This study aimed to compare the antioxidant content and antioxidant capacity of pulp and peel of two varieties of pomelo fruit (Tambun White and Tambun Pink). Antioxidants including total phenolic content, total flavonoid content and ascorbic acid content were determined using Folin-Ciocalteu reagent assay, aluminium chloride colorimetric assay and AOAC method, respectively. Antioxidant capacity of pomelo pulp and peel was measured using ferric reducing antioxidant potential and trolox equivalent antioxidant capacity assays. The peels of both pomelo fruits had higher antioxidant content and capacity than their pulps. Moreover, the white variety of pomelo had higher antioxidant content and capacity compared to the pink counterpart. Trolox equivalent antioxidant capacity of the samples was positively high correlated with total phenolic content (r = 0.978) and total flavonoid content (r = 0.959), except for ascorbic acid. Therefore, pomelo peel from white variety possessed higher antioxidant properties and it is potentially rich sources of natural antioxidants.
Papaya (Carica papaya L. cv. Hongkong) is an economically important fruit crop grown in Malaysia. During its ripening stages, (C. papaya L.) exhibits different physicochemical properties, antioxidant capacities, and sensory quality results. The objective of this study was to elucidate in detail the antioxidant capacity of C. papaya as determined by total phenol content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP),2,2-diphenyl-1-picrylhydrazyl (DPPH) and scavenging systemand (ABTS). The study also aimed to study physicochemical changes of papaya fruits based on measured pH, titratable acidity (TA), total soluble solids (TSS), moisture and fruit color at five different stages of ripening. The fruits were harvested at five different, stages RS1, RS2, RS3, RS4, and RS5 corresponding to 12, 14, 16, 18, and 20 weeks after anthesis, respectively. Significant differences were found at different stages of ripening. The pH of the fruit decreased significantly (P < 0.05), whereas TA, moisture, and TSS increased significantly (P < 0.05) during the ripening process. The redness (a*) and yellowness (b*) values of fruit color both increased significantly (P < 0.05), whereas
lightness (L*) varied. The total phenol content TPC, TFC, FRAP, DPPH and ABTS values increased significantly (P < 0.05) with the ripening process. Sensory evaluation based on the color, sweetness, sourness, flavor, and overall acceptance for the last three maturity stages was also performed. RS5 had a better score than RS3 or RS4. The results showed the important role of the ripening stage in increasing the antioxidant content of papaya fruits.
Central Composite Design (CCD) was used to optimize roasting conditions (temperature and
time) for Arabica coffee beans. Current method of roasting was able to give good quality beans
in term of flavour but the formation of acrylamide was not studied. In this study, optimization
based on high quantity of flavour compounds (pyrazines) with low level of acrylamide resulted
in roasting temperature of 167ºC for 22 minutes. The coffee beans produced using the optimized
conditions have the following characteristics: flavour compounds: 2,3,5 trimethyl pyrazine (0.48
mg/100 g), 2,3,5,6 tetramethyl pyrazine (0.42 mg/100 g), 2 methyl pyrazine (0.25 mg/100 g)
and 2,5 dimethyl pyrazine (0.13 mg/100 g) and low concentration of acrylamide (0.11 mg/100
g) with sensory evaluation of 7.5 from 10 points. This proposed roasting condition will be very
useful for coffee manufacturers in order to produce high quality coffee beans.
Antioxidant capacity of Ocimum tenuiflorum L. or ‘ruku’ were determined in this study. Fresh
leaves of Ocimum tenuiflorum was subjected to freeze drying, vacuum drying and processed
into fermented and unfermented tea. The samples were extracted using distilled water and the
total phenolics, total flavonoids, condensed tannin content, anthocyanins and total antioxidant
capacity (TAC) were assessed, measured with ferric reducing antioxidant power (FRAP)
and 1,1-diphenyl-1-picrylhydrazyl radical scavenging capacity (DPPH) assays. The results
showed that drying the fresh leaves of Ocimum tenuiflorum and processing them into tea leaves
significantly increase (P < 0.05) the antioxidant capacity, total phenolic content, total flavonoid
content, and condensed tannin content. However, anthocyanins content showed reduction
after drying. In the present study, it can be concluded that the vacuum drying method seem
to produce a product with higher quality of antioxidant properties than freeze drying. Hence,
vacuum drying can be used to replace freeze drying as it is also cheaper than freeze drying.
The effect of the addition of different concentrations of chitosan (0–2.0% w/w) on the gelling properties of surimi gels made from African catfish (Clarias gariepinus) was tested. Lipid oxidation, total volatile basic nitrogen (TVB-N), and aerobic plate count (APC) changes during 20 days of storage at 4oC also were evaluated. Surimi gels with 1.5% (w/w) chitosan added exhibited the highest improvement in gel strength (58.92%), whiteness (13.18%), and water holding capacity (36.8%). Incorporation of 2.0% (w/w) chitosan in gels resulted in the lowest TVB-N value (36.63 mg N/100 g) at the end of the 20 days storage period. Both the peroxide values and the 2-thiobarbituric acid values increased more slowly in the chitosan-treated gels than in the control gel during the storage period. Chitosan at concentrations of 1.75% and 2.0% (w/w) conferred the best antioxidant effect on catfish surimi gels and resulted in a significant reduction in APC. Based on the microbiological acceptability limit (106 cfu/g), the shelf life
of surimi gels with 1.75% and 2.0% (w/w) chitosan was extended to 12 days in refrigerated storage at 4oC, whereas the other samples lasted only 8 days. Hence, the addition of 1.5–2.0% (w/w) chitosan is a promising approach for the preparation of catfish surimi gels, as it improves texture, prevents lipid oxidation, and inhibits microbial growth.
Five improved Nigerian barley cultivars (ESCOBA, ASE – 2, ALOE, GOB – 2, SUMBARD) were obtained from Lake Chad Research Institute Maiduguri, Nigeria, and their physicochemical, malting and biochemical properties investigated employing standard procedures. Data were analyzed by means of ANOVA [at 95% significant level] and correlations using SPSS 14 software. Results showed GOB-2 grain and malt recording the highest kernel weight (47.50 g) and kernel volume (41.21 ml); whereas ALOE grain had the longest kernel length (13.40 mm) and GOB-2 the shortest (9.40 mm). GOB-2 had the largest major diameter (3.39 mm) and SUMBARD had the least (2.86 mm). ESCOBA, SUMBARD and ASE-2 cultivars had the highest protein values (as %N) of 14.90%, 13.90% and 13.69% respectively, while ALOE, ASE-2 and GOB-2 had the highest total carbohydrates of 69.97, 69.39 and 68.90% respectively. All the cultivars had good germinative capacities (> 90%), with GOB-2 and ASE-2 having the highest germinative energy values of 96.65% and 95.00%. No significant (p > 0.05) changes
in the dimension of the kernels after malting. SUMBARD recorded the highest malt yields (88.55%) followed by ASE-2 (83.45%) and ALOE (82.00%). The highest α-amylase activities of 105.34 and 96.23 unit/mg protein/min were recorded by ASE-2 and ALOE, respectively, with corresponding diastatic powers of 81.92 and 76.23oL. Thousand kernel weight correlated positively with protein (r = 0.500, P < 0.05) and with total soluble solids (r = 0.435, p < 0.05) but negatively with α-amylase (r = -0.869, p < 0.05) and with diastatic power (r = -0.838, p < 0.05). This study showed that the cultivars have good potentials for use as malting materials in beverage making.
MeSH terms: Academies and Institutes; Aloe; alpha-Amylases; Amylases; Analysis of Variance; Hordeum; Beverages; Body Weight; Carbohydrates; Edible Grain; Chad; Nigeria; Software; Overweight; Lakes
The objective of this work was to study the effects of trehalose and maltodextrin on Chinese
steamed bread (CSB) prepared from frozen dough. Trehalose (0.1 and 0.2% w/w) and
maltodextrin (1 and 2% w/w) were added and CSB prepared from the fresh dough and the
frozen dough was characterized in terms of spread ratio, specific volume, staling index and
stress relaxation properties. Upon frozen storage, spread ratio and specific volume of CSB,
and elasticity of the bread crumb were reduced. The extend of deterioration was significantly
reduced with the addition of 0.1% trehalose and 2% maltodextrin. Excessive addition of
trehalose and maltodextrin was found to cause detrimental effects to CSB quality.
This article summarises the current methods for total malachite green (MG) detection which is known as a sum of MG and leuco-malachite green (LMG) that has been used extensively in aquaculture as fungicide, dye color in textile and other purposes in food industries. LMG is a reducing form of MG, where the MG is easily reduced due to the photo-oxidative de-methylation process. Nevertheless, the use of MG had become an issue due to its toxicity effects. Many analytical instruments such as HPLC, LC—MS/MS, GC—MS, and spectrometry have been widely used for detection of MG. However, these methods require long time sample preparation and analysis, expensive, use hazardous reagents and indirect measurements. Hence, other analytical methods which are more sensitive, safe, rapid, inexpensive and portable are required. Alternatively, biosensors promise a more sensitive and rapid detection method for MG and LMG.
MeSH terms: Chromatography, High Pressure Liquid; Chromatography, Liquid; Indicators and Reagents; Methylation; Rosaniline Dyes; Spectrum Analysis; Textiles; Biosensing Techniques; Aquaculture; Food Industry; Tandem Mass Spectrometry
The physicochemical properties of silver catfish frame hydrolysate powder at three different degree of hydrolysis, DH43%, DH 55% and DH 68% were studied. The hydrolysates powder were obtained by hydrolysis using Alcalase®, centrifugation and spray drying of the supernatant. The study found that preparation of these hydrolysates affected the protein, ash and fat content as well as amino acid composition. As for essential amino acids, their values were generally considered as adequate as compared to the suggested essential amino acids profile of FAO/WHO. The results showed that SFHs were rich in lysine and glutamate. Hydrolysate at DH 68% exhibited better peptide solubility and water holding capacity. As degree of hydrolysis increased, emulsifying capacity and foaming capacity of the hydrolysate decreased. It was also found that the lightness in hydrolysate powder decreased with increase in degree of hydrolysis. This study shows that silver catfish frame hydrolysate has good solubility, good foaming properties and light colour profile, thus having high potential as food ingredient.
Aqueous and methanol extracts of the flowers of Clitoria ternatea (CT), a popularly
plant consumed for blue colour in Nasi Kerabu was selected to explore its cytotoxic
effect on six types of normal and cancer-origin cell lines. These included the hormone-dependent breast cancer cell line (MCF-7), non-hormone-dependent breast cancer cell
line (MDA-MB-231), human ovary cancer cell line (Caov-3), human cervical cancer cell line (Hela), human liver cancer cell line (HepG2) and human foreskin fibroblast cell line (Hs27). The anti-proliferation activities of the extracts were examined by employing colorimetric MTT (3-(4,5-dimethylthiazol-2-yl) 2,5 diphenyltetrazolium bromide) assay through time periods of 24, 48 and 72 hours. Preliminary results showed that the water extracted of CT had significant effects (p < 0.05) against MCF-7 with an IC50 value of 175.35 µg/ml. Furthermore, the aqueous and methanolic extracts were investigated by Gas Chromatogram-Mass spectrometry (GC-MS). The GC-MS chromatogram analysis of the water extracted had shown five peaks that represented components in the water extract namely mome inositol (38.7%) and pentanal (14.3%). Fifteen chemical constituents were identified in the methanol extract and the major chemical constituents were mome inositol (33.6%), cyclohexen, 1-methyl-4-(1-methylethylideme)- (7.1%), acetic acid, cyano- (6.5%) and hirsutene (5.7%). Heavy metals tested were at very low levels. The analysis conducted on the flowers provides a strong basis for emphasizing the medicinal and nutritional value of CT.
Traditionally, in Chinese medicine, tree peony and apple flower buds are used to prepare herbal decoctions to cure various ailments. As both of these flowers are popular and used regularly, providing scientific evidence on their basic composition is a necessity. Hence, in the present study, we report the chemical composition of these two flower buds. Results revealed tree peony and apple flower buds to have high crude protein (15.73 and 26.30%), fibre (13.11 and 16.51%), and carbohydrate (57.84 and 40.63%) contents. Both the flowers had significant amounts of essential amino acids and unsaturated fatty acids. Essential minerals present in tree peony and apple flowers were potassium (1540.37 and 1125.60 mg/100 g), calcium (462.46 and 449.98 mg/100 g), magnesium (241.51 and 164.23 mg/100 g), sodium (12.75 and 20.06 mg/100 g), and phosphorus (420.00 and 590.00 mg/100 g), respectively. Heavy metals (cadmium, nickel, mercury, lead, and arsenic) were detected in trace amounts (< 0.50 mg/100 g) in both the flower buds. Results obtained indicate that both flowers could be exploited as an additional source of nutraceutical for the development of new functional foods.
This study was conducted to determine the major potential sources of industrially produced trans fatty acids (IP-TFAs) in Malaysian diet. Levels of IP-TFAs were initially determined in samples (n = 136) collected from 8 food groups (baked products, snacks, dairy products, breakfast cereals, fast foods, semisolid fats and cooking oils, and fried foods). A survey was carried out to 105 subjects aged 19-59 years old to determine the intake of IP-TFAs using Food Frequency Questionnaire (FFQ). The IP-TFAs range from 0-5.79% of food, with the highest found in semisolid fats and cooking oils (0.1-5.79%), followed by fast foods (0.04-0.86%), baked products (0.01-0.29%), breakfast cereals (0.06-0.45%), snacks (0.03-0.26%), dairy products (0-0.26%), and fried foods (0.002-0.06%). A Spearman’s Rho rank test showed that there were significant correlations (p < 0.05) between 4 of the food groups (semisolid fats and cooking oils, fast foods, fried foods, and baked products), with the total IP-TFA intakes of subjects. In general, total IP-TFAs intakes of subjects were < 1% of subjects' diet (0.067%-0.91% of subjects’ total calorie intakes). This indicate that high fat foods (semisolid fats and cooking oils, fast foods, fried foods, and baked products) were the main contributor of IP-TFAs in Malaysian diet, despite the low proportion of trans fatty acids, following their high frequency of daily intake.
MeSH terms: Edible Grain; Cooking; Dairy Products; Diet; Humans; Oils; Surveys and Questionnaires; Trans Fatty Acids; Fast Foods; Breakfast; Snacks
The effects of ethanol concentration (0-100%, v/v), extraction time (60-300 min) and extraction temperature (25-65°C) on the extraction of phenolic antioxidants from Andrographis paniculata was evaluated using single-factor experiments. The following complementary assays were used to screen the antioxidant properties of the crude extracts: total phenolic content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging capacity and 2,2’-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity. The extraction conditions chosen had significant effects (p < 0.05) on the extraction of phenolic compounds and antioxidant capacity. The optimal conditions were 60% ethanol for 60 min at 65oC for phenolic compounds and at 25oC for antioxidant capacity. Strong negative significant (p < 0.05) correlations were observed between the phenolic compounds (TPC, TFC and CTC) and antioxidant capacity comprising ABTS (-0.924, -0.909, -0.887, respectively) and DPPH radical-scavenging capacities (-0.992, -0.938, -0.928, respectively) were determined under the influence of extraction temperature.
Consumption of mushroom has increased remarkably because of their desirable aroma, taste and high nutritional content. This study was undertaken to measure and compare the antioxidant activity, total phenolic content (TPC) and total flavonoid content (TFC) of Agaricus bisporous (white button mushroom) and Agaricus brasiliensis (Brazilian mushroom) in aqueous and 60% ethanol extract. Results showed that button mushroom (21.47 ± 0.48 mg GAE/g of dry weight) had significant higher TPC in aqueous whereas Brazilian mushroom (12.50 ± 0.22 mg GAE/g of dry weight) had significant higher TPC in 60% ethanol (p< 0.05). In terms of TFC, Brazilian mushroom had higher content than button mushroom in both types of solvents. For FRAP assay, Brazilian mushroom had significantly higher total antioxidant activity than the button mushroom in 60% ethanol (p < 0.05) but opposite trend with aqueous. For DPPH radical scavenging activity, Brazilian mushroom (60% ethanol) had the lowest EC50 value, followed by button mushroom (60% ethanol), Brazilian mushroom (aqueous) and button mushroom (aqueous). Pearson correlation test (p < 0.05) showed strong positive correlation between TPC and FRAP assay in both extracts (r = 0.969 for 60% ethanol extract; r = 0.973 for aqueous extract). For TFC, there was a strong positive, correlation with FRAP assay (r = 0.985) in aqueous extract. In conclusion, high antioxidant activity in ethanol extract of mushrooms due to presence of phenolic content can potentially be used as a source of natural antioxidants.
This study aimed to determine and compare antioxidant components and antioxidant capacity in different parts (skin, pulp, mace and seed) of nutmeg. Freeze dried samples were extracted using 80% methanol, while Folin-Ciocalteu assay was employed to determine total phenolic content, aluminium chloride assay was applied to determine total flavonoid content and ascorbic acid was assessed by titrimetric method. Antioxidant activities were evaluated by ferric reducing antioxidant power and trolox equivalent antioxidant capacity (TEAC) assays. Results revealed that nutmeg seed contained the highest TPC followed by mace, skin and pulp. Similar observation was also found for TFC. The highest ascorbic acid content was found in nutmeg mace, while the lowest was in its pulp. For antioxidant activity, nutmeg seed possessed the highest FRAP and TEAC values, while nutmeg pulp had the lowest as compared to other parts. Phenolic compounds in nutmeg samples have exhibited strong correlation with antioxidant capacity. Therefore, nutmeg is a potential functional food with high antioxidants, especially nutmeg seed. Phenolic compounds in nutmeg samples have exhibited strong correlation with antioxidant capacity. Therefore, nutmeg is a potential functional food with high antioxidants, especially nutmeg seed.
This study was conducted to compare the total antioxidant activity (TAA), total phenolic content (TPC) and total flavonoid content (TFC) from the different parts of papaya tree including their ripe and unripe fruit, seeds and the young leaves. Two methods namely DPPH radical scavenging activity and ß-carotene bleaching assay were used to determine the TAA, whereas TPC was determined by Folin-Ciocalteu’s method while TFC by aluminium trichloride (AlCl3). For these purposes, methanolic extracts (80%) were prepared. The results showed that the highest antioxidant activity through ß-carotene bleaching assay was observed in unripe fruit (90.67 ± 0.29%) followed by young leave, ripe fruit and the seed. In other hand, young leaves exhibited a significant higher scavenging effect compared to others and the dose required in reducing the absorbance of DPPH control solution by 50% (EC50) was calculated at 1.0 ± 0.08mg/ml. The EC50 values were 4.3 ± 0.01mg/ml, 6.5 ± 0.01mg/ml and 7.8 ± 0.06mg/ml for unripe fruit, ripe fruit and seeds respectively. Interestingly, both TPC and TFC also showed that young leaves had the highest antioxidant content (424.89 ± 0.22mg GAE/ 100 g dry weight and 333.14 ± 1.03mg rutin equivalent/ 100 g dry weight, respectively). Statistically, Pearson correlation showed there were positive correlations between TPC and TFC with antioxidant activity assayed by DPPH radical scavenging assay (r=0.846 and r=0.873, respectively). However there was no correlation between TPC and TFC with ß-carotene bleaching activity. In brief, taken into account all the parameters measured, antioxidants were highly remarkable in the sequence of young leaves > unripe fruit > ripe fruit > seed. Nevertheless, further investigation for isolation and identification of the phytoconstituents responsible for antioxidant activity is desirable.
Bacillus cereus is a soil inhabitant gram positive bacterium, and is known to cause severe food poisoning. The objective of this study was to isolate and identify the presence of Bacillus cereus s.l. from selected ready to eat cereals purchased randomly from local supermarkets in Kuching and Kota Samarahan, Sarawak. The result showed that four of the 30 food samples were detected to be contaminated by B. cereus s.l. . Our findings suggested that it is important for the public to be aware of the safety of RTE cereals consumption, as it is possible that B. cereus s.l. may be present in high count number and pose hazardous health effects to the consumers.
The organic foods’ market is becoming one of the rapidly growing sections in agricultural economies in the world. During the last two decades, food-borne outbreaks associated with fresh produce have rapidly increased. E. coli O57:H7, the caustic agent of acute hemorrhagic diarrhea and abdominal cramps, is mainly associated with meat and poultry product outbreaks but frequent outbreaks linked to the consumption of vegetables have been reported. The aim of this study was to investigate prevalence of E. coli O157:H7 in some organic foods. A total of 230 organic food samples including four-winged bean, tomato, white radish, red cabbage, chinese cabbage, lettuce, cucumber and chicken form retailed groceries and supermarkets in Malaysia were investigated. Low prevalence of E. coli O157:H7 was detected in organic vegetables and chickens. The estimated quantity of E. coli O157:H7 in all samples ranged from 2400 MPN/g. The overall MPN/g estimate of E. coli O157:H7 in the samples from organic groceries was higher than supermarket with the maximum of >2400 MPN/g. Most of the samples from supermarket showed a minimum of
E. coli O157:H7 is associated with life threatening diseases such as hemorrhagic colitis (HC), hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Raw milk is considered a high risk food as it is highly nutritious and serves as an ideal medium for bacterial growth. The aim of this study was to investigate the prevalence of E. coli O157:H7 in raw cow, goat and buffalo milk samples. MPN-PCR method targeting the major virulence rfbE gene and fliCH7gene of E. coli O157:H7 was used. Total of 177 raw milk samples were collected from local dairy farms in the state of Selangor, Malaysia. The highest prevalence of E. coli O157:H7 was found in raw cow milk (18.75%). E. coli O157:H7 was detected in 7.32% and 3.57% of raw goat and buffalo milk, respectively. The estimated quantity of E. coli O157:H7 in raw cow, goat and buffalo milk ranged from
Listeria monocytogenes (L. monocytogenes) is a serious food-borne pathogen for immunocompromised individuals. L. monocytogenes is capable of producing biofilm on the surface of food processing lines and instruments. The biofilm transfers contamination to food products and impose risk to public health. Transfers contamination to food products, and impose risk hazard to public health. The aim of this study was to investigate biofilm producing ability of L. monocytogenes isolates. Microtitre assay was used to measure the amount of biofilm production by ten L. monocytogenes isolates from minced chicken / meat, sausages and burgers. Results showed that all 10 L. monocytogenes isolates were able to form biofilm after 24 h at 20˚C on polystyrene surface (the common surface in food industries). Some strains were capable of forming biofilm more than the others. All strains showed a slight raise in the quantities of attached cells over 48 and 72 h. L. monocytogenes strains isolated from minced chicken, minced meat and burgers were better biofilm-producers comparing to the strains isolated from sausages.
MeSH terms: Animals; Chickens; Food Handling; Humans; Listeria monocytogenes; Meat; Meat Products; Polystyrenes; Public Health; Biofilms; Food Industry