High intrinsic biosorption efficiency of cattle manure on Cr(VI): a potential low-cost fibre-rich biosorbent

Fibre-rich manure derived from grass-fed cattle showed significantly higher intrinsic sorption efficiency on Cr(VI) solution as compared to corncob, sawdust and cogon grass. This observation could be attributed to the ligneous nature and rough surface morphology of the cattle manure. Four-factor, three-level, face-centred composite design (FCCD) suggested the process was greatly affected by initial pH of the solution, contact time and sorbent dosage (p50% adsorption efficiency. It is predicted that both physisorption and chemisorption are involved in the sorption process

Physicochemical and sensory analyses of high fibre bread incorporated with corncob powder

The primary objectives of the present work were to produce corncob powder (CCP) from corncobs and incorporate the CCP into bread formulation in order to develop high fibre bread, and to investigate the physicochemical and sensory properties of the produced high fibre bread (HFB). The corncobs were collected and washed before they underwent the grinding and drying processes. The obtained CCP was incorporated into the bread formulation in three different proportions (5, 10 and 20%) to partially substitute bread flour in the formulation. All three bread samples and the control (0% CCP in the formulation) were analysed to obtain their physicochemical and sensory properties. The incorporation of CCP significantly affected the texture, colour and volume attributes of the produced breads. Increasing the content of CCP in the formulation was found to be responsible for firmer, smaller and darker bread loaves as compared to the composite bread samples. The bread formulation incorporated with 10% CCP had the highest mean scores (7.00) of overall acceptability among all the other formulations, and it was comparable to the commercial breads in the current market

Production, safety, health effects and applications of diacylglycerol functional oil in food systems: a review

Diacylglycerol (DAG) is a world leading anti-obesity functional cooking oil synthesized via structural modification of conventional fats and oils. DAG exits in three stereoisomers namely sn-1,2-DAG, sn-1,3-DAG, and sn-2,3-DAG. DAG particularly sn-1,3-DAG demonstrated to have the potential in suppressing body fat accumulation and lowering postprandial serum triacylglycerol, cholesterol and glucose level. DAG also showed to improve bone health. This is attributed to DAG structure itself that caused it to absorb and digest via different metabolic pathway than conventional fats and oils. With its purported health benefits, many studies attempt to enzymatically or chemically synthesis DAG through various routes. DAG has also received wide attention as low calorie fat substitute and has been incorporated into various food matrixes. Despite being claimed as healthy cooking oil the safety of DAG still remained uncertain. DAG was banned from sale as it was found to contain probable carcinogen glycidol fatty acid esters. The article aims to provide a comprehensive and latest review of DAG emphasizing on its structure and properties, safety and regulation, process developments, metabolism and beneficial health attributes as well as its applications in the food industry

Microtiter miniature shaken bioreactor system as a scale-down model for process development of production of therapeutic alpha-interferon2b by recombinant Escherichia coli

Background: Demand for high-throughput bioprocessing has dramatically increased especially in the biopharmaceutical industry because the technologies are of vital importance to process optimization and media development. This can be efficiently boosted by using microtiter plate (MTP) cultivation setup embedded into an automated liquid-handling system. The objective of this study was to establish an automated microscale method for upstream and downstream bioprocessing of α-IFN2b production by recombinant Escherichia coli. The extraction performance of α-IFN2b by osmotic shock using two different systems, automated microscale platform and manual extraction in MTP was compared. Results: The amount of α-IFN2b extracted using automated microscale platform (49.2 μg/L) was comparable to manual osmotic shock method (48.8 μg/L), but the standard deviation was 2 times lower as compared to manual osmotic shock method. Fermentation parameters in MTP involving inoculum size, agitation speed, working volume and induction profiling revealed that the fermentation conditions for the highest production of α-IFN2b (85.5 μg/L) was attained at inoculum size of 8%, working volume of 40% and agitation speed of 1000 rpm with induction at 4 h after the inoculation. Conclusion: Although the findings at MTP scale did not show perfect scalable results as compared to shake flask culture, but microscale technique development would serve as a convenient and low-cost solution in process optimization for recombinant protein

Physicochemical properties and crystallisation behaviour of bakery shortening produced from stearin fraction of palm-based diacyglycerol blended with various vegetable oils

The stearin fraction of palm-based diacylglycerol (PDAGS) was produced from dry fractionation of palm-based diacylglycerol (PDAG). Bakery shortening blends were produced by mixing PDAGS with either palm mid fraction, PMF (PDAGS/PMF), palm olein, POL(PDAGS/POL) or sunflower oil, SFO (PDAGS/SFO) at PDAGS molar fraction of XPDAGS = 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%. The physicochemical results obtained indicated that C16:0 and C18:1 were the dominant fatty acids for PDAGS/PMF and PDAGS/POL, while C18:1 and C18:2 were dominant in the PDAGS/SFO mixtures. SMP and SFC of the PDAGS were reduced with the addition of PMF, POL and SFO. Binary mixtures of PDAGS/PMF had better structural compatibility and full miscibility with each other. PDAGS/PMF and PDAGS/SFO crystallised in β′+β polymorphs in the presence of 0.4–0.5% PDAGS while PDAGS/POL resulted in β polymorphs crystal. The results gave indication that PDAGS: PMF at 50%:50% and 60%:40% (w/w) were the most suitable fat blend to be used as bakery shortening

Rheological properties, textural properties, and storage stability of palm kernel-based diacylglycerol-enriched mayonnaise

The effect of replacement of soybean oil (SBO) with 0, 5, 10, 15, and 20% palm kernel based-diacylglycerol (PKDG) which were referred to as SD1000, SD9505, SD9010, SD8515, and SD8020 formulations, respectively, on the rheological properties, textural properties, and storage stability of mayonnaise were evaluated in this study. Emulsion stability results demonstrated no significant differences (P > 0.05) among all formulations except SD8020 which exhibited diminished emulsion stability. In terms of textural properties, both SD9010 and SD8020 showed closer textural characteristics compared with control. Microstructure evaluation of all mayonnaise formulations revealed significant increases in oil droplet diameter in tandem with increasing PKDG concentration. For rheological properties, all mayonnaise formulated displayed similar gel-like behavior with greater storage modulus (G') than loss modulus (G”) and loss tangent (tan δ) less than 0.3. Results indicated that up to 10% PKDG was suitable to be incorporated in healthy mayonnaise formulation. Both SD9505 and SD9010 were subsequently evaluated for their stability throughout a 2-month storage period. All mayonnaise displayed satisfying stability during storage with gradual increment in peroxide value, free fatty acid level, and G'G” crossover value except control. Additionally, an insignificant change in viscoelastic properties (P > 0.05) was observed after storage for all formulations examined. Practical applications: This present work has three main practical applications: (i) enable the incorporation of PKDG as a functional ingredient into a mayonnaise system; (ii) provide knowledge and understanding of the physicochemical, rheological, and textural properties of PKDG-enriched mayonnaise; and (iii) give insight into the storage stability of PKDG-incorporated mayonnaise throughout the 2-month storage period

Review on the current state of diacylglycerol production using enzymatic approach

Enzymatic production of diacylglycerol (DAG)-enriched oil has been investigated extensively due to its health benefits with total annual sales of approximately USD 200 million in Japan since its introduction in the late 1990s till 2009. Enzymatic catalysis had been proven to exhibit improved results with respect to yield, purity, reaction time, and stability in comparison with chemical catalysis. The cost of the enzymes, however, is the main hurdle to the widespread use of enzyme for commercial DAG production. This paper attempts to review and summarize various lipase-mediated technological methods for DAG production. Critical aspects such as process considerations on DAG synthesis, mass transfer limitations as well as kinetic mechanism models developed for each enzymatic approach in DAG synthesis are also presented and discussed. In addition, possible reactor configurations were evaluated, if lipase-assisted DAG production is to be technically and economically feasible at an industrial scale

Modeling and optimization of lipase-catalyzed partial hydrolysis for diacylglycerol production in packed bed reactor

Response surface methodology (RSM) was employed to optimize the process variables namely packed bed height (cm) and flow rates (ml/min) on diacylglycerol (DAG) production via partial hydrolysis of palm oil using immobilized Rhizomucor miehei lipase in packed bed reactor (PBR). Quadratic models were successfully developed for both DAG(y) and unhydrolyzed triacylglycerol ((un)TAG) with determination coefficient (R2) of 0.9931 and 0.9986, respectively coupled with insignificant lack of fit (p > 0.05). Optimal conditions for DAG synthesis were evaluated to be 10 cm packed bed height and 3.8 ml/min flow rate. Immobilized enzyme can be reused up to 10 times without significant changes in enzymatic activity. The partial hydrolysis under studied was found to be mass transfer-controlled

Production of y-cyclodextrin by Bacillus cereus cyclodextrin glycosyltransferase using extractive bioconversion in polymer-salt aqueous two-phase system

Aqueous two-phase system (ATPS) extractive bioconversion provides a technique which integrates bioconversion and purification into a single step process. Extractive bioconversion of gamma-cyclodextrin (γ-CD) from soluble starch with cyclodextrin glycosyltransferase (CGTase, EC 2.4.1.19) enzyme derived from Bacillus cereus was evaluated using polyethylene glycol (PEG)/potassium phosphate based on ATPS. The optimum condition was attained in the ATPS constituted of 30.0% (w/w) PEG 3000 g/mol and 7.0% (w/w) potassium phosphate. A γ-CD concentration of 1.60 mg/mL with a 19% concentration ratio was recovered after 1 h bioconversion process. The γ-CD was mainly partitioned to the top phase (YT = 81.88%), with CGTase partitioning in the salt-rich bottom phase (KCGTase = 0.51). Repetitive batch processes of extractive bioconversion were successfully recycled three times, indicating that this is an environmental friendly and a cost saving technique for γ-CD production and purification