Effect of Proteolytic Enzymes (Bromelain and Papain) on Sensory and Chemical Quality of Sukuti (an Indigenous Dried Meat Product of Nepal)

The present work was undertaken to compare the effect of bromelain and papain on the sensory quality of sukuti (Nepalese indigenous dried buffalo meat). Buffalo lean meat (round cut) was purchased from the local market of Dharan and used for the preparation of sukuti after injection of 10% m/m enzyme (bromelain and papain) solution at the concentration (0-100 mg/L) and resting for 4h followed by drying at 65°C up to the moisture of 5%. The optimized concentration of each enzyme was selected by sensory evaluation based on color, flavor, texture, and overall acceptability. The proximate composition, collagen content, and collagen solubility were studied for two optimized samples with enzyme treatment and control. The best tenderizing effect of papain and bromelain enzyme was found at 40 mg/L and 10 mg/L respectively from the sensory analysis and the sensory attributes for these concentrations were significantly (p<0.05) higher than other samples. The soluble collagen content increased from 0.44 mg/g tissue in untreated meat to 0.52 for bromelain treated and to 0.98 mg/g for papain treated samples. The collagen solubility for the untreated sample was 4.74% which increases to 7.80% for bromelain and 13.82% for papain-treated samples. The protein content of optimized papain and bromelain treated samples was significantly decreased (p<0.05) from 82.44 to 80.25% and 81.43% respectively for papain and bromelain treated samples. There were no significant changes in fat, ash, and moisture on enzyme treatment.

Solid-State Hydrolysis (SSH) Improves the Nutritional Value of Plant Ingredients in the Diet of Mugil cephalus

The possibility of improving the nutritional quality of plant byproducts (brewers’ spent grain and rice bran) through an enzyme treatment was tested in a formulated feed for grey mullet (Mugil cephalus). The enzyme treatment was carried out by Solid-State Hydrolysis (SSH) using a commercial preparation including carbohydrases and phytase. A feed prepared without the treatment and a commercial feed for carp were used as controls. In a preliminary short-term trial carried out at laboratory facilities, fish receiving the enzyme-treated feed showed significant improvement in both FCR and SGR when compared to those obtained with the untreated diet, although both experimental diets presented worse values than those obtained with the commercial feed. Different metabolic indicators including higher values of muscle glycogen and plasmatic triglycerides supported the positive effect of the enzyme treatment on the nutritional condition of the fish over those fed on the diet containing non-treated ingredients. Results of growth and feed efficiency that were obtained in a second long-term trial developed for 148 days under real production conditions evidenced the equivalence among the experimental and commercial diets and confirmed that enzyme pretreatment of plant ingredients by SSH may be a useful procedure to improve the nutritive value of high fiber plant byproducts when included in practical diets for this species and others with similar nutritional features.

Effect of transglutaminase on fresh cheese quality propertises using citric acid as a coagulant

The purpose of this study was to evaluate the effect of microbial transglutaminase (MTGase) on cheese quality properties using citric acid as a coagulant agent. The experimental results showed that citric acid has a temperature-dependent ability to agglomerate milk proteins. The process of protein coagulation at 50°C by citric acid (2.0%) gave fresh cheese with yield production (% H), dry matter content (% TS) and cheese solids yield (CSY) of 12.81%, 41.17%, 38.73%, respectively. The reconstituted milk was incubated with MTGase under different conditions of enzyme concentration (0-6.0 IU / g protein), processing temperature (30-50 °C) and time (60-180 min.). Enzyme treatment at 37 °C with enzyme concentration of 2 IU/g protein for 2 hrs showed the highest values of yield (15.03%), dry matter content (46.96%) and cheese solids yield (46.83%). Analytical results of the sensory score, acidity, whey separation and color difference of fresh cheese samples during storage (28 days) showed that using MTGase better maintained the quality of the product. Furthermore, MTGase also improved water holding capacity (reduced whey separation) during storage and did not affect the color of fresh cheese products. Moreover, the physicochemical and microbiological parameters of the product were also determined. The results showed that the quality of fresh cheese coagulated by citric acid met CODEX STAN 221-2001 for unripened cheese including fresh cheese.

A New Test of Filterability for Unprocessed Wines Evaluation of the Enzyme Efficiency

A new Test of Filterability has been developed. Measurements carried out with different types of wines indicate that the new filterability index is a useful tool for understanding and predicting the propensity to fouling of treated or untreated wines, e.g. with or without enzyme addition. The measurement method used in the Test of Filterability, requires only one type of membrane for all types of wine, and uses the same equipment as the traditional Fouling Index. Numerous trials have demonstrated that the filtration of wines is governed by standard blocking law. The definition of the new Test of Filterability, based on this filtration law, is proposed. The choice of membrane and the selection of the optimal pore size were based on the results of the experiments. Current methods used for the determination of fouling properties in wine filtration have been developed for the membrane filtration of small quantities of suspended matter. Enzyme treatment is a process often used in wine clarification. The new Test of Filterability indicates the best conditions for the filtration of all types of wines. The test is easy to implement and has been validated with various wines. This new Test of Filterability is an important tool for winemakers as it constitutes a simplified test of a wine's filterability. The new test may also be used to determine the filtration process that is best adapted to each wine while reducing the number of operations. The same approach may be adopted for the filtration of other liquids.

Influence of Commercial Protease and Drying Process on Antioxidant and Physicochemical Properties of Chicken Breast Protein Hydrolysates

Different proteases can be applied to produce certain bioactive peptides. This study focused on the effects of some commercial proteases and drying processes on the physical, chemical, and biological properties of chicken breast hydrolysates (CBH). Chicken breast hydrolyzed with Alcalase® presented a higher degree of hydrolysis (DH) than papain. Moreover, the treatment with Alcalase®, followed by papain (A-P), was more proficient in producing antioxidant activities than a single enzyme treatment. Conditions comprising 0.63% Alcalase® (w/w) at pH 8.0 and 52.5 °C for 3 h, followed by 0.13% papain (w/w) at pH 6.0 and 37 °C for 3 h, resulted in the highest yields of DH and peptide contents. The spray-dried microencapsulated powder improved the physicochemical properties including moisture content, color measurement, solubility, and particle morphology. In summary, the dual enzyme application involving the hydrolysis of Alcalase® and papain, coupled with the spray-drying process, could be used to produced antioxidant CBH.

The effect of Indigofera Leaf Flour (Indigofera Sp.) with Cocktail Enzymes Treatment in Male Ducks Feed on Growth Performance

This experimental study aims to evaluate the use of Indigofera leaves that have undergone cocktail enzyme treatment in male Mojosari duck feed. The research treatment was using Indigofera leaves due to enzyme cocktail treatment on male Mojosari duck feed with four levels: 0, 5, 10 and 15% of total feed, with six replications (@ five ducks) using 120 ducks in a completely randomized design. The variables measured and observed in this study were the production performance of male ducks, which included feed consumption, body weight growth, feed conversion. The research results were processed by analysis of variance (ANCOVA) because the coefficient of variation in initial body weight was 17.7%. The results showed that the addition of Indigofera leaf meal to the feed of male Mojosari ducks tended to reduce feed consumption (P<0.01) and body weight gain (P<0.05) but did not increase the FCR value (P>0.05). Indigofera flour needs to be processed first with a cocktail enzyme treatment to improve its nutritional quality so that it can be used as feed for ducks in larger quantities. Male Mojosari ducks that are kept need to be harvested at more than seven weeks to get a higher harvest weight.

Glycan detecting tools developed from the Clostridium botulinum whole hemagglutinin complex

Lectins are proteins with the ability to recognize and bind to specific glycan structures. These molecules play important roles in many biological systems and are actively being studied because of their ability to detect glycan biomarkers for many diseases. Hemagglutinin (HA) proteins from Clostridium botulinum type C neurotoxin complex; HA1, HA2, and HA3 are lectins that aid in the internalization of the toxin complex by binding to glycoproteins on the cell surface. HA1 mutants have been previously reported, namely HA1 W176A/D271F and HA1 N278A/Q279A which are specific to galactose (Gal)/N-acetylgalactosamine (GalNAc) and N-acetylneuraminic acid (Neu5Ac) sugars, respectively. In this study, we utilized HA1 mutants and expressed them in complex with HA2 WT and HA3 WT to produce glycan detecting tools with high binding affinity. Particularly, two types were made: Gg and Rn. Gg is an Alexa 488 conjugated lectin complex specific to Gal and GalNAc, while Rn is an Alexa 594 conjugated lectin complex specific to Neu5Ac. The specificities of these lectins were identified using a glycan microarray followed by competitive sugar inhibition experiments on cells. In addition, we confirmed that Gg and Rn staining is clearly different depending on cell type, and the staining pattern of these lectins reflects the glycans present on the cell surface as shown in enzyme treatment experiments. The availability of Gg and Rn provide us with new promising tools to study Gal, GalNAc, and Neu5Ac terminal epitopes which can aid in understanding the functional role of glycans in physiological and pathological events.

Development of a Simple Spheroid Production Method Using Fluoropolymers with Reduced Chemical and Physical Damage

Establishing an in vitro–based cell culture system that can realistically simulate in vivo cell dynamics is desirable. It is thus necessary to develop a method for producing a large amount of cell aggregates (i.e., spheroids) that are uniform in size and quality. Various methods have been proposed for the preparation of spheroids; however, none of them satisfy all requirements, such as cost, size uniformity, and throughput. Herein, we successfully developed a new cell culture method by combining fluoropolymers and dot patterned extracellular matrix substrates to achieve size-controlled spheroids. First, the spheroids were spontaneously formed by culturing them two-dimensionally, after which the cells were detached with a weak liquid flow and cultured in suspension without enzyme treatment. Stable quality spheroids were easily produced, and it is expected that the introduction and running costs of the technique will be low; therefore, this method shows potential for application in the field of regenerative medicine.