Megabiodiversity of Malaysian’s flora and fauna which include microorganism could be conserved and served as alternative source indigenous yeast, the leavening agent of commercial bread making. This study was conducted in attempt to exploit the potential of Saccharomyces cerevisiae strains isolated from 30 different local fruits and plant parts as a leavening agent in bread making. The enrichment was carried out by fermenting the plant samples in medium containing Grape Must at 25°C for 10 days following by isolation of tentative yeasts at 30°C for 3 to 5 days. 20 out of 30 samples tested showed the presence of yeasts was then selected for identification of S. cerevisiae strains through biochemical and physiological tests. Of the 20 yeast strains examined, 13 strains were identified as S. cerevisiae and potentially used as leavening agent in bread making where 5 strains namely SN3, SMK9, SDB10, SRB11 and SS12 showed better fermentative performance compared to commercial strains. Thus, indicated that the local fruits and plant parts could be the potential source of indigenous S. cerevisiae strains for leavening agent in bread making.
Young and mature leaves of Terminalia catappa of alcoholic and aqueous extracts were evaluated for in vitro antibacterial activity against Vibrio sp. isolated from aquatic animals. Young leaves of T. catappa showed higher antibacterial activity when compared to mature leaves against Vibrio parahemolyticus, with methanolic and aqueous extracts exhibited the largest inhibition zones, 23 and 24 mm, respectively as determined by disc diffusion technique. Ethanolic extract of young leaves showed the lowest MIC and MBC at 3.13 mg/ml and 6.25 mg/ml, respectively. Both alcoholic and aqueous extracts of young and matures leaves exhibit variations in protein, RNA as well as pyrine and pyrimidines leakage of Vibrio sp. Cell membrane disruption is proposed as the mechanism of action of T. catappa leaves extract against Vibrio sp.
Dough mixing and thermal properties including the pasting profiles of various commercial wheat flour (WF)-banana pseudostem flour (BP)-hydrocolloid blends were determined using a farinograph, differential scanning calorimetry (DSC) and a rapid-visco analyser (RVA). The prepared blends were WF, WF substituted with 10% BP (10BP) and 10BP with added 0.8% w/w (flour weight basis) xanthan gum (XG) or sodium carboxymethylcellulose (CMC) (10BPX and 10BPC, respectively). The dough of 10BP and the doughs containing XG or CMC reduced stability and breakdown time compared with the WF dough. All dough containing BP demonstrated greater water absorption and mixing tolerance index values than the WF dough. The substitution of 10% BP into WF and the addition of hydrocolloids did not significantly affect the conclusion temperature (Tc) of the mixture, but did increased the onset temperature (To), peak temperature (Tp) and decreased the gelatinisation enthalpy change (ΔHg) of the blends. Samples of 10BP, 10BPX and 10BPC significantly decreased (p
Different heat treatments, (1) chilled, 4°C (2) boiled at 100°C for 30 min and (3) autoclaved at 121°C at 15 psi for 20 min were employed on goat meat to mimic domestic and industrial cooking. The effects on intensity of actin proteins was observed using two-dimensional gel electrophoresis where significant differences (p>0.05) were observed in the spot intensity between chilled and boiled samples, similarly in chilled and autoclaved samples. However, no significant difference was observed between boiled and autoclaved samples. The slight changes observed in the cooking of meat confirmed that actin protein is susceptible to denaturation cause by heat. MALDI-TOF/TOF analysis revealed the peptide-mass fingerprint between positions 21 – 374 that not affected by heat treatment. Peptides from this position merit the candidature of actin as putative thermostable marker for detecting goat meat (chevon) in food product.
The properties of collagens from Barramundi (Lates calcarifer) skin obtained by acid solubilized (control), pepsin and papain aided extractions were investigated. The yields of collagens (dry weight basis) for acid solubilized, pepsin and papain aided extractions were 8.1, 43.6 and 44.0%, respectively. The collagens were generally colorless although collagens from the enzymes aided-extractions were slightly darker. Based on the e-nose evaluation, the collagens were considered odorless. The pH of all the collagens was in the vicinity of 3; however, those extracted with papain had significantly higher pH. The polypeptide profiles obtained in the SDS-PAGE analysis for pepsin extracted collagen were similar to those of acid solubilized collagens. Papain extracted collagen had distinctly different SDS-PAGE pattern. All the extracted collagens were of type 1 with apparent peptides molecular weight distribution of 37 to 250 kDalton. They had high solubility in pH 2 to 5 and increasing NaCl concentration up to 6%.
There are many factors influencing the stability and color variation of natural colorant anthocyanin and pH is among the most significant factor. This study aims to determine the stability of the anthocyanins in freeze-dried Hibiscus sabdariffa, Melastoma malabathricum and Ipomoea batatas in various acidic pH (pH 2.0, 2.5, 3.0, 3.5, 4.0 and 4.5). Total monomeric anthocyanin, degradation index, color density and percent polymeric color were analyzed to determine anthocyanins degradation and their color variations. Among the samples, H.sabdariffa contain the highest monomeric anthocyanins (163.3 mg/L) followed by M. malabathricum (49.9 mg/L) and the lowest is I.batatas (13.8 mg/L). Monomeric anthocyanins from I.batatas were found to be very stable and not affected by changes in pH than in H. sabdariffa and M. malabathricum. However, degradation index (DI) of H. sabdariffa was the lowest with value of 0.365 ± 0.049 at pH 3.5. The lowest percentage of polymeric color (4.94 ± 0.64) was also shown by H. sabdariffa at pH 2.5 and maintained a deep red color with increasing pH indicating higher color stability compared to M. malabathricum and I. batatas. Overall, natural pigment in H. sabdariffa was found to be the most stable in both monomeric anthocyanin content and chromaticity properties. These results provided information that will further proven the potential usage of H. sabdariffa, M. malabathricum and I. batatas as natural coloring agents to replace the synthetic colorant in food and beverage industries.
Consumption of dietary fibre-rich food has been associated with various beneficial physiological properties and health effects. Presently, different types of natural fibre-rich ingredients are added into variety of bakery-based products to improve it fibre content for health promotional purposes. However, majority of these products are frequently added with imported dietary fibre ingredients. In the present study, bread samples were prepared with Zea mays ear (young corn) powder at the levels of either 2%, 4% or 6%. The bread samples were analyzed for nutritional composition, textural properties and sensory acceptance. Addition of young corn powder (YCP) at the level of 6% increases total dietary fibre (from 3.48% to 5.26%), moisture (from 25.64% to 26.55%), fat (from 4.35% to 4.61%) and protein content (from 9.13% to 9.51%) significantly. However, with the increasing of YCP levels in the bread, the carbohydrate content was decreased significantly (from 59.93% to 58.34%) while the ash content (from 0.95% to 0.99%) was not significantly affected. Results of texture profile analysis indicated that addition of YCP up to 6% not significantly affected the springiness (1.01-1.00) but significantly decreased cohesiveness (0.95-0.82). However, the addition of YCP up to 6% has increased hardness (0.18kg-0.57kg), gumminess (0.17kg-0.47kg) and chewiness (0.18kg-0.47kg) attributes of bread samples. On the other result, the sensory evaluation shows that the flavour score was not significantly affected by addition of YCP up to 4% (4.82-4.52) while the tenderness (4.53-4.42), elasticity (4.75-4.58), aroma (4.40-4.47), colour (4.93-4.55) and overall acceptance (4.80-4.35) scores were not significant affected up to 6%. In summary, breads with 4% addition of YCP were considered to be acceptable and potentially used in improving nutritional composition without changing sensory score.
Extensive use of synthetic-based polymer plastic as packaging medium to pack food products has led to serious environmental problems due to their total non-biodegradability property. The stability of nutritional composition and physical traits of chicken patties containing oyster mushroom packed with biodegradable and non-degradable packaging materials were studied. The chicken patties containing oyster mushroom were packed with either biodegradable plastic (BP), paper box (PB) or non-biodegradable high density polyethylene (HDPE). Generally, there were no significant (P>0.05) different in all nutrient analyzed except for carbohydrate after 6 months of storage for chicken patties packed with different types of packaging. The chicken burger packed with both BP and PB packagings were able to retain the moisture and fat without jeopardizing the diameter reduction and cooking yield during storage. There were no differences in all nutrient analyzed after 6 months of storage of chicken patties packed with either biodegradable packagings (BP and PB) or non-degradable packaging. In addition, frozen storage does not significantly affect the concentration of of β-glucan in both BP and PB packagings. In summary, these results indicate that biodegradable packagings applied in packing chicken patty frozen for 6 months were effective in controlling the microbial growth and provide wholesomeness and safety to the chicken patty containing oyster mushroom.
Texture and biochemical changes, specifically in moisture, protein content and amino acid profile were studied throughout the molt cycle of Panaeus monodon. This study was initiated to investigate changes that may occur in mass and tissue composition during different molting stages. Molting of Penaeus monodon are classified into 3 main stages; postmolt, intermolt and premolt. Result of biochemical analysis, shows that moisture varies from 78.02-80.88%, indicating a maximum value during postmolt and minimum value during premolt. Total protein content was found to be higher during intermolt (23.48%) and postmolt (22.27%) compared to premolt (23.10%). The result of SDS-PAGE electrophoresis shows a higher intensity of protein band during intermolt which corresponds to higher protein content. Thus, this electrophoresis method is useful as an alternative to determine different stages of shrimp molting. This is based on intensity of the protein band which is referring to protein content of the shrimp at its different stages. The amino acid profile showed that arginine, alanine, glutamic acid, glycine, lycine, and thronine increased during premolt whilst isoleucine and phenylalanine higher during postmolt. Aspartic acid and histidine was higher in intermolt than in premolt and postmolt. Texture analysis carried out give an elastic modulus value that is high during premolt compared to postmolt and intermolt. There are significant changes in texture and biochemical composition through elastic modules value and protein composition of Penaeus monodon during each stages of moltcycle.
This study was conducted to investigate and compare the fatty acids and tocopherols of lipid extracted from marine microalgae, Nannochloropsis oculata (NO) and Tetraselmis suecica (TS) using solvent extraction and supercritical fluid extraction (SFE). Fatty acids and tocopherols were determined in the extracted lipid as functions of the temperature (40, 80oC) and pressure (3000, 5000, 7000, 9000psi). Dichloromethane/methanol and hexane were the chosen conventional solvent for fatty acids and tocopherols extraction respectively. The results obtained showed that there were differences in the fatty acid composition of various lipid extracts of NO and TS. Extracts of NO were high in myristic acid (C14:0) (17-35%), palmitic acid (C16:0) (14-47%) and palmitoleic acid (C16:1) (11-42%) whereas extracts of TS were high in C14:0 (21-34%) and C16:0 (29-49%). Eicosapentaenoic acid (EPA) was detected only under certain SFE conditions in NO but was not detected in TS. α-, β- and γ-tocopherol were detected in various SFE extracts of NO but only α- and β-tocopherol were detected in TS. Hexane extraction of both NO and TS resulted in the detection of only α-tocopherol. In conclusion, the use of different extraction methods resulted in different compositions and concentrations of fatty acids and tocopherols in the microalgae studied.
With the concern of adverse effects of lipid oxidation on food deterioration and human health, the antioxidant activities of kenaf seed extracts (KSE), roselle seed extracts (RSE) and roselle extracts (RE) were evaluated by comparing its oxidative stability in refined, bleached & deodorised (RBD) sunflower oils with that of in synthetic antioxidant, BHA. Established methods such as peroxide values (PV), p-anisidine values (AV), TOTOX values, free fatty acids (FFA), iodine values (IV), total phenolic contents (TPC), conjugated dienes (CD) and conjugated triene (CT) were employed to assess the extent of oil deterioration. During 24 days storage, consensus was accomplished based on the results assessed by PV, TOTOX, CD, CT, IV and TPC at which the antioxidant activities of KSE, RSE and RE were better than BHA. Surprisingly, the results obtained by AV and FFA assays showed the reversed. Among the extracts, RSE exhibited the best antioxidant activities. These suggest that KSE, RSE and RE may be used as potential source of natural antioxidants in the application of food industry to prevent lipid oxidation.
Vitamin E is known to have potent antioxidant activity and plays an important role in reducing oxidative stress, a pivotal step in atherogenesis. However, several randomised clinical trials using α-tocopherol have failed to demonstrate consistent beneficial effects of antioxidants against atherosclerosis and clinical endpoints. Tocotrienol, a vitamin E compound analogue is shown to have more potent antioxidant activity compared to tocopherol. Finding the optimal anti-oxidative dose is crucial and may effectively be applied for cardioprotection in human. The objective of this study was to determine the optimal dose of tocotrienol rich fraction (TRF) with highest antioxidant activity in vitro using the ferric thiocyanate (FTC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and 2’, 7’- dichlorofluorescein diacetate (DCFHDA) assays. It was found that TRF exhibited potent antioxidant and free radical scavenging activities with an IC50 of 22.10 + 0.01 µg/ml. In all assays, TRF had optimal antioxidant activity at moderate concentrations (10-100 µg/ml). In conclusion, TRF has potent antioxidant activity, which is optimal at moderate concentrations.
The aim of this study is to determine the antioxidant capacity of underutilized fruits in Malaysia namely Milk apple (Syzygium malaccense), Malay apple (Syzygium malaccense (L.) Merr. and Perry), and Water apple (Syzygium aqueum). Synthetic antioxidants (BHA and BHT) commonly used in the food industries may not be as safe as it was presumed earlier. As BHA and BHT may be carcinogenic, it is important to look for new sources of natural antioxidants from fruits and vegetables. Freeze dried samples extracted with acetone and water were measured by ferric 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and Ferric Reducing Antioxidant Power (FRAP) assays. Acetone extract (50%) showed higher values for both DPPH and FRAP assays compared with water extract. Milk apple has the highest DPPH value of 95.26% inhibition of DPPH. Milk apple also showed the highest FRAP value with 8722.22 µM of Fe (II) per gram of freeze dried sample. There was a significant difference (P < 0.05) in the types of extraction used. Antioxidant capacities of the samples are in the following order: Milk apple > Malay apple > Water apple. Proximate compositions and mineral contents of the samples were determined too. The samples can be used as a source of natural antioxidants.
Antioxidant properties of both fresh and convection oven-dried guavas (Psidium guajava L.) were determined. Guava slices of 1.0 cm wide, 3.0 cm long and 0.5cm thick (20 g) were subjected to convection drying at 40°C for 9, 12 and 14 hours, respectively, and their water activity, total phenolic content (TPC) and antioxidant activities were measured. Guavas that had been subjected to drying for 9, 12 and 14 hours were shown to achieve the water activity of 0.36-0.49. Ascorbic Acid Equivalent Antioxidant Capacity (AEAC) of guava was found to decrease for all the drying durations. Convection oven-drying of guava for 12 and 14 hours showed a significant decrease in TPC (p < 0.01) and Ferric Reducing Power Assay (FRP) (p < 0.01). Nine hours of convection oven-drying was shown to retain most of the TPC, AEAC and FRP of guava.
In the last decade, non-thermal processing for inactivating microorganisms has been developed in response to the worldwide interest for more fresh and improved quality of food products. Winter melon is a very perishable fruit, hence, processing into puree is a necessity. However application of heat in the production of puree could affect the nutritional values, thus, application of non thermal treatment in combination with preservation method is significant for this fruit. This study was conducted to evaluate the effect of non-thermal processing in combining with preservation method on antioxidant activity, level of key antioxidant groups (total phenolic and ascorbic acid content) and the color of winter melon puree. Total phenolic content (TPC) was measured using Folin-Ciocalteu reagent. Ascorbic acid (AA) was determined using 2,6-dichlorophenol-indophenol titration method. Antioxidant activity were determined using four antioxidant assays namely Ferric Reducing Antioxidant Potential (FRAP), Oxygen Radical Absorbance Capacity (ORAC), 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) and β-Carotene Bleaching Assays. For the TPC, puree with pH 3 (28.5±1.3 GAE/g fresh weight) exhibited high in TPC as compared to puree with pH 3.5 and unprocessed puree. In contrast, unprocessed puree contains significantly high ascorbic acid (AA) content (35.9 ± 1.8 mg/100 g fresh mass) as compared to pH 3.0 and pH 3.5 purees. In general, antioxidant activity for all assays of pH 3.0 and pH 3.5 purees were significantly higher (p
The spray-dried Vernonia amygdalina water extract was evaluated for antidiabetic effect using normoglycaemic, glucose induced hyperglycaemic and streptozotocin induced diabetic mice. This effect was compared with an oral dose of Momordica charantia. Besides, acute toxicity of the extract was also evaluated at concentration 2000 and 5000 mg/kg body weight. The extract was able to reduce blood glucose level in glucose and streptozotocin induced hyperglycaemic mice without causing hypoglycemic effect on fasting normoglycaemic mice. Moreover, mice appeared to be normal and no mortality was observed in the acute toxicity study after treated with up to 5000mg/kg of extract. These results indicated that the spray-dried Vernonia amygdalina water extract was a potential antidiabetic agent which does not induce hypoglycemic and acute toxicity on normal subject.
Plants, particularly fruits and vegetables, have many phytochemicals that possess various bioactivities, including antioxidant and anticancer properties. In this study, the aim was to investigate the antiproliferative properties of Syzygium fruits, namely water apple (Syzygium aqueum), milk apple (Syzygium malaccense), and malay apple (Syzygium malaccense L.) against two types of cancer-origin cells, namely MCF-7 (hormone dependent breast cancer cell line) and MDA-MB-231 (nonhormone-dependent breast cancer cell line). Two solvent methods were prepared using aqueous and methanol extraction. Antiproliferation activities of these extracts were evaluated by employing colorimetric MTT (3-(4,5-dimethylthiazol-2-yl)2,5 diphenyltetrazolium bromide) assay through time periods of 24, 48, and 72 hours. The result showed that extracts from the three fruits had no significant effects for 24 and 48 hours time periods (p >0.05) but extracts of Water apple and Malay apple displayed antiproliferation effects on MCF-7 cell lines (p
Duck feet collagen was added to threadfin bream and sardine surimi to study its effect on physicochemical properties such as folding test, gel strength, cook loss, water holding capacity, expressible moisture, texture profile analysis and colour measurement. As compared to commercial fish scale collagen and cow collagen, the addition of duck feet collagen resulted in a significant improvement in the quality of the sardine surimi. Duck feet collagen was able to improve the folding test score of sardine surimi from 3.00 to 5.00; gel strength was increased from 275.70 g.mm to 2682.70 g.mm and hardness of gel was increased from 1.12kg to 6.00kg. Addition of duck feet collagen improved the gel strength of threadfin bream surimi from 1696.70 g.mm to 5579.40 g.mm and hardness of gel was increased from 4.55kg to 10.32kg. Colour of threadfin bream and sardine surimi also improve with the addition of duck feet collagen. The lightness was increased from 66.47 to 66.89 (threadfin bream) and from 62.32 to 63.60 for sardine. The results suggest that duck feet collagen has potential as an alternative source of protein additive for the improvement of the physicochemical properties of low grade surimi.
Cantaloupes continue to ripen after harvesting which is caused by ethylene production due to climacteric behaviour during postharvest storage. In this study, the cantaloupe fruits harvested at commercial maturity were evaluated for quality attributes during three weeks of storage at 10°C and a relative humidity (RH) of 90±5%. In addition, fresh-cut samples were stored for a further 19 days at 2°C and 87% RH. The fresh-cut samples were prepared on a weekly basis by dipping into deionised water (control) at 2°C for 1 minute. The effect of postharvest storage of cantaloupe on the physico-chemical properties and microbial activity was observed prior to fresh-cut processing. It was found that firmness, luminosity (L*), and titratable acidity (TA) decreased, while total soluble solids (TSS), pH, TSS:TA ratio, microbial activity (total plate count (TPC) and yeast and mould (YM)) of the fresh-cut increased over the postharvest storage period of the fruit. Meanwhile, the orange colour and the intensity (hue angle, hab, and chromaticity) of the flesh did not differ significantly during storage. The cantaloupe stored for three weeks at a low temperature indicated a successful potential for fresh-cut processing due to good maintenance of the product quality.
This study was done to assess the total phenolic compounds (TPC) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity in the flowers and leaves of Clitoria ternateaand Vitex negundo Linn. by using methanol and water extraction. TPC were evaluated using Folin-Ciocalteau method. Methanol was more efficient in extracting phenolic compounds compared with water in measuring TPC. Vitex negundo Linn. contained higher amount of TPC compared to Clitoria ternatea. Besides that, leaves for both plants showed higher amount of TPC compared to the flowers. Methanol extracted Vitex negundo Linn. showed higher DPPH scavenging activity compared with Clitoria ternatea. In contrast, DPPH scavenging activity for water extracted Clitoria ternatea showed higher value in compare with water extracted Vitex negundo Linn. The type of solvent used to extract the plant material and concentration of extracts used showed significance difference (P < 0.05) on the amount of DPPH scavenged by the plant extract. The presence of antioxidant activity in both leaves and flowers showed that Clitoria ternatea and Vitex negundo Linn. have the potential to be an alternative source of natural antioxidants. In vivo study is needed for successful commercialization and to benefit both the food and pharmaceutical industries.