Performance of current microbial tests for screening antibiotics in sheep and goat milk

[EN] The detection capability (CC beta) of some microbial screening tests currently available was calculated for sheep and goat milk in accordance with Commission Decision 657/2002/EC. The CC beta was at or below the maximum residue limit (MRL) for most beta-lactams assessed and other non-beta-lactam drugs such as neomycin, tylosin, sulfadiazine and sulfadimethoxine. However, the tests were less sensitive in the detection of most non-beta-lactam drugs such as quinolones and tetracyclines at safety levels. When individual sheep milk samples free of antibiotics were analysed, an elevated somatic cell count was related to the occurrence of non-compliant results in all the methods assessed. To guarantee the safety of milk and dairy products from small ruminants, the periodical implementation of screening tests more sensitive towards non-beta-lactam drugs would be appropriate. (C) 2014 Elsevier Ltd. All rights reserved.This research forms part of the Project AGL2009-11524 financed by the Ministerio de Ciencia e Innovacion (Madrid, Spain).Beltrán Martínez, MC.; Berruga Fernandez, MI.; Molina Casanova, A.; Lisandro Althaus, R.; Molina Pons, MP. (2015). Performance of current microbial tests for screening antibiotics in sheep and goat milk. International Dairy Journal. 41:13-15. https://doi.org/10.1016/j.idairyj.2014.09.007S13154

Prediction of Zamorano cheese quality by near-infrared spectroscopy assessing false non-compliance and false compliance at minimum permitted limits stated by designation of origin regulations

Near-infrared transmittance (NIT) spectroscopy was used to predict the percentage in weight of the fat, dry matter, protein and fat/dry matter contents in Zamorano cheeses, protected with a Designation of Origin by the European Union. A total of 42 cheeses submitted to official control were analysed by reference methods. Samples were scanned (850–1050 nm) and predictive equations were developed using Partial Least Squares regression with a cross-validation step. Eight pretreatments independent from the remaining calibration samples were first considered. The most adequate one was that performing the second derivative (using a Savitzky–Golay method with a nine-point window and a second-order polynomial) followed by the standard normal variate transformation. Percentages of the root mean square error in cross-validation, the coefficient of determination and the mean of the absolute value of relative errors found were, respectively, for fat (0.62; 96.16; 1.05), dry matter (0.76; 96.03; 0.83), protein (0.41; 97.82; 0.81) and the fat/dry matter ratio (0.61; 92.51; 0.66). At a 99% confidence level, the trueness of the NIT+PLS methods for fat, dry matter and protein was verified. The official regulation for Zamorano cheese demands minimum permitted limits on the percentages in weight for protein (25%), dry matter (55%) and the ratio of fat to dry matter (45%). The adaptation of both the decision limit and the detection capability to the case of a minimum permitted limit (CDα and CDβ, respectively) when a Partial Least Squares calibration is used has been applied for the first time for a food product protected by a Designation of Origin. The values of CDα with a probability of false non-compliance equal to 0.05 and of CDβ when, in addition, the probability of false compliance was equal to or less than 0.05, both provided by the corresponding NIT+PLS-based method, were, respectively, for protein (24.78%; 24.57%), dry matter (54.14%; 53.28%) and the fat/dry matter ratio (44.39%; 43.78%).authorsthankthefinancialsupportprovidedbyMinisterio de CienciaeInnovacio´n (CTQ2011-26022)andJuntadeCastillay Leo´n (BU108A11-2

The value of manure - Manure as co-product in life cycle assessment

Research ArticleLivestock production is important for food security, nutrition, and landscape maintenance, but it is associated with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent and robust indicators are required, such as those offered by life cycle assessment. A central question in such approaches is how environmental burden is allocated to livestock products and to manure that is re-used for agricultural production. To incentivize sustainable use of manure, it should be considered as a co-product as long as it is not disposed of, or wasted, or applied in excess of crop nutrient needs, in which case it should be treated as a waste. This paper proposes a theoretical approach to define nutrient requirements based on nutrient response curves to economic and physical optima and a pragmatic approach based on crop nutrient yield adjusted for nutrient losses to atmosphere and water. Allocation of environmental burden to manure and other livestock products is then based on the nutrient value from manure for crop production using the price of fertilizer nutrients. We illustrate and discuss the proposed method with two case studiesinfo:eu-repo/semantics/publishedVersio

Analysis of the water‐soluble compounds as a tool for discriminating traditional and industrial high moisture mozzarella made with citric acid

High moisture mozzarella from cow milk is a pasta filata cheese that can be manufactured by different protocols. Fermentation by autochthonous starter is used for the traditional product, whereas direct acidification with citric acid is widely used at industrial level. Both types are stored immersed in a liquid for preserving freshness, but this packaging method is known to favour the changes of the quality characteristics. The present study aimed to assess the evolution of the soluble compounds and to evaluate their use as chemical indices for discriminating the two types of mozzarella. The contents of lactose, organic acids, water soluble nitrogen and free aminoacids differently changed over time. The whole patterns of these soluble compounds allowed discrimination of the two products during the whole storage period. The simple analyses of lactic acid and lactose could be a rapid tool to protect traditional mozzarella from industrial imitations obtained with citric acid

Validation of a reversed‐phase high‐performance liquid chromatographic method for the quantification of primary proteolysis during cheese maturation

peer-reviewedA new fast and reliable reversed-phase high-performance liquid chromatographic method is proposed for quantifying all the major casein fractions during cheese proteolysis as an alternative to more complex methodologies. Excellent separation of the caseins, para-κ-casein (ρ-κ-CN), αs1-casein (αs1-CN), αs1-I-casein (αs1-I-CN), αs2-casein (αs2-CN), and β-casein (β-CN) was achieved, in terms of linearity, reproducibility, repeatability, accuracy and certified standard recovery. Validation by quantification of semihard and Maasdam-style cheeses gave comparable results for ρ-κ-CN, β-CN and αs-casein (αs-CN) to published data for both urea–polyacrylamide gel electrophoresis and capillary electrophoresis