum in the industry. Therefore, a study was performed to determine the effects of particle size on the physical properties of Arabic gum powder. The physical properties measured were density, flowability, and dissolution characteristics. In this work, the powders were classified based on their mean diameter (d50) that ranged between 20 and 1,000 μm. The very fine powder exhibited poor flowing properties and long dissolution time, with a Hausner ratio of 1.24 ± 0.1 and dissolution time of 2,821.0 ± 76.0 s. However, the coarse powder had excellent flowing properties and shorter dissolution time, with a Hausner ratio of 1.13 ± 0.02 and dissolution time of 531.5 ± 70.5 s. The results indicated a significant impact of particle size on the cohesivity and solubility of powder, where smaller particle size tended to decrease flowability and increase the dissolution time of the powder. Practical applications This paper studies the characterization of Arabic gum at various particle sizes. The physical properties measured were density, flowability, and dissolution of Arabic gum powder. The results of this study indicate that particle size had significantly affected the powder properties. This knowledge is very important, as Arabic gum is widely used as a food ingredient; this might affect the overall product properties. The outcomes are also beneficial to the industry prior to selecting the specific particle size for the designing and processing of products. Therefore, the results on flowability and dissolution properties of Arabic gum powder can be used as guidance for the development of food product.

Mangosteen peel (MP), an agricultural by-product of tropical countries, has been reported to contain condensed tannins and saponins, which can affect rumen microbes to reduce enteric methane emission. In the present study, the effects of mangosteen peel on in vitro ruminal fermentation, gas production, methane production, fatty acid biohydrogenation, and microbial population were investigated. Results showed that MP at medium and high levels (25 % and 50 % replacing alfalfa) were able to reduce (P <0.05) in vitro methane production without affecting volatile fatty acid (VFA) production and the pH of the substrate. The lowering effect of MP on methane production was because of suppression of the rumen microbial populations, especially total protozoa and total methanogens. MP at the higher level (50%) reduced (P <0.05) the amounts of biohydrogenation for linoleic acid (C18:2n-6), α-linolenic acid (C18:3n-3) and the total C18 unsaturated fatty acids (UFA) owing to the reduction of the Butyrivibrio fibrisolvens population, that is, the most important rumen microorganism involved in the biohydrogenation process. In conclusion, mangosteen peel has potential to be used in ruminant livestock feeds, with the advantage of reducing ruminal methane production and biohydrogenation, without adverse effects on ruminal pH and VFA production. ______________________________________________________________________________________

This study consists of two parts. The first part is to identify the fatty acid composition of chia seed oils obtained by Soxhlet method using acetone and hexane as extraction solvents with different extraction times including acetone 4 hrs (A4), acetone 8 hrs (A8) and hexane 8 hrs (H8) as a control. Next, the oxidative stability and antioxidant activity of chia seed oils stored at different temperatures (25°C and 40°C) for 18 days were evaluated. From the study, chia seed oil (A8) had the highest content of α-linolenic acid (67.79%) with significant difference (p < 0.05) followed by other oil samples that were extracted using acetone and hexane for 4 hrs (67.54%) and 8 hrs (66.38%), respectively. The oxidative stability of chia seed oil was determined by peroxide value, p-anisidine value and TOTOX value. The results revealed that chia seed oils stored at room temperature (25°C) had higher oxidative stability compared to oil samples stored at 40°C. Elevated temperature strongly affected lipid oxidation. The control sample had higher oxidative stability than acetone-extracted chia seed oils. Meanwhile, antioxidant activity using DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity test was also carried out. Antioxidant activity of chia seed oil extracted by acetone had higher radical scavenging activity inhibition (p < 0.05) than the control sample at both temperatures (25°C and 40° C).The results confirmed that chia seed oil obtained by acetone had higher polyunsaturated fatty acids and lower oxidative stability than hexane. In conclusion, chia seed oil extracted by hexane showed better oxidative stability at different storage temperatures.

The aim of this study is to investigate the ability of acetylcholinesterase from fresh water carp,Osteochillus hasseltias an assay to detect insecticides.The IC50 values for the carbamates, carbofuran, carbaryl, methomyl, bendiocarb were 0.0550, 0.0497, 0.0845, 0.0470μg/l,respectively, and the IC50 values for the oxonated organophosphates parathion, malathion, diazinon and chlorpyrifos were 0.0660, 0.0681, 0.0991 and 0.0632μg/l, respectively. The carbamates carbaryl, and the oxonated organophosphate diazinon showed lower IC50s in O. hasselti compared to E. electricus while parathion and diazinon showed similar sensitivity to E. electricus. Carbofuran, methomyl, bendiocarb and malathion exhibited lower IC50 confidence interval in E. electricus than in O. hasselti. This suggests that in overall, AChE from Osteochillus hasseltiis a suitable source of enzyme for the detection of insecticides.

The application of enzymatic peeling technology aided with vacuum infusion has been studied extensively in this study to ease the peeling process of key lime (Citrus aurantifolia) fruit. Through response surface methodology, the optimum parameters such as vacuum pressure (450-600 mmHg), pectinase concentration (0.5-1.0%, v/v), duration of soaking time (15-45 min) and their efects on physicochemical properties of key lime fruit have been determined. The optimal conditions determined in this study were 600 mmHg of vacuum pressure, 0.93% v/v of pectinase concentration and 45 min of soaking time. The physicochemical properties analysed such as colour, pH, titratable acidity, total soluble solids, moisture content, and ascorbic acid content show no signifcant (p>0.05) efect of enzymatic-peeling on quality parameters of key lime fruit products. The intensity of puree colour was signifcantly (p≤0.05) improved by the vacuum-aided enzymatic treatment. Overall, vacuum-aided enzymatic treatment is an improved peeling method compared to the conventional method as it simplifes the process, reduces processing time and retains quality parameters of the key lime fruit products.

High rice production produces a high amount of waste, especially rice bran (~10%), suitable as cooking oil. This study was performed to investigate the rice bran dried at different temperatures and times for stabilization treatment and the oil extracted using Soxhlet and Ultrasonic-assisted extraction (UAE). The rice bran produced the highest oil yield (31.9%) and β-carotene (7.82%) than control after stabilized at 50 ºC for 1 h. Unstabilized rice bran (control) and stabilized rice bran (50 ºC for 1 h) were used to compare the changes in viscosity, oxidative stability and fatty acids composition of the extracted oil using Soxhlet and UAE. The rice bran oil's viscosity obtained by stabilization and different extraction methods were decreased compared to the non-stabilized treatment. Meanwhile, stabilized rice bran oil extracted by the Soxhlet method produced higher oxidative stability than the control for both extraction methods due to the low amount of unsaturated fatty acids. Therefore, the Soxhlet extraction method had more stable rice bran oil than the UAE process, and selected parameters (50 ºC for 1 h) for stabilization treatment are the most suitable for reducing rice bran oil oxidation.