Characterisation of milk samples with various whey protein contents by pyrolysis–mass spectrometry (Py–MS)

Different milk samples and their 2, 5 and 10% mixtures with ‘artificial’ or natural whey protein were analysed by means of pyrolysis–mass spectrometry (Py–MS). Py–MS followed by multivariate analysis of the resulting mass spectra enabled the determination of the whey protein addition in milk samples. Obtained results showed that this determination seems not to be influenced by the fat content and freezing of the samples, as well as a dilution of the samples. ©     

Predictive modelling of the exposure to steviol glycosides in Irish patients aged 1-3 years with phenylketonuria and cow’s milk protein allergy

Children with Phenylketonuria (PKU) and severe cow’s milk protein allergy (CMPA) consume prescribed, specially formulated, foods for special medical purposes (FSMPs) as well as restricted amounts of normal foods. These patients are exposed to artificial sweeteners from the consumption of a combination of free and prescribed foods. Young patients with PKU and CMPA have a higher risk of exceeding acceptable daily intakes (ADI) for additives than age-matched healthy children. A predictive modelling approach has been adapted successfully to assess the additive exposure of young patients with PKU and CMPA to artificial sweeteners. Steviol glycosides (E960) are at various stages of regulatory approval for the various food categories in the EU but are not as yet permitted for use in products intended for young children. The aim of this study was to predict potential steviol glycoside exposure in young children with PKU and CMPA considering the potential for future provisions for the use of this sweetener. The recent introduction of steviol glycosides means that no exposure data are available for children with CMPA and PKU. Food consumption data were derived from the food consumption survey data of healthy young children in Ireland from the National Preschool and Nutrition Survey (NPNS, 2010–11). Specially formulated amino acid-based FSMPs are used to replace whole or milk protein foods and were included in the exposure model to replace restricted foods. The recommendations to ensure adequate protein intake in these patients were used to determine FSMP intake. Exposure assessment results indicated that the maximum permitted level (MPL) for FSMPs would warrant careful consideration to avoid exposures above the ADI. These data can be used to inform recommendations for the medical nutrition industry.     

Effect of liquid whey protein concentrate–based edible coating enriched with cinnamon carbon dioxide extract on the quality and shelf life of Eastern European curd cheese

Fresh unripened curd cheese has long been a well-known Eastern European artisanal dairy product; however, due to possible cross-contamination from manual production steps, high moisture content (50–60%), and metabolic activity of present lactic acid bacteria, the shelf life of curd cheese is short (10–20 d). Therefore, the aim of this study was to improve the shelf life of Eastern European acid-curd cheese by applying an antimicrobial protein-based (5%, wt/wt) edible coating. The bioactive edible coating was produced from liquid whey protein concentrate (a cheese production byproduct) and fortified with 0.3% (wt/wt, solution basis) Chinese cinnamon bark (Cinnamomum cassia) CO₂ extract. The effect of coating on the cheese was evaluated within package-free (group 1) and additionally vacuum packaged (group 2) conditions to represent types of cheeses sold by small and big scale manufacturers. The cheese samples were examined over 31 d of storage for changes of microbiological (total bacterial count, lactic acid bacteria, yeasts and molds, coliforms, enterobacteria, Staphylococcus spp.), physicochemical (pH, lactic acid, protein, fat, moisture, color change, rheological, and sensory properties). The controlled experiment revealed that in group 1, applied coating affected appearance and color by preserving moisture and decreasing growth of yeasts and molds during prolonged package-free cheese storage. In group 2, coating did not affect moisture, color, or texture, but had a strong antimicrobial effect, decreasing the counts of yeasts and molds by 0.79 to 1.55 log cfu/g during 31 d of storage. In both groups, coating had no effect on pH, lactic acid, protein, and fat contents. Evaluated sensory properties (appearance, odor, taste, texture, and overall acceptability) of all samples were similar, indicating no effect of the coating on the flavor of curd cheese. The edible coating based on liquid whey protein concentrate with the incorporation of cinnamon extract was demonstrated to efficiently extend the shelf life of perishable fresh curd cheese, enhance its functional value, and contribute to a more sustainable production process.     

Aspects of transition cow metabolomics—Part I: Effects of a metaphylactic butaphosphan and cyanocobalamin treatment on the metabolome in liver,blood, and urine in cows with different liver metabotypes

Dairy cows in modern production systems are at risk to develop metabolic disorders during the transition period. Reasons for individual differences in susceptibility, as well as the underlying pathomechanisms, are still only partially understood. The development of metaphylactic treatment protocols is needed. In this context, an on-farm prospective 3-fold blinded randomized study involving 80 German Holstein cows was performed throughout 1 yr. The trial involved a thorough recording of the production and clinical traits, clinical chemistry, and liver biopsies and blood and urine sampling at d 14 (mean: 12 d, range: 1–26 d) antepartum (AP), and d 7 (7, 4–13) and 28 (28, 23–34) postpartum (PP) for metabolomics analyses. Two groups received a treatment with butaphosphan and cyanocobalamin (BCC) at either the dosage recommended by the manufacturer or the double dosage (5 or 10 mL/100 kg of body weight 10% butaphosphan and 0.005% cyanocobalamin (Catosal, Bayer Animal Health), n = 20 in each group, parity: 4.2 ± 2.0 and 3.4 ± 1.3, respectively (mean ± SD)] and one group a placebo treatment (NaCl 0.9%, n = 40, parity: 4.0 ± 1.9). The animals were treated at 6 time points (7, 6, and 5 d AP, and 1, 2, and 3 d PP) via intravenous injection. Mass spectroscopy-based targeted metabolomics analysis of blood plasma and liver samples were performed using the AbsoluteIDQ p180 kit (Biocrates Life Sciences), whereas the urine samples were analyzed by nuclear magnetic resonance spectroscopy. Statistical analysis was performed using multivariate [partial least squares discriminant analysis (PLS-DA)] and univariate methods (linear mixed model). Multivariate data analysis (PLS-DA plots) of the liver metabolome revealed 3 different metabotypes (A = medium, B = minor, C = large alterations in liver metabolome profile between AP and PP status). Metabotype B animals were characterized by higher PP lipomobilization (stronger PP body condition decrease and higher blood bilirubin, fatty acids, gamma-glutamyltransferase, and triglyceride levels) and a higher occurrence of transition cow diseases, compared with the animals in metabotype C. Analysis of the feeding data showed that the period of metabotype B animals (calving in a distinct time frame) was characterized by a decreased grass silage quality. The PP liver metabolome of the metabotype C animals was characterized by higher concentrations of AA, acylcarnitines, lysoPC and sphingomyelins compared with metabotype B. For the metaphylactic treatment with BCC a dose-dependent effect was confirmed, differing between the metabotypes. In all matrices and metabotypes at various time points significant treatment effects were observed, with different profiles in clinical chemistry and as well in metabolomics data. The most clear-cut treatment effect was observed in metabotype B in the liver at 7 d PP, characterized by an increase in several acylcarnitines and phosphatidylcholines, indicating a more efficient influx and oxidation of fatty acids in mitochondria and thereby an increase in energy supply and more efficient triglyceride export in the liver. The results from the liver metabolomics analysis support the application of an indication-based metaphylactic treatment with BCC.