Sensory evaluation of precooked chicken meat with mate (<Emphasis Type="Italic">Ilex paraguariensis</Emphasis>) added as antioxidant

Dried mate leaves or aqueous extract of dried mate leaves added to chicken meat balls prior to cooking for antioxidant protection was found not to affect taste or smell of the product significantly for addition corresponding to 0.050% of dried mate leaves, while 0.10% changed the smell but not the taste and more significantly for dried leaves. Addition of aqueous mate extract corresponding to 0.050% of mate is recommended as an alternative to more strongly flavoured herbs for oxidative protection of meat products.     

A standardized conjugation protocol to asses antibiotic resistance transfer between lactococcal species

Optimal conditions and a standardized method for conjugation between two model lactococcal strains, Lactococcus lactis SH4174 (pAMbeta1-containing, erythromycin resistant donor) and L. lactis Bu2-60 (plasmid-free, erythromycin sensitive recipient), were developed and tested in a inter-laboratory experiments involving five laboratories from different countries. The ultimate goal of the study was to assess the microbial potential of antibiotic resistance transfer among Lactic Acid Bacteria (LAB). The influence of culture age (various OD values) and ratios of donor and recipient cultures as well as filter, solid and liquid mating techniques, were examined in order to optimize the conjugation protocol. In the result of these studies, we concluded that the donor-to-recipient ratio appear to be important; the most efficient technique for conjugation was filter mating and the optimal conditions for gene transfer were observed when late logarithmic cultures of both donor and recipient were used. Comparison of conjugal transfer frequencies between five partner laboratories showed that results are sufficiently intra-laboratory repeatable and inter-laboratory comparable. This is the first study of this kind, in which a standardized protocol of conjugal mating for testing antibiotic resistance dissemination among LAB was established and validated.     

Sensory profiles of breast meat from broilers reared in an organic niche production system and conventional standard broilers

BACKGROUND: Breast meat from broilers produced in very different production systems may vary considerable in sensory profile, which may affect consumer interests. In this study the aim was to evaluate differences in the sensory profiles of breast meat from five broiler products: two conventional standard products (A and B) and three organic niche genotypes (I657, L40 and K8) reared in an apple orchard. RESULTS: Thirteen out of 22 sensory attributes differed significantly between the products. The aroma attributes ‘chicken’, ‘bouillon’ and ‘fat’ scored highest and the ‘iron/liver’ aroma lowest for the niche products. The meat was more ‘tender’, ‘short’ and ‘crumbly’ and less ‘hard’ and ‘stringy’ in the standard products than in one or more of the niche products. Product ‘I 657’ was less ‘juicy’ than the rest. Products ‘I 657’ and ‘L 40’ were more ‘cohesive’ and tasted more ‘sourish’ and less of ‘sweet/maize’ than the standard products. The ‘overall liking’ score was significantly higher for the ‘K 8’ product than for the ‘Standard A’ and ‘L 40’ products. The ‘overall liking’ score was significantly correlated with the scores for aroma and taste of ‘chicken’, ‘umami/bouillon’, ‘iron/liver’ and ‘fat’ aroma. CONCLUSION: The sensory profiles differed particularly between conventional standard broilers and organic niche broilers, although differences were also found between breeds. The present study indicates that aroma and taste attributes were more important for the assessors than meat ‘tenderness’ for the overall liking of broiler meat. Copyright © 2011 Society of Chemical Industry     

Polymer flocculation mechanism in animal slurry established by charge neutralization

Flocculation and filtration of animal manure is practically and environmentally beneficial. However, the flocculation mechanism in manure need to be clarified to use the technique efficiently rather than relying on trial-and-error. Manures were flocculated with polyacrylamides. Floc size, dewaterability, dry matter and turbidity were measured. At optimal polymer volume, the charge neutralization was determined, i.e. amount of negative manure particle charge neutralized by positive polymer charge. The optimal cationic polymer properties were linear and very high molecular weight, which caused efficient particle catching. And it had medium charge density, which caused efficient particle attachment. The required charge neutralization was 5-23% (15% for the optimal polymer). Polymer bridging proved the dominant flocculation mechanism; patch flocculation may be slightly significant for some polymers, while coagulation proved insignificant. Manure’s high ionic strength, high dry matter content and highly charged small molecules caused bridging to be more dominant in manure than in other typically flocculated media.     

Free-standing silicon-nitride zoneplates for neutral-helium microscopy

The ground-state helium-4 beam employed by the microscopy technique discussed in this article interacts exclusively with the atoms in the topmost sample-monolayer. Its low-energy (tens of meV) and chemical inertness make the beam an almost ‘ideal’ imaging probe in the sense that a sample surface can be imaged without alteration by the probe. The microscopy technique therefore has promising applications in the imaging of fragile samples and metrology. In this article we present a fabrication process for the diffraction-based focusing element (Fresnel Zoneplate) in such a setup. Zoneplates made previously for this purpose have suffered from low transmission, a problem we have solved with our new process. In addition, we have measured the first-order diffraction efficiency of three zoneplates fabricated with this process. The efficiency of a zoneplate with 388 μm diameter was close to 70% of the theoretically predicted value. We believe the reduction stems mainly from misalignment between the writefields used to pattern the zoneplate. The fabricated zoneplates of 190 μm diameter, which we patterned using a single writefield, have close to the theoretically predicted transmission characteristics; a result that has not been achieved before for neutral atom Fresnel lenses.     

A procedure for identifying textile bast fibres using microscopy: Flax,nettle/ramie,hemp and jute

Identifying and distinguishing between natural textile fibres is an important task in both archaeology and criminology. Wool, silk and cotton fibres can readily be distinguished from the textile bast fibres flax, nettle/ramie, hemp and jute. Distinguishing between the bast fibres is, however, not easily done and methods based on surface characteristics, chemical composition and cross section size and shape are not conclusive. A conclusive method based on X-ray microdiffraction exists, but as the method requires the use of a synchrotron it is not readily available. In this paper we present a simple procedure for identifying the above mentioned textile bast fibres. The procedure is based on measuring the fibrillar orientation with polarised light microscopy and detecting the presence of calcium oxalate crystals (CaC₂O₄) in association with the fibres. To demonstrate the procedure, a series of fibre samples of flax, nettle, ramie, hemp and jute were investigated. The results are presented here. An advantage of the procedure is that only a small amount of fibre material is needed.     

Effect of grass–clover forage and whole‐wheat feeding on the sensory quality of eggs

BACKGROUND: A sensory panel evaluated the sensory profile of eggs from hens from three experimental systems: (1) an indoor system × normal layer diet (InL), (2) a grass–clover forage system × normal layer diet (GrL), and (3) a grass–clover forage system × whole wheat and oyster shells (GrW). RESULTS: The taste of the albumen was significantly more ‘watery’ and the yolks a darker yellow/orange in the eggs from the GrL and GrW groups. The yolk was darkest from the GrW group. The yolks from the InL and GrW groups had a significantly more ‘fresh’, less ‘animal’, ‘cardboard’, and ‘intense’ aroma than the GrL group. The taste of the yolks from the InL and GrW groups was significantly more ‘fresh’ and less ‘cardboard’‐like compared to the GrL group. The yolks tasted significantly less ‘sulfurous’ in the GrW group than in the GrL group. CONCLUSION: The combination of a high feed intake from a grass–clover pasture and the type of feed allocated is an important factor in relation to the sensory quality of eggs. Thus, a less favourable sensory profile of eggs was found from hens on a grass–clover pasture and fed a normal layer diet. Copyright © 2009 Society of Chemical Industry