The objective of this study is to establish conditions that allow optimal yield and antioxidant
activity for Golden Apple Snail (GAS) (Pomacea canaliculata) protein hydrolysate by employing
response surface methodology (RSM). A three level, face-centered, central composite design
(CCD) was adapted to assess the effects of temperature (45–65˚C); pH (8–10); the ratio of
enzyme to substrate (2–4%); and hydrolysis time (60–180 min). The antioxidative activity
of the hydrolysate obtained under optimized conditions was then evaluated via the following
metrics: hydroxyl radical scavenging, reducing power, and chelating effects on ferrous ion.
Established optimal conditions for the enzymatic protein hydrolysis of GAS were a temperature
of 45˚C, a pH of 10, an enzyme concentration of 2%, and hydrolysis time of 159 minutes. The
optimized GAS protein hydrolysate produced an experimental yield of 9.72% and antioxidant
activity of 73.54%—slightly less than the predicted yield of 11.36% and antioxidant activity of
78.88%. The optimized GAS protein hydrolysate formed demonstrated both higher chelating
effects and hydroxyl scavenging activity but had lower reducing power. These results suggest
that GAS protein hydrolysate holds potential as a natural antioxidant for use in food processing.
This study aimed to determine the protective effects of CO pulp and kernel oils supplementation to normocholesterolemic and hypercholesterolemic rabbits. Rabbits from the treatment groups were supplemented with CO pulp and kernel oils for four weeks. Bloods were drawn from all experimental groups at baseline and fourth week to determine protective effects of CO oils supplementation on plasma total antioxidant status (TAS) and catalase (CAT) activity. Liver function tests (ALT, AST, and GGT activities) were also determined for all the groups. The results showed that CO oil supplementation increased plasma TAS in both normal and hypercholesterolemic groups. Plasma CAT activities in the hypercholesterolemic groups supplemented with CO oils were significantly reduced but not for the normocholesterolemic groups. Significant reduction of plasma AST was observed for the hypercholesterolemic rabbits given CO pulp and kernel oils compared with the hypercholesterolemic control rabbits, but not for plasma ALT and GGT. In the normocholesterolemic rabbits, CO pulp oil had caused a significant elevation of plasma ALT, AST, and GGT levels as compared to the negative control rabbits. Therefore, CO pulp and kernel oils are somehow not hepatotoxic, and the oils are potent functional foods.
This study investigated the effect of citric, nitric and sulfuric acid on the yield and
physicochemical properties of pectin extracted from jackfruit and chempedak fruit rinds. Yield
and physicochemical properties such as uronic acid content, degree of esterification, degree of
acetylation and colour of pectin solution were determined and compared. Yield of pectin from
jackfruit and chempedak fruit rinds with nitric acid as extractant were 14.81 ± 1.02% and 17.62
± 0.69%, respectively, which were the lowest. The uronic acid content of all extracted pectin
was more than 65%. All jackfruit and chempedak fruit rind pectins in this study were high
methoxyl pectin with degree of esterification ranging from 72-75% for jackfruit rind pectin and
66-69% for chempedak rind pectin. The degree of acetylation of all extracted pectin was lower
than 1%. For both jackfruit and chempedak fruit rind pectins, the citric acid-extracted pectin
produced darker, more reddish and yellowish solution and thus is least preferable. Among
the acids studied, sulfuric acid was the best extractant due to the high yield of pectin and the
solution of this pectin was brighter, less reddish and yellowish.
The aim of this study was to determine the effects of xanthan gum and carrageenan on the
oil uptake and acceptability of banana (Musa acuminate) fritters during repeated deep fat
frying. Banana namely ‘Pisang Awak’ at maturity stage 6 were peeled, cut and dipped into 3
batter formulations containing 1% carrageenan, 1% xanthan gum and a control. The bananas
were deep fried at 170±5°C for 3 minutes in 2.5L cooking oil without oil replenishment for
3 consecutive days. The moisture, oil content, texture, colour and acceptability of the banana
fritters were evaluated at first and every 10th frying cycles. Results indicated that the oil and
moisture content of fried bananas were dependent on frying cycles. The oil content increased
while the moisture decreased with increased in frying cycles. There was significant reduction
(p0.05) in terms of overall acceptance between
treated and untreated. Hence, 1% xanthan gum was effective in reducing oil absorption of
banana fritters without affecting the overall sensory acceptability
Consumers today prefer to purchase ready-to-eat, fresh-cut fruit that is readily available at the markets and retailers. They generally select the fresh-cut fruit base on the quality, freshness, nutrition and safety. The effects of packaging condition on fresh-cut Cantaloupe were studied during 18 days of storage at 2°C and 87% RH. Fresh-cut Cantaloupe pieces were packed in a Polypropylene (PP) container. As a control, the container was cover with lid without film, while Sample 1 (S1) was sealed only by a 40 μm PP film and Sample 2 (S2) was sealed with a 40 μm PP film and then adding the lid cover. Changes in colour, firmness Total Soluble Solids (TSS), pH, Titratable Acidity (TA) and Total Plate Count (TPC) were evaluated over time. During storage, it was found that the firmness significantly decreased from day 0 until day in all packaging conditions. Color parameters Luminosity (L*) and Chromaticity (C) were significantly change at the significance level of 95% (p
There is an increase need and demand to update Malaysian Food Composition Database (FCD) which was last updated in 1997. The current FCD program was designed to expand the quantity and improve the quality of the existing database. The present work was aimed to determine the nutrient content of commercial rice products from three rice varieties classified as raw and processed foods, namely Basmati, Siam, and Fragrant rice. A total of six brands from each type of rice were sampled from a local supermarket within Klang Valley. Analyses were carried out for 27 nutrients that include proximate (Energy, Water, Protein, Fat, Carbohydrate, Total Dietary Fibre, and Ash), minerals (Magnesium, Calcium, Sodium, Iron, Zinc, and Copper), water soluble vitamins (C, B1, B2, B3, B6 and B9), fat soluble vitamins (A and E), total sugar, fatty acids (total saturated fat, total monounsaturated fat and total polyunsaturated), trans fatty acids, and cholesterol. The three rice varieties were found to contain comparable nutrient levels except for vitamin C, B1, A, E and total sugar which were not detected in all samples. The fatty acid (total saturated, total monounsaturated, and total polyunsaturated) as well as trans- fatty acid were detected at very low levels. Cholesterol was not detected in all samples. These findings can be utilised in raising public awareness and assistance to better estimate nutrient contents and intake depending on the varieties of rice.
Shiga toxin-producing E. coli (STEC) is an important foodborne pathogen causing diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome in humans. STEC is an implicated in the vast majority of outbreaks, widely via consumption of STEC contaminated beef, as important vehicle of transmission of this organism to human. The E. coli O157:H7 serotype is traditionally identified by serological identification of the somatic antigen (O157) and structural flagella (H7). In this study, the bacteria were identified as STEC serotype O157:H7 with three primer pairs that amplified fragments of secD, rfbE and fliC genes in PCR assays. These primer pairs specifically amplified different sizes of target genes: a 244bp region of the E. coli diagnostic marker gene (secD); a 317bp region of the O157 lipopolysacharide (LPS) gene (rfbE); and a 381bp region of the H7 flagellin gene (fliC). The singleplex, duplex and triplex PCR assay developed in this study have a sensitivity limit at 2.8 x 103, 2.8 x 105 and 2.8 x 107 CFU/ml of E. coli O157:H7, respectively. Sensitivity to detect trace amount of E. coli O157:H7 DNA was reduced as the number of primer used was increased for competing to the same DNA template.
Foodborne diseases are mainly caused by bacterial contamination which can lead to severe diarrhea. This study aimed to detect the presence of Shiga toxin-Producing Escherichia coli O157, Escherichia coli non-O157 and virulence gene in raw vegetables. The samples were purchased from wet market and hypermarket in Selangor. The detections were carried out by using the combination methods of Most Probable Number-Polymerase Chain Reaction (MPNPCR). A total of 37(18.5%) samples were found to be contaminated by STEC. Out of these 37 isolates, four (10.8%) of the isolates were E. coli O157 while 33(89.2%) were E. coli nonO157. However, there was no E. coli O157:H7 detected in all the samples. The occurrence of Shiga toxin-Producing E. coli in edible raw vegetables samples suggests the importance of this pathogen in vegetables. Therefore, more studies are required to remove this pathogen from vegetables.
The optimisation of fresh fruit bunch (FFB) sterilisation process was studied using different degree of FFB ripeness (i.e. under-ripe, ripe, overripe) and loose fruits. This study was carried out with the application of Response Surface Methodology (RSM), based on the interrelation between process temperature (X1; 100 to 120oC) and time (X2; 20 to 80 min) used for FFB sterilisation process on Free Fatty Acid, FFA (Y1,underripe FFB; Y2,ripe FFB; Y3,Overripe FFB; and Y4,loose fruits). Thirteen experimental runs were conducted per degree of ripeness using laboratory scale steriliser with varying sterilisation temperature and time, as generated by Central Composite Rotatable Design (CCRD). Raw experimental data trend showed substantial FFA increment with the increment of FFB maturity. Four polynomial models were found appropriate to predict the responses within experimental regions. Analysis regarding factor influences on each response was performed using Analysis of Variance (ANOVA) and graphical analysis. For under-ripe and ripe FFB, the temperature exerted higher and significant (p
Chhana jalebi is a popular product in middle and northern parts of India and is prepared by frying of batter made from chhana, maida and water and finally soaking in sugar syrup. This chhana based fried sweet product is being prepared and sold by halwais in Indian sweet market. It has a coiled structure with syrupy interiors and chewy body. It has close resemblance to maida jalebi and khoa jalebi, but has firmer coils. The manufacturing procedure varies widely from manufacturer to manufacturer. There was no proper (standard) manufacturing method available for the preparation of chhana jalebi. Hence, a study was conducted to standardize a method for its manufacture consequently it will be helpful to produce the jalebi on a commercial scale. The chhana jalebi was standardized by various process parameters such as fat level in milk 3%, ratio of maida - chhana combination 1:1, water level in batter 45%, frying time and temperature 160-170°C, sugar syrup concentration 68°Brix and soaking time 2 min. Standardized product was analyzed by various physical, chemical, microbial, sensory and textural characteristics. The product had a light brown coloured coiled appearance, crispy body and texture. The nutritional composition percentage of chhana jalebi was protein 5.71±0.20, carbohydrate 67.11±0.19, fat 12.53±0.17 and moisture 20.23±0.25. The shelf life of the jalebi was found to be 5 days at 28°C. This was enhanced to 18 days by using potassium sorbate as preservative at the permitted levels. The optimized process and enhanced shelf life will pave way for commercialization and mechanization of chhana jalebi by food industry.
This study investigated the antioxidant activity and functional properties of fractionated cobia skin gelatin hydrolysate (CSGH) at different molecular weights (10, 5 and 3 kDa). Antioxidant activities studied included reducing power, ferrous ion chelation, DPPH (1, 1- diphenyl-2- picrylhydrazyl) radical scavenging, and superoxide anion scavenging. Functional properties studied included emulsifying and foaming properties as well as fat and water binding capacity. Results showed significant differences (p
Clinacanthus nutans (Burm. F.) Lindau or locally known in Sabah, Malaysia as ‘Sabah Snake Grass’ has been ethnobotanically used to treat various diseases in Asian countries. This study was conducted to determine the total phenolics content (TPC), flavonoids content (TFC) and antioxidant activity of herbal teas developed from C. nutans leaves with different drying techniques (microwave-oven dried and freeze dried) and infusion time (1, 2, 5, 10, 15 and 20 min). Ferric reducing/antioxidant power (FRAP) assay, 2,2’-azino-bis(3-ethylbenzothiazoline- 6-sulphonic acid (ABTS) and 2, 2-diphenyl-1-pycryl-hydrazyl (DPPH) free radical scavenging assays were used to investigate the antioxidant capacity. The highest TPC of herbal tea was observed in 20 min infusion of unfermented microwave-oven dried leaves (177.80 ± 19.10 mg TAE/L), while the highest TFC was observed in 10 min infusion of fermented microwave-oven dried leaves (22.13 ± 1.53 mg CE/L). Short infusion times from 5 min to 15 min were able to extract high amount of phenolics compounds. Unfermented tea contained higher TPC content (P < 0.05) as compared to fermented tea, while, TFC showed no significant difference between both types. Freeze dried infusion shows no significant difference (P > 0.05) as compared to microwave-oven dried for TPC, TFC and antioxidant capacity. Moderate and low correlation was observed between TPC and FRAP values (r = 0.507) and between TFC and ABTS values (r = 0.256). Preparation of C. nutans herbal tea as potential natural antioxidant source can be used as a basic reference for future research on the dietary intake of these herbal teas.
This study was focused on the effect of incorporation of oyster mushroom, Pleurotus sajor- caju (PSC) powder to partially replace chicken meat in frankfurters on nutritional composition, β-glucan content and textural properties. The frankfurters were formulated with either 0 (control), 2, 4 or 6% of PSC powder. The results show control chicken frankfurter had the highest fat content (11.60%) while 6% PSC frankfurter had the lowest value (10.74%). In other nutrient, ash, moisture and carbohydrate content in all samples ranged from 1.55 to 1.92%, 59.36 to 61.98% and 8.84 to 13.09%, respectively. Apparently, total dietary fiber of chicken frankfurter was increased in line with the levels of PSC powder (0.08 - 6.20%). All samples recorded β-glucan in the range from 0.16 to 1.43%, except for control sample. The texture profile showed that both adhesiveness and cohesiveness attributes were not significantly different among all mushroom-based frankfurters. However, frankfurter added with 6% mushroom was more cohesive and springier than the control formulation. In summary, partial replacement of chicken meat with PSC powder resulted in enhancement of dietary fibres up to 6.20% and β-glucan up to 14.30% significantly, lowering fat content but unchanged adhesiveness and cohesiveness attributes. Therefore, PSC powder can be considered to be used as an alternative functional ingredient to improve nutritional values of processed food products.
The aims of this study are to report on the extraction and characterization of Asian swamp eel (Monopterus albus) skin gelatin. The characterization conducted were includes chemical composition, pH, gel strength, viscosity, thermal property, color and structure determination of extracted eel skin gelatin. Eel skin contains 70.28% moisture, 11.07% protein, 4.21% fat, and 5.01% ash. The chemical composition of eel skin gelatin (yield of 12.75%) was 18.8% moisture, 67.64% protein, 0.34% fat and 1.08% ash, with a pH of 4.62 and gel strength of 215.96 g (± 9.62 g). Although viscosity (2.8 cPa/min) profile of eel skin gelatin showed lower than that of bovine gelatin, the higher melting temperature (35 °C) of eel skin gelatin indicating its higher stability than bovine gelatin with FTIR spectrum similar to that of typical bovine gelatin. Eel skin gelatin has a 71.4 (± 1.14), a +3.2 (± 0.29), and a +7.52 (± 0.29) for L*, a* and b* value respectively, indicate a darker and less yellow colour. These findings show promising potential for the application of eel skin gelatin as an alternative to commercial gelatin.
Tamarind and pineapple fruit pulps and powders were assessed based on their physicochemical properties such as crude protein, crude fibre, fat, ash, moisture content, water activity (Aw), particle shape, particle size distribution, and density. Both of the fruit powders were subjected to a similar spray-drying process with the addition of 10% w/v of maltodextrin. The nutritional value in terms of crude protein (0.33 - 0.60%), moisture content (4.80% - 25.31%), crude fiber (16.92 - 79.92%), and fat (0.40 - 0.63%) for both fruit pulp and powders shows a significant difference at p
This study was carried out to determine recognition threshold and taste preference for three basic tastes (sweetness, saltiness and sourness) based on location (interior and coastal) among the Kadazandusun ethnic in Sabah, Malaysia. One hundred and ninety four (194) volunteers aged 20 to 55 years were selected randomly (stratified) as subject. Three Alternative Forced- Choice (3AFC) and hedonic test were used to determine the taste threshold and preference. The interior group had lower taste threshold for all tastes; sweet (10.97 g/L ± 3.69), salty (1.14 g/L ± 0.38), sour (0.0095 g/L ± 0.011) compared to the coastal group; sweet (11.56 g/L ± 3.71), salty (1.23 g/L ± 0.39), sour (0.0012 g/L ± 0.0034). For intensity and hedonic rating, the patterns of response varied based on location for sweet and sour taste. No significant different (p>0.05) was observed for salty taste. However, both groups preferred the base stimulus which concentration similar to the commercially available products tested. There is a correlation between taste threshold and optimum concentration. Individuals with preferred high taste intensity tend to have higher taste threshold. Location and culture can influenced individual taste preference. However, exposure and experience to taste sensation was the major factor on individual’s taste preference.
This study reported the extraction optimization and characterization of cobia (Rachycentron canadum) skin gelatin. Optimization study was carried out to determine the effect of CH3COOH concentration, skin to water ratio, extraction temperature and extraction time on gelatin yield (GY) and gel strength (GS) using Response Surface Methodology (RSM). The optimum conditions were 0.15mol/L for CH3COOH concentration, 82.4oC of extraction temperature, 6 h of extraction time and 1:6 of skin to water ratio, which produced cobia gelatin with GY of 20.10% and GS of 205.6 g. Characteristics of cobia skin gelatin (CG) were then compared to that of commercial bovine gelatin (BG). It was found that the most dominant amino acid in CG was glycine, proline and alanine. There was no difference in foaming and emulsifying properties of CG and BG at 1% concentration, but at 2% and 3% concentration, BG performed better. CG was found to have higher fat binding capacity but lower water holding capacity than BG. Least gelling concentration for CG was recorded at 2% while for BG at 1%. CG and BG had a pI at pH 6.05 and 4.82, respectively. This study shows that cobia skin gelatin has potential as halal alternative to bovine gelatin in food industry.
Optimization of microwave assisted extraction of dragon fruit peel pectin was conducted using respond surface methodology. Effect of extraction conditions, i.e. pH value (X1), extraction time (X2) and solid-liquid ratio (X3) on the extraction yield was investigated using a central composite experimental design. Optimization of microwave assisted extraction was performed and three-dimensional (3D) response surface plots were derived from the mathematical models. Analysis of variance (ANOVA) was conducted and indicated a significant interaction between extraction conditions (pH value and extraction time) and extraction yield. The optimum conditions of microwave assisted extraction were as follows: X1 = 2.07; X2 = 65 s and X3 = 66.57. The verification test on pectin extraction was performed and revealed a perfect agreement between experimental and predicted values. The maximum predicted yield of pectin extraction was 18.53%. Overall, application of microwave assisted extraction can give rise to high quality dragon fruit peel pectin.
This study examines and compares the influence of pH on the functional, rheological and structural properties of eel skin (Monopterus sp.) and bovine gelatins. Functional properties studied and compared were emulsifying capacity and stability; water holding capacity; fat binding capacity; foaming capacity; and foaming stability. The rheological properties studied include gel strength and dynamic oscillatory measurements. The structural properties of eel skin and bovine gelatin were determined by Fourier transform infrared spectroscopy (FTIR). Results obtained showed that eel skin gelatin treated at pH 8 (compared to pH 5) exhibited the higher emulsifying, fat binding, foaming and viscoelasticity properties. The FTIR spectrum assay showed that eel skin gelatin presented a similar structure to that of bovine gelatin. This study demonstrated that pH levels influence functional, rheological and structural properties of eel skin gelatin and that these properties were enhanced to either equal or surpass those of bovine gelatin. Hence, this study indicates that eel skin gelatin has immense potential for use as an alternative to bovine gelatin.
This study investigates effects from different drying methods (vacuum oven dried vs. freeze dried) on the rheological, functional and structural properties of chicken skin gelatin compared to bovine gelatin. Vacuum oven dried chicken skin samples showed a higher gelatin yield (12.86%) than freeze-dried samples (9.25%). The latter showed a higher melting temperature (32.64oC) and superior foaming capacity (176%) as well as foaming stability (166.67%). Vacuum oven dried samples demonstrated greater fat binding capacity (5.5 ml/g) and emulsion stability (55.79%). There were no significant differences (p >0.05) in emulsion and water holding capacity for three gelatins. Bovine gelatin did hold the lowest of all functional properties studied. A Fourier Transform Infrared (FTIR) spectrum analysis of chicken skin gelatin under both drying methods presented structures similar to those of bovine gelatin. Collectively, this findings indicated no significant differences (p >0.05) in rheological, functional and structural properties for chicken skin gelatins prepared by either drying method. Hence, to save costs and maintain gelatin quality, vacuum oven drying offers potential as an alternative means of production.