Development of a simple in vitro assay for estimating net rumen acid load from diet ingredients

The objective of these experiments was to develop a simple in vitro technique for evaluating the production and neutralization of acid as feeds ferment in the rumen. An in vitro approach was adopted to eliminate animal factors. The procedure was based on the method of Tilley and Terry, with some modifications developed in this project. Residual acidity (acidogenicity value) was determined by the dissolution of Ca from CaCO3 powder added to the media at the end of 24-h incubations. Acidogenicity values (AV) were higher when 20% strength buffer was used, while lowering buffer pH increased values, equally across all feeds. There was no effect of donor animal diet, but considerable day-to-day variation in the fermentation activity of rumen fluid. This variation likely reflected the substrate preferences of differing microbial populations, so that several standard feeds may be required to account for this effect. A series of 28 diverse feed ingredients was evaluated for AV using a mixture design, with 85 combinations of ingredients: 100% of each ingredient (n = 28); 50% of each ingredient and an equal mixture of all others (n = 28); equal mixture of all ingredients, excluding one (n = 28); and an equal mixture of all ingredients (n = 1). The effects of most ingredients on AV were essentially linear, though some extreme ingredients showed nonlinear effects. Protein sources had low AV, forages intermediate AV and starchy feeds high AV. Calcium contained within feeds contributed to AV, particularly for legumes, sugar beet pulp, and citrus pulp, and must be accounted for.     

Determination of inorganic arsenic species (As and As) in muscle tissues of fish species by electrothermal atomic absorption spectrometry (ETAAS)

Arsenic speciation was carried out in muscle tissues of freshwater fish species. Inorganic arsenic species (As³⁺and As⁵⁺) were extracted with chloroform, prior to microwave assisted digestion with concentrated HClO₄ and Fe₂(SO₄)₃. The extracted As³⁺ and As⁵⁺ were determined by electrothermal atomic absorption spectrometry (ETAAS). The accuracy of the technique was evaluated by using certified reference material DORM-2. The limit of detection of the method was 0.004 and 0.005 μg/g for As³⁺ and As⁵⁺, respectively. The mean relative standard deviation values (RSD) in real sample analysis were 1.90 and 3.92 for As³⁺ and As⁵⁺, respectively. The results demonstrated the suitability of the procedure for screening and quantification of As species in biological samples. The mean concentration of As³⁺ and As⁵⁺ in muscle tissues of studied fish species ranged from 1.19 to 2.05 and 0.17 to 0.46 μg/g, respectively. The contribution of the daily intake of inorganic As, based on the consumption of 250 g fresh fish muscles/body weight/day was found in the range of 1.21–1.91 μg/kg/day.     

Industry-Relevant Approaches for Minimising the Bitterness of Bioactive Compounds in Functional Foods: A Review

Functional foods, with their synergistic health benefits that go beyond just being a source of individual nutrients, present challenges to the traditional ‘nutrition’ view of foods. Consumers demand proven health benefits without compromising flavour, taste and colour. A successful functional food must offer nutrients, specific health-promoting functionality and desirable sensory attributes. Attempts to increase the intake of desirable bioactive compounds are driven by the need to deliver optimal bioactivity to consumers for disease prevention and health enhancement. Increasing the bioactive concentration in foods often leads to bitterness, particularly when incorporating bioactive phytochemicals. This article provides an overview of the strategies which can be used for food bitterness reduction, with an emphasis on those approaches which are industrially relevant and economically feasible, i.e. tailored food formulation, processing and delivery technology approaches. Solutions for reducing bitterness from phytochemicals in food are proposed, including blocking, inhibiting, suppressing, minimising and masking mechanisms. The potential of encapsulation and non-encapsulation approaches for functional food applications is highlighted, and their effect in improving stability, bioactivity, bioaccessibility and bioavailability is addressed.     

Spray-Drying Microencapsulation of Polyphenol Bioactives: A Comparative Study Using Different Natural Fibre Polymers as Encapsulants

This research explores the spray-drying microencapsulation of polyphenols (PPs), quercetin and vanillin, using four different fibre polymers as encapsulants (sodium alginate, methyl β-cyclodextrin (MβCD), hydroxypropylmethyl cellulose (HPMC) and inulin). The microstructure, physico-chemical properties, PP content and reconstitution properties in water of the spray-dried powders were systematically evaluated and compared. Techniques used for powder characterisation were scanning electron microscopy, N₂ physisorption, Fourier transform infrared (FT-IR) spectroscopy and water activity measurements. High-performance liquid chromatography and viscosity measurements were used to characterise the solutions obtained by reconstitution of the spray-dried powders in methanol or water, respectively. Results show that the type of encapsulant strongly influenced powder morphology, powder surface area and encapsulation efficiency of PPs. Powders prepared using sodium alginate and MβCD possessed more spherical particle shape, smaller average particle size and higher specific surface area than those using HPMC or inulin as encapsulants. For each encapsulant, higher encapsulation efficiencies were achieved for vanillin (37–53 %) than quercetin (9–19 %). Encapsulation efficiencies were inulin?>?MβCD?>?HPMC?>?sodium alginate for vanillin-containing powders. Inulin, MβCD and sodium alginate all gave similar encapsulation efficiencies for quercetin-containing powders. All powders possessed low water activity and excellent dissolution properties in water. Therefore, spray-drying microencapsulation using natural fibre encapsulants is a feasible approach for delivering the dual health benefits of PPs and dietary fibre to consumers. Spray-drying yields a product in a convenient powder form, which can be reconstituted in water or other beverages for direct consumption or used as a functional additive in solid food systems.     

The effect of routing flexibility on a flexible system of integrated manufacturing

Flexible manufacturing systems (FMSs) have gained consideration due to their ability to produce customised and an increasing variety of products with shorter life cycles. A considerable amount of research has been done on manufacturing flexibility from different angles. There are many different types of manufacturing flexibility being reported in the literature, and routing flexibility is one of them. The paper focuses on the study of routing flexibility in a flexible system of integrated manufacturing (FSIM) from the view of real-time control strategies. However, flexibility incurs cost hence a judicious decision is required for implementing the right level of flexibility under a different operating environment. The paper studies the impact of routing flexibility and control strategies on the performance of FSIM. The application of discrete event simulation and Taguchi's method is applied to study the various factors contributing to FSIM performance and identifies the vital parameters for improving performance. Furthermore, the most significant factor is determined by using the analysis of variance (ANOVA). The result shows that increasing routing flexibility cannot be treated as a key role in system improvement. It is also found that there is the influence of control strategies on the performance of FSIM. Finally, it is observed that, the impact on the system performance due to the system load condition is the largest, and that of the number of pallets is the smallest.     

Inventory performance of some supply chain inventory policies under impulse demands

This paper attempts to study the impact of impulsive demand disturbances on the inventory-based performance of some inventory control policies. The supply chain is modelled as a network of autonomous supply chain nodes. The customer places a constant demand except for a brief period of sudden and steep change in demand (called demand impulse). Under this setting, the behaviour of each inventory policy is analysed for inventory performance of each node. It is found that the independent decision-making by each node leads to a bullwhip effect in the supply chain whereby demand information is amplified and distorted. However, under a scenario where the retailer places a constant order irrespective of the end customer demand, the inventory variance was actually found to decrease along the supply chain. The variance of the inventory remained constant along the chain when only the actual demands are transmitted by each node. The results also showed that the inventory policy which is best for one supply chain node is generally less efficient from a supply chain perspective. Moreover, the policy which performs poorly for one node can be most efficient for the supply chain. In a way, our results also provide a case for coordinated inventory management in the supply chain where all members prepare a joint inventory management policy that is beneficial for all the supply chain nodes. The results have significant industrial implications.     

Framework for flexibility in dynamic supply chain management

Effective Supply Chain Management (SCM) is a pivotal issue in the dynamically changing business environment. Dynamic SCM requires integrated decision-making amongst autonomous chain partners with effective decision information synchronization amongst them. By exploiting flexibility in supply chain structures, better performance can be achieved. Similarly, by judiciously employing decision flexibility and the associated dynamic control amongst autonomous supply chain nodes, many improvements are possible. The paper presents a study on the role of different flexibility options (i.e. no flexibility, partial flexibility and full flexibility) in a dynamic supply chain model based on some key parameters and performance measures. Supply chain flexibility has significant potential and needs a greater research attention. The paper attempts to advance the knowledge of dynamic control on effective flexibility exploitation in the context of dynamic supply chains. A simulation model of a dynamic supply chain is used for this purpose. The key results are highlighted along with industry implications. Here each supply chain node involves decision-making. Based on the order and sample information available from the immediate buyers or customers, the supplier selection decisions are dynamically made. A seemingly good decision at a stage based on local information often ends up as detrimental not only to the total chain cost, but also to the total costs of the node itself. These observations are important for the designers and managers of the flexible supply chain systems to arrive at appropriate types and a judicious level of flexibility to attain significant improvements in total cost reduction. The modelling of dynamic supply chains with a focus on flexibility can offer enormous potential to the industry. This paper addresses this interesting and challenging domain.