Chemical composition and potential adulterants in coconut milk sold in Kuala Lumpur

The purpose of this study was to determine the chemical composition of six fresh coconut milk samples sold in Kuala Lumpur and to compare the results of chemical composition with pure coconut milk as reference using Malaysia Food Composition, USDA Fresh Coconut Milk Composition and USDA Canned Coconut Milk Composition. The possible source of adulterants that might present in coconut milk was also studied. Two fresh coconut milk samples from Pasar Imbi and Giant Cheras was anticipated to be adulterated with water and a source of carbohydrate in order to thicken the coconut milk. The protein content of fresh coconut milk sample from Pasar Imbi and Giant Cheras was 79.05% and 80.95%, respectively, lower compared to the reference, while the fat content was 53.38% and 60.96% lower compared to the value of the reference. However, the carbohydrate was 16.37% and 5.75%, while the moisture content was 12.84% and 25.77% higher compared to the value of the reference. From these two potentially adulterated coconut milk samples, only coconut milk from Pasar Imbi shown carbohydrate (corn flour) and water peaks of Fourier transform infrared (FTIR) spectra. The spectra of fresh coconut milk adulterated with different concentration of corn flour were scanned and interpreted. Partial Least Square (PLS) regression was used to quantitatively determine the concentration of corn flour in the coconut milk. The linear equation of the validation obtained was y = 0.9161x + 0.3334 with R2= 0.9982 and RMSEC= 0.688. This can be suggested that FTIR could be a potential tool in determining the coconut milk adulteration with corn flour for future study

Effect of different drying methods on the degradation of selected flavonoids in Centella asiatica

The effect of different drying methods on the degradation of flavonoids in Centella asiatica was evaluated. C. asiatica leaf, root and petiole were dried using air-oven, vacuum oven and freeze drier. Flavonoid was determined utilizing reverse-phase high performance liquid chromatography (RP-HPLC). Results of the study revealed the presence of high concentration of flavonoids in C. asiatica leaf, root and petiole, which include, naringin (4688.8 ± 69 μg/100 g, 3561.3 ± 205 μg/ 100 g, and 978.3 ± 96 μg/ 100 g), rutin (905.6 ± 123 μg/ 100 g, 756.07 ± 95 μg/ 100 g, and 557.25 ± 58 μg/ 100 g), quercetin (3501.1 ± 107 μg/ 100 g, 1086.31 ± 90 μg/ 100 g, and 947.63 ± 83 μg/ 100 g) and catechin (915.87 ± 6.01 μg/ 100 g, 400.6 ± 67 μg/ 100 g, and 250.56 ± 18 μg/ 100g). Luteolin, kaempferol and apigenin on the other hand, were inconsistently present in some parts of C. asiatica. Air-oven treatment resulted in the highest total flavonoids degradation followed by vacuum oven and freeze dried with percent degradation of 97%, 87.6% and 73%, respectively. Catechin and rutin were found to be the most stable flavonoids with percent degradation up to 35%, 66% and 76% for freeze dried, vacuum oven and air oven, respectively

Effect of hydrolysis time on antioxidant and antimicrobial properties of Jack Bean (Canavalia ensiformis) protein hydrolysate

Jack Bean or Kacang Koro (Canavalia ensiformis) is one of the under-exploited tropical dry beans. This study was aimed to determine the effect of hydrolysis time on physicochemical properties, antioxidative and antimicrobial activity of Jack Bean protein hydrolysate (JBPH). The physicochemical properties of JBPH were evaluated based on protein content, WHC, OHC, degree of hydrolysis, foam stability and foaming capacity. The antioxidative activity of JBPH was measured using DPPH, hydroxyl radical scavenging, superoxide radical scavenging and FRAP. Well diffusion method was used to study antimicrobial activity of JBPH. The highest protein content (33.16±0.03%) obtained in JBPH that hydrolysed for 150 min. The degree of hydrolysis was showed for JBPH highest at 120 min (51.79±0.28%). The size of the microstructure of JBPH analysed using SEM were decrease with hydrolysis time. FTIR analysis confirmed that JBPH comprised of three major components (Region I, II and III). Water holding capacity of JBPH was the highest for the sample hydrolysed for 60 min (63.87±0.72%) while oil holding capacity depicts the highest by it at 180 min (57.17±1.19%). Foaming capacity and foam stability decreased with hydrolysis time. JBPH produced at 120 min hydrolysis time showed the highest inhibition toward DPPH (42.44%) and hydroxyl radicals (20.01%). FRAP and superoxide radical scavenging, JBPH at 90 min showed the highest inhibition (91.15±0.05 µM and 64.33%). JBPH also showed antimicrobial properties by inhibits the growth of P. aeruginosa. The best hydrolysis time to produce JBPH with the highest physicochemical properties was found at 120 min

Antioxidative activity and total phenolic compounds of leaf, root and petiole of four accessions of Centella asiatica (L.) Urban

Antioxidative activity and total phenolic compounds of root, leaf and petiole of four accessions of Centella asiatica (L.) Urban, namely CA 01, CA 05, CA 08 and CA 11, were evaluated. Antioxidative activity of the extracts was measured using the ferric thiocyanate (FTC) method and thiobarbituric acid (TBA) test. The antioxidative activities were then compared with that of α-tocopherol (natural antioxidant) and butylated hydroxytoulene or BHT (synthetic antioxidant). The results showed that CA 01 and CA 05 had the highest antioxidative activities among the accessions tested. Results also showed that both leaf and root of C. asiatica had high antioxidative activity, which was as good as that of α-tocopherol. The total phenolic content, determined according to the Folin–Ciocalteu method, varied from 3.23 to 11.7 g/100 g dry sample, and showed strong association (r2=0.90) with antioxidative activity. The results suggest that phenolic compounds are the major contributors to the antioxidative activities of C. asiatica

The Influence of Seaweed Composite Flour on the Physicochemical Properties of Muffin

Seaweed has a great potential to be used as an important ingredient in food processing, as it contains a significant content of soluble polysaccharides and has a potential function as a dietary fiber. In this study, seaweed powder (Kappaphycus alvarezii) was incorporated (2–10%) with wheat flour for the production of muffins. The effect of seaweed composite flour on the quality of muffins was investigated using various techniques, such as texture profile and proximate analyses, as well as sensory evaluation. Modification of the muffin formulation to include seaweed powder improved the composition of ash, crude fiber, and moisture content, while the protein and carbohydrate levels decreased, compared to the control sample. An increase in the seaweed component reduced the muffin height, volume, and specific volume. According to the experimental texture profile analysis data, the seaweed affected the textural characteristics of the muffins, increasing the hardness and decreasing the springiness. Sensory evaluation revealed that seaweed powder could be used in the muffin formulation up to 6%, without significantly impacting the color, aroma, and taste attributes relative to the control sample. For overall acceptability, however, the panelists preferred muffins without seaweed powder

Optimisation of enzymatic protein hydrolysis of mud crab (Scylla sp.) to obtain maximum angiotensin-converting enzyme inhibitory (ACEI) activity using response surface methodology

Optimisation is commonly employed to find the conditions that produce the best possible response, thus minimizing the cost and time of a particular process. Response Surface Methodology (RSM) is a widely used tool in optimisation. This study reported the optimisation of enzymatic hydrolysis of mud crab meat using RSM by employing a face-centered Central Composite Design (CCD) to obtain maximum angiotensin-converting enzyme inhibitory (ACEI) activity. Screening of commercial food grade proteinases was carried out using Alcalase®, Protamex®, Neutrase® and papain shows that Protamex® gave the highest ACEI activity. The enzymatic hydrolysis conditions used in the optimisation were temperature (45-65ºC), pH (pH 5.5-7.5), hydrolysis time (1-4 hours) and Protamex® enzyme to substrate (E/S) ratio (1-3%). It was found that quadratic model was able to explain the relationship between the hydrolysis conditions and ACEI activity. The optimum conditions were obtained at 65ºC, pH 5.6, 1% E/S ratio and 4 hours of hydrolysis time. The experimental ACEI activity (88.93±1.02%) was not significantly difference (p>0.05) with the predicted ACEI activity (91.10%). It was found that the IC50 of the mud crab hydrolysate prepared at optimum condition was 1.96±0.13 mg/mL. This study shows that RSM can be used to explain the relationship between enzymatic hydrolysis conditions of mud crab meat and its ACEI activity

Effect of pre-treatment on physical properties, ascorbic acid and -carotene content of frozen sweet corn kernels hibrimas (Zea mays var Saccharata bailey) variety

The main objective of this study is to investigate the best pre-treatment based on physical properties, ascorbic acid and β-carotene content of frozen sweet corn kernels of the Hibrimas variety. Five types of pre-treatments being studied: water blanching, steam blanching, 0.5% citric acid blanching, 2.0% sodium chloride blanching and 1.0% sodium metabisulfite blanching. It was discovered that sodium metabisulfite blanching can improve texture of frozen corn kernels while citric acid blanching play vital role in colour and total soluble solids retention. pH value is more stable after subjected to steam pretreatment. Chemical pre-treatments were outweighing physical pre-treatments in ascorbic acid retention. There were no significant effects showed by pre-treatments on storage weight loss and β-carotene content. Citric acid pre-treatment was suggested to be the best pre-treatment due to its high colour and total soluble content

Optimisation of enzymatic protein hydrolysis of mud crab (Scylla sp.) to obtain maximum antioxidant activity using response surface methodology

This study reported optimisation of enzymatic hydrolysis of mud crab meat using Protamex® to obtain maximum antioxidant activity using Response Surface Methodology (RSM). Prior to optimisation, screening of commercial food grade proteinases was carried out using Alcalase®, Protamex®, Neutrase® and papain. Protamex® was observed to give the highest DPPH scavenging activity. The enzymatic hydrolysis conditions used in the optimisation study were temperature (45-65ºC), pH (5.5-7.5), hydrolysis time (1-4 hours) and enzyme to substrate (E/S) ratio (1-3% Protamex®). A face-centered Central Composite Design (CCD) was employed. It was found that the relationship between hydrolysis conditions and DPPH scavenging activity could be explained by a quadratic model. Optimum condition was found to be at 54ºC, pH 5.5, 1% Protamex® and 1 hour of hydrolysis time. Validation experiment shows that the experimental DPPH scavenging activity (82.39 ± 0.16%) was close to the predicted value (82.64%). The hydrolysate prepared at optimum condition contained 5.52% moisture, 74.81% crude protein, 13.13% ash, 6.26% carbohydrate and 0.28% crude fat with IC50 for DPPH scavenging activity of 3.48 ± 0.05 mg/mL. This study shows that RSM can be used to explain the relationship between enzymatic hydrolysis conditions of mud crab meat and its antioxidant activity

Physicochemical properties of powdered protein hydrolysate from yellowstripe scad (Selaroides leptolepis) fish

Yellowstripe scad fish (YSF) or Selaroides leptolepis belongs to the small pelagic group that is abundantly found in South China Sea and is categorised as low value fishes. This study is designed to explore the physicochemical properties of YSF protein hydrolysate extracted using sodium phosphate buffer followed by 0.5%-2.0% of Alcalase at a series of hydrolysis time (1 hr and 2 hr). The properties of freeze and spray dried protein hydrolysate were evaluated for yield, degree of hydrolysis, protein content, microstructure and water holding capacity. Results showed that prolonged hydrolysis time exhibited increasing yield (0.6%-1.6% for spray drying and 12-16% for freeze drying) and high degree of hydrolysis (80-95%). Protein content recovered from hydrolysis process is within 20-29%. Microstructure of freeze dried YSF protein hydrolysate had 'collapsed-building' structure (irregular shapes with edges) while spray dried had small and spherical structure. Freeze dried protein hydrolysates were significantly (p < 0.05) higher than spray dried hydrolysates in water holding capacity

Assessment of dough rheological characteristics and soft bread roll quality of wheat flour incorporated with seaweed powder

Purpose – This study aims to investigate the effects of incorporating seaweed composite flour on soft roll dough rheological characteristics and quality. Design/methodology/approach – In this study, wheat flour was substituted with seaweed powder obtained from red seaweed (Kappaphycus alvarezii) at varying proportions (100:0; 99:1; 98:2; 97:3; 96:4; 95:5, 94:6, 93:7 and 92:8) and applied in soft roll production. The effects of seaweed composite flour were evaluated in terms of rheological characteristics, proximate composition and physical properties. The sensory characteristics of the soft rolls was evaluated by 40 untrained panellists by using a hedonic scale. Findings – Farinograph analysis of the soft roll doughs showed that the incorporation of seaweed powder promoted an increase in water absorption, development time and mixing tolerance index, whereas it decreased stability time. Analysis of the proximate composition of the soft rolls showed that protein and carbohydrate contents decreased, but moisture, ash and crude fibre contents substantially increased. Dietary fibre increased with the increase in the proportion of seaweed powder added. The specific volume, bulk density and firmness of the soft rolls ranged from 3.01 to 5.48 cm3 /g, 0.18 to 0.33 g/cm3 and 1.86 to 20.63 N, respectively. Sensory evaluation results showed that the mean score of sensory attributes decreased as the proportion of seaweed powder added was increased in the formulations. With regard to the overall acceptability, the panellists preferred the soft rolls with the least amount of seaweed powder added. The results of hedonic tests revealed that the panellists’ acceptance decreased as higher amounts seaweed powder were added in the formulations. Originality/value – This study showed that the seaweed powder of K. alvarezii can be utilised as an ingredient to improve the nutrient composition of baked products