Optimization of enzymatic hydrolysis condition of Angelwing Clam (Pholas orientalis) meat using Alcalase® to obtain maximum degree of hydrolysis

Optimization of enzymatic hydrolysis conditions of angelwing clam (Pholas orientalis) meat (ACM) catalysed by Alcalase® to obtain the maximum degree of hydrolysis (DH) was carried out using Response Surface Methodology (RSM). A three level face-centered central composite design (CCD) was employed. Four independent variables of enzymatic hydrolysis conditions were applied, which were pH (6.5–8.5), temperature (55–65°C), hydrolysis time (30–120 min), and Alcalase® to substrate concentration (0.5–2.5%). The optimum condition was obtained at pH of 7.34, the temperature of 64.1°C, hydrolysis time of 104.2 min and Alcalase® to substrate concentration of 1.65%. It was found that the quadratic model can be used to describe the relationship between enzymatic hydrolysis conditions of ACM with DH. Verification of the model showed that at optimum condition, the predicted DH value (99.47%) was close to the experimental DH value (98.75%) (p>0.05). Lyophilized ACM hydrolysate produced under optimum condition composed of 5.76±0.17% moisture, 65.09±1.09% protein, 1.65±0.06% fat, 19.95±0.49 ash%, and 7.56±0.80% carbohydrate. This study showed that the degree of hydrolysis of the enzymatic hydrolysis of ACM catalysed by Alcalase® could be predicted using RSM

In silico analysis of edible bird’s nest proteins as potential precursors for bioactive peptides

The present study aimed to perform an in silico evaluation of edible bird’s nest protein as potential precursors of bioactive peptides, as well as to determine whether such peptides can be released by selected proteolytic enzymes. Six edible bird’s nest (EBN) protein sequences from a previous study were chosen as potential precursors to produce bioactive peptides via in silico method using the BIOPEP database. AMCase protein sequences gave the highest number of bioactivities (16 to 18) and nucleobindin-2 protein gave the lowest number of bioactivities (9) among the other protein sequences. It was found that the most potential bioactive peptides from EBN proteins are angiotensin-converting enzyme (ACE) inhibitors and dipeptidyl peptidase-IV (DPP-IV) inhibitors. Furthermore, in silico proteolysis using six selected enzymes was employed to release both dominant bioactivities in EBN proteins, which were ACE and DPP-IV inhibitors. This study shows that a combination of enzymes, chymotrypsin, and papain, produced the highest number of activities for both ACE and DPP-IV inhibitor peptides with the frequency of occurrence of bioactive peptides of 0.0968 and 0.1104, respectively. The toxic prediction tool, ToxinPred, found that all EBN peptides derived by in silico analysis were non-toxic. The current study proposed that EBN can serve as a potential source of bioactive peptides

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

Properties of an Emulsion Gel with Gracilaria fisheri Agar, Whey Protein Isolate and Black Seed Oil

Gracilaria fisheri agar has beneficial potential for human health; however, its application in food products needs to be incorporated into an emulsion gel due to its low gel strength. A response surface methodology with a central composite design was utilized to prepare emulsion gels containing 4–6% Gracilaria fisheri Agar (AGF), 4–8% Whey Protein Isolate (WPI) and 10–20% Black Seed Oil (BSO). The optimum levels of AGF, WPI, and BSO were determined to be 6%, 4% and 10% respectively to give the preferred gel strength of 966.24 g, water holding capacity of 96.12%, and DPPH antioxidant activity of 59.16%

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

Optimization of enzymatic hydrolysis conditions of seaweed (Gracilaria fisheri) protein by using Alcalase® to obtain maximum angiotensin-I-converting enzyme (ACE) inhibitory activity

This study aimed to optimize the enzymatic hydrolysis conditions of Gracilaria fisheri protein by using Alcalase® to obtain maximum angiotensin-I-converting enzyme (ACE) inhibitory activity. Firstly, the seaweed protein was extracted using cellulase, sonication, and ammonium sulphate treatment, before dialysis and lyophilization. The yield of lyophilized seaweed protein extract was 8.75% with a protein content of 66.4%. An optimization study for protein hydrolysis condition was performed by employing a three-level face-centered central composite design (CCD) using Design-Expert software. Four parameters used were pH (6.5 – 8.5), temperature (50 – 60°C), hydrolysis time (60 – 180 min), and Alcalase® to substrate ratio (E/S) (1.25 – 2.50%). Thirty runs of protein hydrolysis conditions with 6 center points were employed. The supernatant of the resulting protein hydrolysates was then lyophilized and analyzed for ACE inhibitory activity. This study found that the quadratic model could be used to explain the relationship between hydrolysis conditions of G. fisheri protein and ACE inhibitory activity. The optimum condition to obtain maximum ACE inhibitory activity was at pH of 7.5, the temperature of 54.6°C, hydrolysis time of 175 min, and E/S of 1.47%. The half-maximal inhibitory concentration (IC50) of the seaweed protein hydrolysate at optimum condition was 2.97 ± 0.37 mg/mL

Effect of heat pretreatments on chemical and antioxidant properties of Melon Manis Terengganu (Cucumis melo var. Inodorus cv. Manis Terengganu 1) seed oil

The main objective of this study was to determine effect of different heat pretreatments on chemical and antioxidant properties of Melon Manis Terengganu (MMT) seed oil. The seeds were treated with four different heat pretreatment which were untreated (control), roasting, steaming and microwaving. Then the MMT seed oil was extracted from each treated seed using conventional extraction method. The chemical tests determined on the MMT seed oil were free fatty acid (FFA), iodine value (IV), saponification value and fatty acid composition. The antioxidant properties for MMT seed oil evaluated was total phenolic content (TPC), 1,1- diphenyl-2-picrylhdrazyl (DPPH) scavenging capacity and Ferric reducing antioxidant power (FRAP). It was found that different heat pretreatments of MMT seed significantly (p<0.05) affected the oil yield (11.10–15.40%.), free fatty acid value (3.55–5.04%), DPPH radical scavenging activity (43.06–56.08%), total phenolic content (0.088–0.142 mg GAE/g) and FRAP activity (0.0723–0.110 mmole/100 mL). However, the seed heat pretreatment did not affect the fatty acid composition significantly (p<0.05). As for iodine value, it was different between untreated seed (107.89 g I2/100g) and steamed seed (104.41 g I2/100g) only (p<0.05)

Purification and characterisation of angiotensin I converting enzyme (ACE) inhibitory peptide from blood cockle (Anadara granosa) meat hydrolysate

Blood cockle (Anadara granosa) is the most abundant and available bivalves in Malaysia. Blood cockles meat has high protein content and has potential to generate bioactive peptides. To date, no study has been reported on purification and identification of angiotensin I converting enzyme (ACE) inhibitory peptides from blood cockle meat. Thus, the objectives of this study were to purify and characterize ACE inhibitory peptide from blood cockle meat hydrolysate. ACE inhibitory peptides from blood cockle meat hydrolysate (CMH) were prepared by enzymatic protein hydrolysis using Protamex®. Crude CMH was characterized for its stability against gastrointestinal proteases, at varying pH (2–11) and temperature (4–90°C). Next, crude CMH was purified by ultrafiltration, ion exchange chromatography and reverse-phase chromatography and its amino acid sequence was identified. It was found that crude CMH was highly stable at low pH and temperature, and was resistant to gastrointestinal proteases (pepsin and trypsin). A three-step purification increased the inhibitory activity of CMH, reducing its IC50 from 0.35 mg/ml to 0.0094 mg/ml. The amino acid sequence of the purified peptide was determined as VNDLLSGSFKHFLY, with a molecular weight of 1621.88 Da. This study suggested the potential of ACE inhibitory peptide derived from cockle meat as a nutraceutical ingredient in functional food

Effect of Yellowstripe scad (Selaroides leptolepis) protein hydrolysate in the reduction of oil uptake in deep-fried squid

Although the fried products are delicious with a tenderizing effect on the crust due to the presence of fat, over-consumption of fried products causes health problems, especially coronary diseases. The tendency of proteins in film formation and thermal gelation to reduce the absorption of oil in fried products is emphasized. The purpose of this study was to determine the reduction of oil in deep-fried squid by the incorporation of protein hydrolysate and to discuss its effect. Yellowstripe scad protein hydrolysate was produced using Alcalase® enzyme. Fat content was determined using the Soxhlet method, subsequently substituted into a formulation for oil uptake calculation. The viscosity of batter was determined using a rheometer. The viscosity of the batter and batter pick-up was found to be directly proportional, showing a significantly reduced pattern from 0 to 20%. Incorporating 10% of fish protein hydrolysate successfully decreased oil absorption by 17.35±0.73% with a good water retention rate of 38.46%. The addition of the Yellowstripe scad fish protein hydrolysate modified the size and shape of the pore. Sensory acceptance portrayed no significant difference among the three samples (0%, 5% and 10% of incorporation), indicating that panellists were able to accept samples incorporated with fish protein hydrolysate. The findings of this study showed that Yellowstripe scad protein hydrolysate can minimize the uptake of oil in fried seafood products and thus could increase the economic value of the Yellowstripe scad fish

Effect of sodium acetate, chilli and turmeric on the shelf life of refrigerated tilapia fillet

The aim of this study was to determine the effects of turmeric powder, chilli powder and sodium acetate on the shelf life of refrigerated tilapia fillets at 5ºC. Six treatments were applied to the tilapia fillets which were salt (S), salt and turmeric (ST), salt and chilli (SC), salt, turmeric and sodium acetate (STNaA) and salt, chilli and sodium acetate (SCNaA) and control. The samples were analyzed in 15 days period for microbiological, chemical and physical analyses. It was found that there were significant differences (p<0.05) in all microbiological analysis of fish treated with STNaA and SCNaA compared to other treatments. Microbiologically, the shelf life of fillets treated with STNaA and SCNaA was 12 days, fillets treated with ST, SC and S were 6 days, and only 3 days for control fillet. In terms of TVB-N and TMA values, ST fillets were still acceptable up to 12 to 15 days of refrigerated storage. As for TBA values, they were in acceptable range for all treatments throughout 15 days storage. The texture quality in decreasing order was given by fillets with SCNaA, SC, STNaA, ST, S and control treatment. In conclusion, the best treatment to extend the shelf life of refrigerated Tilapia fillet was given by STNaA, followed by SCNaA and ST