Fractionation and characterisation of sialylated-mucin glycoprotein from edible birds' nest hydrolysates through anion exchange chromatography

Edible bird's nest (EBN) is made up of sialylated-mucin glycoprotein with various health benefits due to its high antioxidative activity. However, as a macromolecule with distinct charged sialic acid and amino acids, fractions with different charges would have varied physicochemical properties and antioxidant activity, which have not been studied. Therefore, this study aimed to fractionate and purify the enzymatic hydrolysed of cleaned EBN (EBNhc) and EBN by-product (EBNhbyp) through anion exchange chromatography (AEC), and determine their molecular weights, physicochemical properties, and antioxidative activities. Overall, 26 fractionates were collected from enzymatic hydrolysate by AEC, which were classified into 5 fractions. It was found that the positively charged fraction of EBNhc (CF 1) and EBNhbyp (DF 1) showed the significantly highest (p < 0.05) soluble protein contents (22.86 and 18.40 mg/g), total peptide contents (511.13 and 800.47 mg/g) and ferric reducing antioxidant power (17.44 and 6.96 mg/g) among the fractionates. In conclusion, a positively charged fraction (CF 1 and DF 1) showed more desired physicochemical properties and antioxidative activities. This research suggests the potential of AEC fractionation as a technology to purify EBN and produce positively charged EBN fractionates with antioxidative potential that could be applied as food components to provide health benefits.

The Nutritional and Functional Properties of Protein Isolates from Defatted Chia Flour Using Different Extraction pH

This study aims to determine the effects of various alkaline pHs on the nutritional and functional properties of protein isolated from defatted chia flour (DCF). The DCF isolated using alkali extraction method at pH 8.5, 10.0, and 12.0 were coded as CPI-8.5, CPI-10.0, and CPI-12.0, respectively. The highest extraction yield and protein recovery yield was demonstrated by CPI-12.0 (19.10 and 59.63%, respectively), with a total protein content of 74.53%, and glutelin showed the highest portion (79.95%). The CPI-12.0 also demonstrated the most elevated essential (36.87%), hydrophobic (33.81%), and aromatic (15.54%) amino acid content among other samples. The DCF exhibited the highest water (23.90 gg-1) and oil (8.23 gg-1) absorption capacity, whereas the CPI-8.5 showed the highest protein solubility (72.31%) at pH 11. DCF demonstrated the highest emulsifying capacity at pH 11 (82.13%), but the highest stability was shown at pH 5 (82.05%). Furthermore, CPI-12.0 at pH 11 shows the highest foaming capacity (83.16%) and stability (83.10%). Despite that, the CPI-10.0 manifested the highest antioxidant capacity (DPPH: 42.48%; ABTS: 66.23%; FRAP: 0.19), as well as ACE-I (35.67%). Overall, the extraction pH had significant effects in producing chia protein isolates (CPI) with improved nutritional and functional qualities.

Edible Bird’s Nest, a Valuable Glycoprotein Source: Current Research Prospects and Challenges in Malaysia

Edible bird's nest (EBN) is a salivary secretion of swiftlets which consist of protein and carbohydrate rich glycoproteins. This natural ingredient is very valuable, nutritional and medically valuable. The EBN industry have grown rapidly and benefited the Malaysian economy, hence, it is viewed seriously and it is actively supported by the government. This review discusses the progress and development of EBN industry as well as the R&D activities and endeavours especially that which involves deriving peptides with biological activities from EBN and its by-product sources. Many studies have documented the therapeutic properties of EBN such as antiaging, antiviral, antioxidant, and antihypertensive. Studies have also been conducted to produce glycoprotein hydrolysates from EBN through enzymatic hydrolysis, and findings showed that these bioactive peptides increase solubility as well as antioxidant and antihypertensive activities. Enzymatic hydrolysis breaks long protein chains at specific sites and releases amino acids and small peptides with lower molecular weights. The EBN hydrolysates produced can improve bioactivity and overcome insolubility and low absorption of EBN prepared and consumed through traditional means. Further studies need to be carried out to optimise EBN glycoprotein hydrolysates production as well as maximising their bioavailability and efficacy in the human gastrointestinal system. In addition, EBN by-products produced during EBN cleaning process should be fully utilised to recover the high-value glycoproteins, while reducing pollution and wastage. By enhancing R&D activities of EBN, bioactive glycopeptides produced from EBN may become an important functional food ingredient for various uses and innovative value-added products in the future.

Kesan Masa Pendidihan dan Simulasi Pencernaan ke atas Protein dan Hidrolisat Protein yang Dihasilkan daripada Sarang Burung Walit Spesies Aerodramus fuciphagus

Sarang burung walit (SBW) dengan kandungan manfaat kesihatan yang pelbagai dihasilkan daripada burung walit Aerodramus fuciphagus. Sarang tersebut dihasilkan menggunakan air liur burung walit yang mengandungi bahan glikoprotein yang tinggi. Kajian ini dijalankan untuk menghasilkan hidrolisat protein SBW dan seterusnya menentukan kesan masa pendidihan (0 - 180 minit) dan proses pencernaan ke atas sampel SBW dan hidrolisat protein SBW. Proses hidrolisis berenzim telah dijalankan dengan menggunakan enzim alkalase untuk menghasilkan hidrolisat protein SBW. Ujian pencernaan terhadap protein SBW dan hidrolisat yang dihasilkan telah dijalankan menggunakan simulasi sistem pencernaan manusia in vitro. Hasil kajian menunjukkan dengan peningkatan masa pendidihan sehingga 180 minit, kandungan peptida yang terhasil daripada pendidihan SBW mentah dan hidrolisat adalah berbeza secara signifikan (p<0.05) dengan nilai kandungan peptida daripada SBW mentah terdidih didapati lebih tinggi daripada hidrolisat SBW. Seterusnya, hasil daripada pencernaan protein terhadap SBW dan hidrolisat SBW menunjukkan nilai kandungan peptida yang berbeza secara signifikan (p<0.05) dengan darjah hidrolisis protein SBW didapati paling tinggi (96.55%); diikuti dengan hidrolisat SBW 60 minit (88.69%), 120 minit (89.32%) dan 180 minit (89.81%) yang tidak berbeza secara signifikan (p<0.05) antara sampel. Hasil kajian ini menunjukkan SBW didegradasi secara aktif dalam masa 30 minit pendidihan berbanding hidrolisat SBW. Perbezaan tersebut menjelaskan bahawa komponen protein pada hidrolisat SBW telah banyak dicernakan oleh tindak balas hidrolisis berenzim dalam penyediaan hidrolisat tersebut. Proses pencernaan in vitro pula menunjukkan bahawa protein SBW dan hidrolisatnya adalah protein makanan yang boleh dicernakan dengan baik oleh sistem pencernaan manusia.

Review of sialic acid's biochemistry, sources, extraction and functions with special reference to edible bird's nest

Sialic acids are a group of nine-carbon α-keto acids. Sialic acid exists in more than 50 forms, with the natural types discovered as N-acetylneuraminic acid (Neu5Ac), deaminoneuraminic acid (2-keto-3-deoxy-nonulononic acid or Kdn), and N-glycolylneuraminic acid (Neu5Gc). Sialic acid level varies depending on the source, where edible bird's nest (EBN), predominantly Neu5Ac, is among the major sources of sialic acid. Due to its high nutritive value and complexity, sialic acid has been studied extensively through acid, aqueous, and enzymatic extraction. Although detection by chromatographic methods or mass spectrometry is common, the isolation and recovery work remained limited. Sialic acid is well-recognised for its bioactivities, including brain and cognition development, immune-enhancing, anti-hypertensive, anticancer, and skin whitening properties. Therefore, sialic acid can be used as a functional ingredient in the various industries. This paper reviews the current trend in the biochemistry, sources, extraction, and functions of sialic acids with special reference to EBN.

A preliminary study on the effects of E-Z Mixin® and EquiPlus® extenders supplemented with Edible Bird's Nest on the quality of chilled Arabian stallion semen

The aim of this study was to evaluate the effects of adding different concentrations of edible bird’s nest (EBN) which is secreted by swiftlet birds (Aerodramus fuciphagus), into EquiPlus® and E-Z Mixin® extenders on the quality of chilled Arabian stallion semen at various storage times (0, 24 and 48 h). Ten ejaculates were collected from five stallions, and diluted using the two extenders containing 0% (control), 0.12%, 0.24% and 0.24% of EBN + seminal plasma (SP). All the diluted semen samples were then cooled and stored at 5 °C, and examined at 0, 24 and 48 h. Sperm kinetic parameters were assessed using computer assisted sperm analysis (CASA) and viability were assessed using Hoechst33342/PI stain. In both extenders, total motility (TM) and progressive motility (PM) were significantly higher at 0.12% and 0.24% compared to 0.24% + SP at 24 and 48 h. At 0.12%, E-Z mixin® treated semen had significantly higher TM and PM than EquiPlus^® at 24 and 48 h. At 0.12% and 0.24%, average path velocity (VAP), straight-line velocity (VSL) and curvilinear velocity (VCL) were significantly higher in E-Z mixin® treated semen compared to EquiPlus^® at 24 and 48 h. Comparisons between the two extender types at different concentrations of EBN showed no significant difference in lateral head amplitude (ALH), linearity (LIN), straightness (STR), beat cross frequency (BCF) and viability, irrespective of the storage time. The percentage of viable was significantly higher in E-Z mixin® than EquiPlus® at 0 and 48 h in control and 0.12%. Supplementation of the E-Z mixin^® extender with 0.12% and 0.24% EBN concentrations in the absence of SP provided better CASA parameters such as TM, PM, VAP, VSL, and VCL at 24 and 48 h storage time. In conclusion, the results of this study indicated that chilled semen from Arabian stallion that was extended using E-Z mixin® and supplemented with 0.12% and 0.24% EBN concentrations performed better and yielded superior results in sperm kinetic parameters and % viable compared to EquiPlus® at 24 and 48 h storage time.

Swiftlet’s Nest as Potential Prebiotic Compound for the Gut Beneficial Bacteria

Swiftlet’s clean and edible nest has been consumed for centuries as health food. The benefits of the edible bird nest (EBN) are commonly based on historical and observational reports since its discovery, until some were proven scientifically at recent times. The EBN has a potential to be a prebiotic with the bioavailability of glycan within the EBN. In order to test the prebiotic potential, the EBN glycoprotein and EBN extracted glycan went through a simulated human digestion in vitro test which contained at the level of oral, gastric and small intestine. The undigested components were collected and further tested with simulated in vitro human colon model. The findings showed that the improved growth of beneficial bacteria in the presence of EBN substrates have potentials to provide health benefits. The beneficial group of bacteria may improve and strengthened the host immune system and reducing the risk of pathogenic bacterial infection. These health benefits are crucial especially during the severe health situation such as the pandemic of COVID-19. This study had contributed to the functional properties of the EBN, as a prebiotic for the benefits of consumers and EBN industries. The fundamental of this finding in regards to prebiotic activity can be applied to the area of animal production in the application of prebiotics as value added animal feed ingredients.

Enzymatic hydrolysis: Sialylated mucin (SiaMuc) glycoprotein of edible swiftlet's nest (ESN) and its molecular weight distribution as bioactive ESN SiaMuc-glycopeptide hydrolysate

Bioactive edible swiftlet's nest (ESN) sialylated-mucin (SiaMuc) hydrolysate is produced by alcalase hydrolysis. Enzymatic hydrolysis of ESN breakdown high-valued ESN SiaMuc-glycoprotein into bioactive SiaMuc-glycopeptide. This is a breakthrough for the issue of insolubility and low extraction rate in ESN, and even increases the bioavailability of ESN nutritional functionality and health benefits. Hydrolysis of ESN SiaMuc-glycoprotein was performed for 1 to 4 h and its effect on physicochemical properties, molecular weight (MW) distribution, SiaMuc-glycoprotein and glycopeptide integrity were determined. Other than improvement in solubility and bioavailability as SiaMuc-glycopeptide, results from SDS-PAGE revealed that MW of SiaMuc-glycoprotein decreased from 42.0-148.8 kDa to 17.7-142.7 kDa with increasing hydrolysis period. Further hydrolysis from maximized DH (90 min) showed an insignificant effect on the MW of ESN SiaMuc-glycopeptide and remained constant at 15.2 kDa. This highlights that enzymatic hydrolysis only influences macro SiaMuc-glycoprotein fractions (142.7, 115.3 and 102.7 kDa), while the majority of SiaMuc-glycopeptide fractions from 36.6-98.6 kDa remained intact. Conclusively, alcalase hydrolysis of ESN showed high recovery in the form of bioactive ESN SiaMuc-glycopeptide. Therefore, enzymatic biotechnology is an economic alternative applicable on ESN that broaden industrial utilization by reducing the MW without destroying the quality of bioactive SiaMuc-glycoprotein.

Recovery of value-added glycopeptides from edible bird's nest (EBN) co-products: enzymatic hydrolysis, physicochemical characteristics and bioactivity

BACKGROUND

Processing of edible bird's nest (EBN) requires extensive washing to remove impurities and produces huge amounts of EBN co-products, which contain mainly feathers with glycoproteins attached, which are usually discarded. This study was conducted to recover the valuable EBN glycoproteins from the waste material. Enzymatic hydrolysis was applied to recover EBN glycopeptides from EBN co-products (EBN_coP ) and processed cleaned EBN (EBN_clean ) was used as control, which were then freeze-dried into EBN hydrolysates (EBNh_coP and EBNh_clean , respectively).

RESULTS

The recovery yield for EBNh_clean and EBNh_coP were 89.09 ± 0.01% and 47.64 ± 0.26%, respectively, indicating nearly 50% of glycopeptide can be recovered from the waste material. Meanwhile, N-acetylneuraminic acid, a major acid sugar in EBN glycoproteins, of EBNh_coP increased by 229% from 58.6 ± 3.9 to 192.9 ± 3.1 g kg^-1 , indicating the enzymatic hydrolysis removed impurities and thus enhanced the N-acetylneuraminic acid content. Total soluble protein was more than 330 g kg^-1 for all the samples. Colour parameter showed that hydrolysate samples have greater L* (lightness) values. Chroma result indicates the intensity of all the samples were low (< 11). Fourier-transform infrared (FTIR) spectrum displayed that the EBNh_coP exhibited similar functional groups with EBNh_clean , indicating that the EBN_coP has similar functionality as EBN_clean . Significantly higher (P ≤ 0.05) 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) activities were reported in EBNh_coP after the enzymatic reaction.

CONCLUSION

EBNh_coP were successfully recovered from low value EBN_coP with enhanced antioxidant activities. The findings of this work are beneficial for the EBN industry to reduce wastage and enhance economic values of EBN co-products, both economically and nutritionally. © 2020 Society of Chemical Industry.

Effects of marbling on physical and sensory characteristics of ribeye steaks from four different cattle breeds

OBJECTIVE

Marbling or intramuscular fat (IMF) has been widely reported to directly impact the sensory acceptance of meat. This study was carried out to determine the physical and sensory characteristics of ribeye, Longissimus dorsi steaks obtained from four different cattle breeds namely Wagyu, Angus, Brahman, and Malaysian local beef, the Kedah-Kelantan (KK).

METHODS

The degree of marbling was determined by using an established combined camera-image analysis technique while instrumental texture determination was carried out by using Warner-Bratzler shear force analysis. Sensory evaluation of the beef steaks was performed following a quantitative descriptive analysis incorporating 10 trained consumer panelists.

RESULTS

Wagyu was found to possess the highest (p<0.05) percentage of IMF at 33.90% and the lowest shear force (raw = 5.61 N/mm2; cooked = 14.72 N/mm2) followed by Angus (20.87%), Brahman (12.17%), and KK (p<0.05, 6.86%). The difference in sensory properties of the four steaks was evident, with Wagyu appearing to be highly correlated with most sensory attributes measured namely sustained buttery, tooth-packing, chewiness, juiciness, tenderness, mouthfeel, oiliness, and overall acceptability. The Malaysian local beef, KK was found to be less acceptable (p<0.05), although most of its sensory attributes were found similar (p>0.05) in appearance, aroma, texture, juiciness, and flavour to the cooked steak from Angus and Brahman.

CONCLUSION

This present study demonstrated the role of IMF in determining the quality and sensory acceptance of beef from different cattle breeds. These data have provided new information and further understanding on the physical and sensory quality of Malaysian local beef.

Isolation, Purification and Characterization of Antioxidative Bioactive Elastin Peptides from Poultry Skin

Muscle-based by-products are often undervalued although commonly reported having a high amount of natural bioactive peptides. In this study, elastin was isolated from the protein of broiler hen skin while its hydrolysate was prepared using Elastase. Assessment of antioxidative properties of elastin-based hydrolysate (EBH) was based on three different assays; 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) radical, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical and metal chelating ability. The EBH was purified further using ultrafiltration, gel filtration and Reverse- Phase High-Performance Liquid Chromatography (RP-HPLC). The IC50 of ABTS radical activities for EBH were decreased as EBH further purified using ultrafiltration (EBH III; 0.66 mg/mL)>gel filtration (EB-II; 0.42 mg/mL)>RP-HPLC (EB-II4; 0.12 mg/mL). The sequential identification of the peptide was done by matrix-assisted laser desorption/ ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/ TOF-MS) of the potent fractions obtained from RP-HPLC (EB-II4). The presence of hydrophobic amino acids (Val and Pro) in the peptide sequences could potentially contribute to the high antioxidant activity of EBH. The sequences GAHTGPRKPFKPR, GMPGFDVR and ADASVLPK were identified as antioxidant peptides. In conclusion, the antioxidative potential from poultry skin specifically from elastin is evident and can be explored to be used in many applications such as health and pharmaceutical purposes.

Identification of two novel antioxidant peptides from edible bird's nest (Aerodramus fuciphagus) protein hydrolysates

Two novel antioxidant pentapeptides were isolated from EBN hydrolysates with a protective effect against H₂O₂-induced oxidative damage in cancer cell lines.

The effects of Cosmos caudatus (Ulam Raja) supplementation on bone biochemical parameters in ovariectomized rats

Cosmos caudatus (ulam raja) contains high mineral content and possesses high antioxidant activity which may be beneficial in bone disorder such as postmenopausal osteoporosis. The effects of C. caudatus on bone metabolism biomarkers in ovariectomized rats were studied. 48 Sprague-Dawley rats aged three months were divided into 6 groups. One group of rats was sham-operated while the remaining rats were ovariectomized. The ovariectomized rats were further divided into 5 groups: the control, three groups force-fed with C. caudatus at the doses of 100mg/kg, 200mg/kg or 300mg/kg and another group supplemented with calcium 1% ad libitum. Treatments were given 6 days per week for a period of eight weeks. Blood samples were collected twice; before and after treatment. Parameters measured were bone resorbing cytokine; interleukin-1 and the bone biomarkers; osteocalcin and pyridinoline. Serum IL-1 and pyridinoline levels were significantly increased in ovariectomized rats. Supplementation of C. caudatus was able to prevent the increase of IL-1 and pyridinoline in ovariectomized rats. Besides that, C. caudatus showed the same effect as calcium 1% on biochemical parameters of bone metabolism in ovariectomized rats. In conclusion, Cosmos caudatus was as effective as calcium in preventing the increase in bone resorption in ovariectomized rats.

Effect of different pretreatments on functional properties of African catfish (Clarias gariepinus) skin gelatin

Pretreatments with different types of alkali and acid were compared to determine their effects on gelatin extraction from African catfish (Clarias gariepinus) skin. The study was divided into three parts. In the first part, the skins were only treated with alkaline (Ca(OH)2 or NaOH) solution or pretreated with acetic acid solution. For second part, combination of alkali and acid pretreatment was carried out. For the third part, the skins were first treated with NaOH solution, followed by the treatment with acetic acid, citric acid or sulfuric acid solution. Functional properties including the yield of protein recovery, gel strength, viscosity, pH and viscoelastic properties were determined on gelatins obtained with different pretreatment conditions. Pretreatment with alkali removed noncollagenous proteins effectively, whilst acid pretreatment induced some loss of collagenous proteins. Combination of alkali and acid pretreatment not only removed the noncollagenous proteins and caused a significant amount of swelling, but also provided the proper pH condition for extraction, during which some cross-linkages could be further destroyed but with less breakage of intramolecular peptide chains. Pretreatment of catfish skins with 0.2 N NaOH followed by 0.05 M acetic acid improved yield of protein recovery, gel strength, viscosity, melting temperature and gelling temperature of gelatin extract.

ACE inhibitory activity of pangasius catfish (Pangasius sutchi) skin and bone gelatin hydrolysate

Skin and bone gelatins of pangasius catfish (Pangasius sutchi) were hydrolyzed with alcalase to isolate Angiotensin Converting Enzyme (ACE) inhibitory peptides. Samples with the highest degree of hydrolysis (DH) were separated into different fractions with molecular weight cut-off (MWCO) sizes of 10, 3 and 1 kDa, respectively and assayed for ACE inhibitory activity. Skin and bone gelatins had highest DH of 64.87 and 68.48 % after 2 and 1 h incubation, respectively. Results from this study indicated that by decreasing the molecular weight of fractions, ACE inhibitory activity was increased. Therefore, F3 permeates (MWCO < 1 kDa) of skin (IC50 = 3.2 μg/ml) and bone (IC50 = 1.3 μg/ml) gelatins possessed higher ACE inhibitory activity compared to their untreated gelatins and corresponding hydrolyzed fractions. In this study, the major amino acids were Glycine followed by Proline with an increased amount of hydrophobic amino acid content in F3 permeates of skin (4.01 %) and bone (5.79 %) gelatin. Digestion stability against gastrointestinal proteases did not show any remarkable change on ACE inhibition potency of these permeates. It was concluded that alcalase hydrolysis of P. sutchi by-products could be utilized as a part of functional food or ingredients of a formulated drug in order to control high blood pressure.

A review of fish-derived antioxidant and antimicrobial peptides: their production, assessment, and applications

Fishes are rich sources of structurally diverse bioactive compounds. In recent years, much attention has been paid to the existence of peptides with biological activities and proteins derived from foods that might have beneficial effects for humans. Antioxidant and antimicrobial peptides isolated from fish sources may be used as functional ingredients in food formulations to promote consumer health and improve the shelf life of food products. This paper presents an overview of the antioxidant and antimicrobial peptides derived from various fishes. In addition, we discuss the extraction of fish proteins, enzymatic production, and the techniques used to isolate and characterize these compounds. Furthermore, we review the methods used to assay the bioactivities and their applications in food and nutraceuticals.

Effect of retorting and oven cooking on the nutritional properties of beef frankfurters blended with palm oils

The effect of retorting and oven cooking on the nutritional properties of beef frankfurters blended with palm oil (PO), red PO35 and red PO48 were compared against the control beef fat treatment. Red PO oven-cooked beef frankfurters resulted in a significant loss of vitamin E from 538.5 to 287.5 microg after 6 months. Oven cooked sausages stored at -18 degrees C and retorted sausages stored for the 6 months of shelf studies resulted in more than 90% loss of alpha-carotene and beta-carotene in red PO beef frankfurters. Cholesterol was reduced at the range of 29.0-32.2 mg/100 g when beef fat was substituted with palm-based oils, in beef frankfurters. Differences of heat treatments did not significantly change THE cholesterol content, within all treatments. This study showed the potential of utilizing red palm oils as animal fat analogues in improving vitamin E, reducing cholesterol but not carotenes in beef frankfurters.

Protein quality of anchovy, mackerel and canned sardine samples

The protein nutritive value of anchovy, mackerel and canned sardine samples together with casein as a reference formulation were evaluated. Proximate composition, protein quality and protein digestibility were determined. Procedures for evaluation included Protein Efficiency Ratio (PER) using the rat bioassay and in vivo Apparent Digestibility (AD). Rats fed with canned sardine diet had the highest mean body weight (154.8±12.28g) while rats fed with anchovy diet had the lowest mean body weight (145.27±15.89g) with significant differences between all the groups. Mean body weight of rats fed with selected fish diet was higher compared to rats fed with casein diet. For PER value, canned sardine has the highest value (2.48), followed by anchovy (2.46) and mackerel (2.34). PER value for all selected fish is lower than that for casein (3.14). Mackerel had the highest value of in vivo AD (96.99%), followed by casein (96.96%), canned sardine (96.88%) and anchovy (91.29%). In conclusion, among the types of fish compared, sardine had the highest protein quality while mackerel showed the highest digestibility.

Chemical, physical and sensory properties of chicken frankfurters substituted with palm fats

Physico-chemical and sensory characteristics of frankfurters prepared with three types of palm fats (PF60: 40, PF70: 30 and PF80: 20) and palm olein (POo) at 20 and 25% of fat levels were studied. Incorporation of different fats at 20 and 25% did not affect the cooking yields of the frankfurters. Frankfurters incorporated with 25% POo showed the highest value of water-holding capacity (WHC) among eight formulations. The frankfurters containing POo showed the least cooking loss compared to those with palm fats. The incorporation of different type and level of fats resulted in significant changes in the colour (lightness, redness, yellowness) of frankfurters. Texture profiles of both raw and cooked frankfurters were found to be altered by the blending of different type and level of fats. In raw frankfurters, hardness for frankfurters mixed with palm fats were significantly higher than the one with POo but greater values for cohesiveness was observed in raw frankfurters blended with POo. Lowest chewiness was demonstrated by frankfurters mixed with 20% POo. Grilling increased the hardness values of all frankfurters. Contrary to the raw counterparts, cooked frankfurter with POo was the hardest among all formulations. Cohesiveness and chewiness was also found to be significantly higher for cooked frankfurters mixed with POo. Raw frankfurters with fat content of 25% showed greater value in hardness than those of 20%. However, there were no significant differences (P > 0.05) observed for all the texture profile attributes in cooked frankfurters due to fat levels. In sensory evaluation, frankfurters prepared with POo were found to be most acceptable by consumer panels as they scored the highest for hardness rating, chicken flavour, oiliness and overall acceptance attributes.

Quality of mechanically deboned chicken meat frankfurter incorporated with chicken skin

Four formulations were processed into frankfurters with different ratios of mechanically deboned chicken meat (MDCM) and cooked chicken skin (CCS) i.e. 80/0, 70/10, 60/20 and 50/30. The products were evaluated for proximate composition, cholesterol content, colour; 'L' value (lightness) and 'a' value (redness), percentage of cooking loss, physical measurements (shearforce-kgf and folding test), thiobarbituric acid value (TBA) and taste panel evaluation. The increment of CCS in the frankfurters increased the contents of moisture, ash, protein, fat, cholesterol, the lightness ('L' value) and redness ('a' value). After 3 months of frozen storage, the increment continued except for the moisture contents for formulations with 20 and 30% CCS. The lipid oxidation (TBA value) and cooking loss were lowered in formulations with CCS. After 3 months of frozen storage, TBA value decreased, while the cooking loss increased for all the formulations. The addition of CCS increased hardness of the frankfurters but affected folding ability, with formulation with 10% CCS scoring better grade. Sensory evaluation was carried out using 30 untrained panelists to evaluate aroma, colour, appearance, hardness, juiciness, chicken taste, oily taste, rancid taste and overall acceptance of the products. The addition of CCS in the frankfurters at 10 and 20% resulted in products with taste and texture that were acceptable after 3 months of frozen storage.

Replacement of animal fat with fractionated and partially hydrogenated palm oil in beef burgers

Four formulations of burgers, prepared with 65% lean meat and 15% fat consisting of RBD palm stearin (PS), Socfat 4000P and Socfat 4100P and beef fat (BF) as control were evaluated for solid fat content (SFC), slip melting point (SMP), cooking loss, proximate analysis (moisture, fat and protein), colour, i.e. lightness ('L'), redness ('a') and yellowness ('b'), free fatty acid (FFA), iodine value (IV), thiobarbituric acid (TBA) and texture profile analysis (TPA). Sensory evaluation was carried out for texture, juiciness, aroma, oiliness and overall acceptance. SFC and SMP for raw and cooked SF4000P beef burgers were closest to BF control burgers, falling into the range of 35-40 degrees C. Cooking loss was highest for PS burgers, there were no significant differences (P > 0.05) amongst BF, SF4000P and SF4100P burgers. Proximate analysis on raw burgers showed SF4000P to contain high fat and lowest moisture contents. Objective textural measurements using texture profile analysis (TPA) for all cooked burgers showed no significant differences (P > 0.05) for springiness and cohesiveness. Variation of values among the formulations for hardness, gumminess and chewiness are explained by the differences of SFC for beef burgers with various types of fats. Raw and cooked PS burgers have the lightest 'L' values compared with other fat-substituted burgers while BF, SF4000P and SF4100P indicated no significant differences (P > 0.05) for 'L', 'a' and 'b' values. Beef fat showed the highest amount of free fatty acids (FFA) compared to palm oil samples. For the iodine value (IV), SF4000P showed the highest value which means that it contained the highest level of unsaturated fatty acids followed by PS, BF and SF4100P successively. SF4000P had the highest TBA values followed successively by BF, PS and SF4100P. For sensory evaluation, PS burgers had the least oily taste. This may be due to its high cooking loss. Taste panelists could not differentiate burgers with substituted vegetable fats against the control burgers.

Effect of non-meat proteins, soy protein isolate and sodium caseinate, on the textural properties of chicken bologna

Nine formulations were processed into bologna with different ratios of soy protein isolate (SPI):sodium caseinate (SCA), i.e. 1:1, 1:2.5, 1:5, 5:1, 5:2.5, 5:5, 10:1, 10:2.5 and 10:5. The products were evaluated for yields, emulsion stability, physical measurements (shearforce-kgf and folding test) and taste panel evaluation. Formulations with 5:1 and 5:5 SPI:SCA had lower liquid loss resulting in higher yields while the others had poor emulsion stability and high liquid loss. Firmer texture was exhibited by formulations 1:1, 5:1 and 10:1 SPI:SCA but formulation with 1:1 SPI:SCA showed better gelation followed by 1:2.5, 1:5, 5:1, and 5:2.5. The other formulations had poor gelation and binding properties, especially formulation with 10:5 SPI:SCA. Sensory evaluation was carried out using 30 untrained panelists. Attributes evaluated were aroma, texture, chewiness, juiciness, saltiness, chicken taste and overall acceptance. Formulation with 5:1 SPI:SCA was more acceptable for texture, chicken taste and overall acceptance while formulation with 1:1 SPI:SCA was more acceptable for the chewiness, juiciness and saltiness attributes. There was no significant difference (P > 0.05) in aroma attribute, for all formulations.

The nutritional value of some processed meat products in Malaysia

Per capita consumption of meat and meat products in Malaysia more than doubled from 15.70 kg in 1970 to 35.71 kg in 1990. This increase in meat consumption is mainly due to the rapid development and wide acceptance of value added meat and poultry products amongst Malaysian consumers. Meat products such as burgers, sausages, hotdogs and nuggets are widely accepted and consumed by all ethnic groups at home as well as in the fast food restaurants. The significant expansion of the fast food industry and the increase consumption of processed meat products makes it necessary for a re-evaluation of the nutritional quality of popular meat products currently available in the market. This review paper described the quality of some processed meat products, their proximate composition, meat quality, use of non meat proteins and binders, and the use of additives in the formulation of burgers, frankfurters, nuggets, bologna, chicken and beef balls. Preliminary results on the protein efficiency ratio of local meat products seemed favourable but this study is limited to only one laboratory. In vivo and in vitro protein digestibility studies indicated high values on the digestibility of locally manufactured meat products. Proximate analysis of the raw materials used in the formulation of such products showed many with high fat and low protein contents being utilized. The meat content was lower than the minimum amount stated by the food regulation. This paper concludes that due to lack of information and studies on the nutritional composition of processed meat products, concerned bodies should take positive steps to generate reliable data to elucidate the actual nutritional composition of such products. It is also observed that many by-products from the animal industry from non-conventional sources are increasingly being utilized in the manufacture of processed meat product.