Influence of Cultivation Conditions on the Production of a Thermostable Extracellular Lipase from Amycolatopsis Mediterranei DSM 43304

Among several lipase producing actinomycete strains screened, Amycolatopsis mediterranei DSM 43304 was found to produce a thermostable, extracellular lipase. Culture condition and nutrient source modification studies involving carbon sources, nitrogen sources, incubation temperature and medium pH were carried out. Lipase activity of 1.37 ± 0.103 IU/ml of culture medium was obtained in 96 h at 28 °C and pH 7.5 using linseed oil and fructose as carbon sources and a combination of phytone peptone and yeast extract (5:1) as nitrogen sources. In optimal culture conditions the lipase activity was enhanced 12-fold with a 2-fold increase in lipase specific activity. The lipase showed maximum activity at 60 °C and pH 8.0. The enzyme was stable between pH 5.0–9.0 and temperatures up to 60 °C. Lipase activity was significantly enhanced by Fe3+ and strongly inhibited by Hg2+. Li+, Mg 2+ and PMSF significantly reduced lipase activity, whereas other metal ions had no significant effect at 0.01 M concentration. A. mediterranei DSM 43304 lipase exhibited remarkable stability in the presence of a wide range of organic solvents at 25% (v/v) concentration for 24h. These features render this novel lipase attractive for potential biotechnological applications in organic synthesis reactions

Predicting Quality Attributes and Waste of Strawberry Packed Under Modified Atmosphere Throughout the Cold Chain

Modified Atmosphere Packaging (MAP) is used commercially to extend the shelf life of strawberries. The attainment of desired gas (O2, CO2) concentrations inside MAP relies on the product respiration and the mass transfer through packaging and will affect the quality. The objective of this work is to build a mathematical model for strawberries to assess the effect of the uncertainties on headspace gas concentration and quality: 1) cold chain related temperature and relative humidity variations and 2) variability associated to product respiration and quality based on literature. Weight loss was more influenced by the cold chain storage conditions (temperature and RH) whereas spoilage had similar influence of cold chain conditions and product parameters. Waste generated in the cold chain was estimated from industrial standard weight loss and spoilage thresholds. A sensitivity analysis of the stochastic MAP model showed the influence of input parameters on the quality pointing to interventions associated to a reduction of the respiration rate (e.g. modification of packaging) and reduction of water transfer (e.g. coating) may prove more successful than other interventions to which the waste generation of this product is not so sensitive to. As a conclusion this work presents a toolbox to interpret cold chain data: 1) develop mathematical models to predict fate of quality 2) simulate cold chain conditions allowing for uncertainty 3) estimate the waste generation kinetics based in quality criteria and thresholds 4) perform a sensitivity analysis to identify most sensitive technological parameters 5) identify interventions that will affect those technological parameters

Predicting quality attributes of strawberry packed under modified atmosphere throughout the cold chain

Modified Atmosphere Packaging (MAP) is used commercially to extend the shelf life of strawberries. The attainment of desired gas (O2, CO2) concentrations inside MAP relies on the product respiration and the mass transfer through packaging and will affect the quality. The objective of this work is to build a mathematical model for strawberries to assess the effect of the uncertainties on headspace gas concentration and quality: 1) cold chain related temperature and relative humidity variations and 2) variability associated to product respiration and quality based on literature. Weight loss was more influenced by the cold chain storage conditions (temperature and RH) whereas spoilage had similar influence of cold chain conditions and product parameters. Waste generated in the cold chain was estimated from industrial standard weight loss and spoilage thresholds. A sensitivity analysis of the stochastic MAP model showed the influence of input parameters on the quality pointing to interventions associated to a reduction of the respiration rate (e.g. modification of packaging) and reduction of water transfer (e.g. coating) may prove more successful than other interventions to which the waste generation of this product is not so sensitive to. As a conclusion this work presents a toolbox to interpret cold chain data: 1) develop mathematical models to predict fate of quality 2) simulate cold chain conditions allowing for uncertainty 3) estimate the waste generation kinetics based in quality criteria and thresholds 4) perform a sensitivity analysis to identify most sensitive technological parameters 5) identify interventions that will affect those technological parameters. Keywords: Mathematical modelling; Coating; Variability; Sensitivity analysis; Strawberr

Robotics in meat processing

Scientists are currently investigating micro-robotics in the medical field with a potential to provide better medical technology in the near future. When it comes to the food industry, the use of robots has been traditionally limited to picking and palletization. Today, however, robots are used in material handling and secondary or tertiary packing. Recent developments with faster computers and sophisticated sensors have made it possible to use robotics in the meat processing sectors, where their application has reduced processing costs, occupational injuries, improved efficiency and hygiene associated with meat products. Compared to other industries, the working environment in the meat industry is not very conducive to robotics due to the noisy, damp and cold conditions. Slaughtering animals and cutting meat into pieces and disposing waste is an intensive physically demanding task. This chapter reviews the application of robotics in the meat industry and the advancements that have been made until now

Sodium Caprate Enables the Blood Pressure-Lowering Effect of Ile- Pro-Pro and Leu-Lys-Pro in Spontaneously Hypertensive Rats by Indirectly Overcoming PepT1 Inhibition

The tripeptides, Ile-Pro-Pro (IPP) and Leu-Lys-Pro (LKP), inhibit angiotensin-converting enzyme (ACE) resulting in lowered blood pressure. Our hypothesis was that the medium chain fatty acid permeation enhancer, sodium caprate (C10), may prevent the decrease in permeability of the tripeptides when PepT1 is inhibited by glycyl-sarcosine (Gly-Sar), a situation that may occur in the presence of food hydrolysates. Using Caco-2 monolayers and isolated rat jejunal tissue, the apparent permeability coefficients (Papp) of [3H]-IPP and [3H]- LKP were assessed in the presence of Gly-Sar with and without C10. Gly-Sar decreased the Papp of both tripeptides across monolayers and isolated jejunal tissue, but C10 restored it. C10 likely increased the paracellular permeability of the tripeptides, as indicated by immunofluorescence changes in tight junction proteins in Caco-2 monolayers accompanied by a concentration-dependent decrease in transepithelial electrical resistance (TEER). [3H]- IPP and [3H]-LKP were orally-gavaged to normal rats with Gly-Sar, C10, or with a mixture. Plasma levels of both peptides were reduced by Gly-Sar to less than half that of the levels detected in its absence, but were restored when C10 was co-administered. In spontaneously hypertensive rats (SHRs), unlabelled IPP and LKP lowered blood pressure when delivered either by i.v. or oral routes. Oral gavage of Gly-Sar reduced the hypotensive action of peptides in SHRs, but the effect was restored in the presence of C10. In conclusion, there was a reduction in the hypotensive effects of IPP and LKP in SHRs when intestinal PepT1 was inhibited by Gly-Sar, but C10 may circumvent this by enhancing paracellular permeability

Assessing the Effect of Product Variability on the Management of the Quality of Mushrooms (Agaricus bisporus)

To study the shelf-life of mushrooms, over 25 batches were subjected to three storage temperatures (T) (5, 15 and 25 ◦ C) and three storage relative humidity (RH) levels (70, 80 and 90%). The effect of T and the RH on the kinetics of quality attributes of the batches was studied by measuring water activity, turgor, colour (L, a* and b* in the Hunter Scale) and weight loss of three different tissues (cap, gills and stipe) of the mushroom. Linear mixed effect models, comprising polynomial models to describe quality kinetics and allowing for batch-to-batch and inside-batch nested variabilitystructure, were built. The resulting models described changes in the six quality factors with time, their kinetic dependence on temperature and relative humidity and estimated the variability components in a typical retailer situation. Significant quadratic effects, pointing to optimal storage conditions were found for the temperature (L and a values, b value, water activity, turgor and weight) and for the relative humidity (L and a values, b value, water activity and total weight). Optimal storage conditions point to a practice of low temperature and high relative humidity to preserve product weight, although other properties can be optimally preserved using higher storage temperatures and therefore pointing to possible cost savings in storage. Significant batch-to-batch and inside-batch variability components were identified, giving an estimate of the variability expected on the management of different quality attributes of such a biological product in an agricultural retail scenario

Extraction, Quantification, Characterization, and Application in Food Packaging of Chitin and Chitosan from Mushrooms: A Review

The application of chitin in food systems is limited by its insolubility in some common solvents and poor degradability. Hence, it is deacetylated to obtain chitosan, an industrially important derivative with excellent biological properties. Fungal-sourced chitosan is gaining prominence and industrial attraction because of its superior functional and biological properties, and vegan appeal. Further, the absence of such compounds as tropomyosin, myosin light chain, and arginine kinase, which are known to trigger allergic reactions, gives it an edge over marine-sourced chitosan in food and pharmaceutical applications. Mushrooms are macro-fungi with a significant content of chitin, with many authors reporting the highest content to be in the mushroom stalks. This indicates a great potential for the valorisation of a hitherto waste product. Hence, this review was written to provide a global summary of literature reports on the extraction and yield of chitin and chitosan from different fruiting parts of some species of mushrooms, different methods used to quantify extracted chitin, as well as physicochemical properties of chitin and chitosan from some mushroom species are presented. Critical comparisons of reports on chitin and chitosan from mushrooms and other sources are made. This report concludes with an exposition of the potential application of mushroom-sourced chitosan for food packaging application. The reports from this review provide a very positive outlook regarding the use of mushrooms as a sustainable source of chitin and chitosan and the subsequent application of chitosan as a functional component in food packaging

Inactivation of Escherichia Coli in Orange Juice Using Ozone

This research investigated the efficacy of gaseous ozone for the inactivation of Escherichia coli ATCC 25922 and NCTC 12900 strains in orange juice. Orange juice inoculated with E. coli (106 CFU mL-1) as a challenge microorganism was treated with ozone at 75-78µg mL-1 for different time periods (0-18 min). The efficacy of ozone for inactivation of both strains of E. coli was evaluated as a function of different juice types: model orange juice, fresh unfiltered juice, juice without pulp, and juice filtered through 500mm or 1mm sieves. Fast inactivation rates for total reduction of E. coli were achieved in model orange juice (60 seconds) and in juice with low pulp content (6 min). However, in unfiltered juice inactivation was achieved after 15-18 min. This indicated that juice organic matter interferes with antibacterial activity of gaseous ozone. The effect of prior acid (pH 5.0) exposure of E. coli strains on the inactivation efficacy of ozone treatment was also investigated. There was a strain effect observed, where prior acid exposure resulted in higher inactivation times in some cases by comparison with the control cells. However, the overarching influence on inactivation efficacy of ozone was related to the pulp content. Generally, the applied gaseous ozone treatment of orange juice resulted in a population reduction of 5 log cycles

Formulation, characterisation and stability assessment of a food derived 1 tripeptide, Leucine-Lysine-Proline loaded chitosan nanoparticles

The chicken or fish derived tripeptide, Leucine-Lysine-Proline (LKP), inhibits the Angiotensin Converting Enzyme and may be used as an alternative treatment for pre-hypertension. However, it has low permeation across the small intestine. The formulation of LKP into a nanoparticle (NP) has the potential to address this issue. LKP-loaded NPs were produced using an ionotropic gelation technique, using chitosan (CL113). Following optimisation of unloaded NPs, a mixture amount design was constructed using variable concentration of CL113 and tripolyphosphate at a fixed LKP concentration. Resultant particle sizes ranged from 120-271 nm, zeta potential values from 29-37 mV and polydispersity values from 0.3-0.6. A ratio of 6:1 (CL113: TPP) produced the best encapsulation of approximately 65%. Accelerated studies of the loaded nanoparticles indicated stability under normal storage conditions (room temperature). Cytotoxicity assessment showed no significant loss of cell viability and in vitro release studies indicated an initial burst followed by a slower and sustained release