Cherry (Prunus cerasus cv Montmorency) extract with standardised antioxidant potential as preservative for refrigerated storage of ground pork

Antioxidants occurring naturally are much sought‐after for their safety of use for human nutrition and strong preservative properties. The study was performed to determine the antioxidant potential of sour cherry extract and its effect (equivalent of 20 mg and 40 mg GAE kg^?1) on the quality of ground pork patties during 8‐day storage. The patties were analysed for antioxidant capacity, oxidation, profile of fatty acids, flavour, colour, sensory properties and aerobic bacteria count. Patties with addition of cherry extract (40 mg GAE kg^?1) showed higher antioxidant capacity of 844 ± 149 μmol TE L^‐1 on the last day of the storage than the control group where the result was 480 ± 81 μmol TE L^‐1. The addition of extract caused lower overall increase in lipid oxidation and prevented loss of redness even on the last day of the storage. Flavour changes resulted from oxidation and decrease in the amount of desirable volatile compounds in storage. The application of the extract from Prunus cerasus combined with vacuum packaging inhibited both oxidation and quality deterioration of pork patties in cold storage.     

Characterisation of composite edible films based on wheat starch and whey‐protein isolate

Composite films prepared by casting wheat starch and whey‐protein isolate at proportions of 100–0%, 75–25%, 50–50%, 25–75% and 0–100% were characterised. Combination of both substances gave continuous and homogeneous films. The more the starch is in a film, the more dull is the appearance. The highest water adsorption was observed for pure whey‐protein films and the lowest for pure wheat starch films with the final water content of 0.264 and 0.324 g water g d.m.^?1, respectively. An exponential equation well fitted the experimental data of water vapour kinetics (R² ≥ 0.99). The highest values of thickness and elongation at break were observed for films obtained by blending of wheat starch and whey protein. With the increasing content of whey‐protein isolate, the values of the swelling index and tensile strength increased from 34.31% to 71.01% and from 2.29 to 8.90 MPa, respectively. The values of water vapour permeability depended on humidity conditions and decreased slightly with the increasing content of whey‐protein isolate.     

Assessment of aliphatic poly(ester-carbonate-urea-urethane)s potential as materials for biomedical application

Selected mechanical and biological properties of biodegradable elastomeric poly(ester-carbonate-urea-urethane)s (PECUUs) point towards their potential to be applied as scaffolds in tissue engineering. Here we explore their medical applicability taking into account their hemocompatibility and cytotoxicity. The influence of the ester monomer (derivatives of adipic and succinic acids), as well as diisocyanate type (IPDI and HDI) on the investigated PECUUs properties is presented. The presence of aliphatic diisocyanates, cyclic IPDI or linear HDI, governs the adhesion of Candida cells to these polymers offering the possibility to control the biofilm formation on their surface. In comparison to the linear form, cyclic diisocyanates with pentamethylene succinate or adipate fragments had two to three times lower biofilm mass formation on their surface. Reduced hemoglobin release from red blood cells observed during incubation of tested polymers with human erythrocytes suspension indicates their potential biocompatibility with human tissues. PECUUs were also able to support the growth of human keratinocytes HaCaT on their surface when coated with collagen. In effect, IPDI derivatives might possess a high potential for use in biomedical applications.     

Characterisation of antioxidant compounds in sweet bell pepper (Capsicum annuum L.) under organic and conventional growing systems

BACKGROUND: Sweet red bell pepper is one of the best sources of ascorbic acid and carotenoids as well as phenolic compounds important in the human diet. There have been some studies showing a higher level of bioactive compounds in organic bell pepper fruits compared with conventional fruits, but not all studies have been consistent in this respect. The levels of carotenoids and phenolics are very variable and may be affected by ripeness, genotype and cultivation. RESULTS: The results obtained in this study showed that an organic growing system affected the level of bioactive compounds (carotenoids and polyphenols) in sweet bell pepper fruits cultivated in Poland. Organic bell pepper fruits contained significantly more dry matter, vitamin C, total carotenoids, β‐carotene, α‐carotene, cis‐β‐carotene, total phenolic acids (as well as individual gallic and chlorogenic acids) and flavonoids (quercetin D ‐glucoside, quercetin and kaempferol) compared with conventional fruits. The bell pepper variety also affected the level of antioxidant compounds in fruits. CONCLUSION: Organic growing increased the level of antioxidant compounds such as carotenoids, phenolic compounds and vitamin C in sweet bell pepper. The second significant factor affecting the antioxidant compound content of sweet bell pepper was variety. It would be necessary to continue this study as a long‐term experiment in order to eliminate the influence of seasonality. Copyright © 2012 Society of Chemical Industry     

Comparison of quality and microstructure of chokeberry powders prepared by different drying methods,including innovative fluidised bed jet milling and drying

Food Science and Biotechnology - The study assessed the functional properties, microstructural features and sensory characteristics of chokeberry powders obtained by the new fluidised bed jet...     

Feeding strategy impacts heterologous protein production in Yarrowia lipolytica fed-batch cultures—Insight into the role of osmolarity

Fed-batch cultivation is the preferred bioprocessing strategy applied in microbial production of proteins. Feeding strategy is crucial parameters to be optimized upon development of a fed-batch process. In this study, we investigated impact of different feeding strategies on production of recombinant enzymatic protein in Yarrowia lipolytica cultures. From amongst tested strategies, comprising intermittent and continuous feedings, also in cascade with respiratory factors, intermittent feeding executed after complete exhaustion of glycerol from the medium, with moderate amplitude of osmolarity, was the most beneficial in terms of the secretory enzyme amount, its volumetric productivity and specific activity. Because adopted feeding strategies strongly modulated osmolarity of the cultures, the effect of osmotic pressure on production of the target heterologous protein was investigated in a series of batch cultivations with addition of osmoactive compounds (NaCl, sorbitol, sucrose, and glycerol) at different concentrations. Although obvious promoting effect of the osmoactive substances on the enzyme production was clear, no straightforward correlation between the medium osmolarity and the target enzyme's specific activity could be observed. These results suggest that not only the level of osmolarity but also chemical character of the osmoactive compound have both important impact on the production of secretory proteins in Y. lipolytica cultures.     

Symposium review: Genomic investigations of flavor formation by dairy microbiota

Flavor is one of the most important attributes of any fermented dairy product. Dairy consumers are known to be willing to experiment with different flavors; thus, many companies producing fermented dairy products have looked at culture manipulation as a tool for flavor diversification. The development of flavor is a complex process, originating from a combination of microbiological, biochemical, and technological aspects. A key driver of flavor is the enzymatic activities of the deliberately inoculated starter cultures, in addition to the environmental or “nonstarter” microbiota. The contribution of microbial metabolism to flavor development in fermented dairy products has been exploited for thousands of years, but the availability of the whole genome sequences of the bacteria and yeasts involved in the fermentation process and the possibilities now offered by next-generation sequencing and downstream “omics” technologies is stimulating a more knowledge-based approach to the selection of desirable cultures for flavor development. By linking genomic traits to phenotypic outputs, it is now possible to mine the metabolic diversity of starter cultures, analyze the metabolic routes to flavor compound formation, identify those strains with flavor-forming potential, and select them for possible commercial application. This approach also allows for the identification of species and strains not previously considered as potential flavor-formers, the blending of strains with complementary metabolic pathways, and the potential improvement of key technological characteristics in existing strains, strains that are at the core of the dairy industry. An in-depth knowledge of the metabolic pathways of individual strains and their interactions in mixed culture fermentations can allow starter blends to be custom-made to suit industry needs. Applying this knowledge to starter culture research programs is enabling research and development scientists to develop superior starters, expand flavor profiles, and potentially develop new products for future market expansion.     

Simultaneous analysis of coccidiostats and sulphonamides in non-target feed by HPLC-MS/MS and validation following the Commission Decision 2002/657/EC

Taking into consideration the maximum level (ML) for coccidiostats included in the European Regulation 574/2011 and the fact that the presence of residues of sulphonamides in non-target feed is forbidden, the aim of this article is to present an analytical method based on HPLC-MS/MS for the identification and quantification of sulphonamides and coccidiostats in non-target feeds. The method was validated following Commission Decision 2002/657/EC, and recovery, repeatability and reproducibility were within the limits established in the Decision. For coccidiostats, the decision limit and detection capability were calculated for the different species taking into account the ML allowed in Regulation 574/2011. The applicability of the method was investigated in 50 feed samples collected from dairy farms, 50 obtained from feed mills and 10 interlaboratory feed samples.     

Digestion and bioavailability of bioactive phytochemicals

There are many scientific reports on determination of the content and biological activity of compounds found in food. However, these analyses are not sufficient to determine their effect on the human body. During digestion of food ingredients, many changes can modify their structure and this may affect their absorption and bioactivity. Many phenolic aglycones are hydrophilic and can be absorbed through biological membranes by diffusion. However, most polyphenols occur in the glycosidic form, which undoubtedly affects their absorption in the intestine. Oligopeptides are also absorbable via secondary active transport but based on the hydrogen ion gradient or with transporter PepT1. The bioavailability of phytochemicals is determined by their molecular weight or chemical structure and the food matrix. Accordingly, the aim of this work was to present the novel scientific reports related to the influence the many factors on digestibility, bioaccessibility and activity of selected bioactive compounds of plant origin.