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The composition of garlic (Allium sativum L.) may vary among cultivars and, moreover, change over time, thereby affecting both biological activity and flavour. Thus, it is important to identify the trends in the content of bioactive compounds in garlic, by reliable analytical methods. This study was focused on the key sulfur-containing compounds, S-alk(en)yl-l-cysteine sulfoxides (alliin, isoalliin, methiin, propiin), which were quantified by a fast liquid chromatography – tandem mass spectrometry (LC-MS/MS) method. Several garlic cultivars were monitored repeatedly within seven months: one month before harvest maturity; at harvest maturity; and after two and six months of storage. The results showed not only a high variability among individual cultivars, but also among samples of the same cultivar grown at different localities. During storage, a significant increase in isoalliin content (up to 54-fold after six months) occurred. Nevertheless, none of the cultivars showed significantly different properties compared to others, suggesting that many other factors affect garlic composition. [ABSTRACT FROM AUTHOR]

BACKGROUND: The production and consumption of chicken has doubled in the last 17 years. Since slaughter yields range from 70 to 80%, during production various chicken waste residues are generated. One of these residues is waste created after the mechanical separation of chicken meat (W‐MSM). The goal of the circular economy is to manage this waste and transform it into a valuable product. RESULTS: W‐MSM was subjected to hydrolysis by the proteolytic enzymes pepsin and papain to obtain bioactive compounds. Papain digestion resulted in several times higher yields of chondroitin sulfate (CS), hyaluronic acid (HA), peptides and amino acids in comparison with pepsin. The hydrolysis conditions were further optimized using the software Design Expert to evaluate the impact of added enzyme, buffer and duration of the hydrolysis. In addition, the scale‐up of this process was verified with 5 kg of W‐MSM and the obtained product contained approximately 77% (w/w) of peptides, 9% (w/w) of CS, 7% (w/w) of HA and 4% (w/w) of amino acids. CONCLUSIONS: We tested and optimized the method for evaluating the direct waste from poultry processing and transformed it into a product containing bioactive compounds which can be utilized as an ingredient for improving the properties of feed. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The aim of the study was to develop an efficient method for assessment of meat origin and determination of net muscle protein (NMP; based on amino acids and ß-alanylhistidine dipeptides) in meat products using the ultra-high performance liquid chromatography coupled with mass spectrometry. As an important result, a database of ratios of particular amino acids to 3-metylhistidine, applicable for muscle protein origin confirmation, was established. Based on the specific ratios of 1-methylhisitidine/3-methylhistidine, revealing of undeclared addition of 2% of chicken meat to the pork was enabled. Similar outcome was achieved by considering the ratios of ß-alanylhistidine dipeptides. In the case of chicken-pork and pork-beef admixtures, as low additions as 0.5 and 2% of chicken or pork adulterant could be recognized. The ratio of 4-hydroxyproline/3-methylhisitidine was shown to be diagnostic for detection undeclared addition of 0.5 and 1.5% of connective tissues into the pork and chicken meat, respectively. On the basis of 3-methylhisitidine concentration, the conversion factor F = 292 ± 4 was calculated for quantification of NMP (%) content. [ABSTRACT FROM AUTHOR]

ABSTRACT BACKGROUND Millions of tons of feather waste from the poultry industry are disposed of annually despite containing a high level of keratin. The aim of this study was to compare the hydrolysis of non-treated feather waste using three different approaches (whole cell microbial digestion, enzymatic and chemical cleavage) and to test the use of hydrolysates as peptone substitutes in a culture medium. RESULTS Among bacterial isolates, Pseudomonas sp. P5 exhibited the highest keratinolytic activity and efficiency to hydrolyse raw feather material. The hydrolysates contained up to 301 mg L−1 of free amino acids and 6.2 g L−1 of peptides. Hydrolysates obtained by digestion using semi-purified keratinase from Pseudomonas sp. P5 were richer in amino acids (1191 mg L−1, 56% essential ones) but peptides were present in lower amounts (up to 3.3 g L−1). The third approach was feather treatment under mild alkaline conditions. This provided the highest amount of peptides (17.2 g L−1) but a significantly lower level of amino acids, especially the essential ones. CONCLUSIONS All approaches tested could convert raw feather waste into products of commercial value with proven use in a cultivation medium. The level of peptides, their molecular size and amino acid composition was dependent on the method used. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Two alternative, complementary analytical strategies were successfully used to identify the most common meat species—beef, pork and chicken—in meat products. The first innovative high-throughput approach was based on triacylglycerols fingerprinting by direct analysis in real time coupled with high-resolution mass spectrometry (DART–HRMS). The second was the classic commonly used DNA analysis based on the use of nuclear or mitochondrial DNA in multiplex polymerase chain reaction (mPCR). The DART–HRMS method represents a rapid, high throughput screening method and was shown to have a good potential for the authentication of meat products. Nevertheless, it should be noted that due to a limited number of samples in this pilot study, we present here a proof of concept. More samples must be analyzed by DART–HRMS to build a robust classification model applicable for reliable authentication. To verify the DART–HRMS results, all samples were analyzed by PCRs. Good compliance in samples classification was documented. In routine practice under these conditions, screening based on DART–HRMS could be used for identification of suspect samples, which could be then examined and validated by accurate PCRs. In this way, saving of both labor and cost could be achieved. In the final phase, commercially available meat products from the Czech market were tested using this new strategy. Canned meats—typical Czech sausages and luncheon meats, all with declared content of beef, pork and chicken meat—were used. Compliance with the label declaration was confirmed and no adulteration was found. [ABSTRACT FROM AUTHOR]