Temperature-dependent Henry's Law constants of 4-alkyl branched-chain fatty acids and 3-methylindole in an oil-air matrix and analysis of volatiles in lamb fat using selected ion flow tube mass spectrometry

Valuation of Goat and Sheep By-Products: Challenges and Opportunities for Their Use

Goat and sheep meat production is a challenge for the meat industry as well as for environmental management. Yet within cultures, certain by-products, such as liver, the lungs, heart, brain, spleen, blood, tail and ears, are traditionally used in the production of typical dishes for regional or local cuisine. These by-products are a rich source of lipids, proteins, essential amino acids, B-complex vitamins, and minerals. They can be effectively exploited for higher (value-added) applications, including functional foods or feed ingredients, food supplements, enzymes and other chemical products such as hydrolyzed proteins and flavorings. This review article gathers data on: (i) the production of by-products obtained from slaughter and available for processing, and (ii) potential strategies for using and applying these by-products in obtaining new value-added ingredients. Other than proteins, the review discusses other macromolecules and possible uses of these by-products in culinary dishes, as hydrolyzed enzymes, and as food additives. Even though these by-products undoubtedly present themselves as rich in nutrients, there remains an unfortunate lack of documented information on the potential use of these by-products for their bioactive components, peptides that have various biological and technological properties, and the use of hydrolyzed versions of these by-products as precursors for the production of flavorings.

The effects of age, sex, and hot carcass weight on cooked lamb flavor and off-flavor in four muscle cuts

The present study used 48 lambs originating from three different locations in the Western United States (16 lambs per location; 8 ewes and 8 wethers per location). Each consisting of similar breed composition (Suffolk cross) that were selected to represent weight by age at harvest treatments: light weight carcasses at 5 mo (LW5, 31.81 ± 1.88 kg), light weight carcasses at 12 mo (LW12, 35.09 ± 4.45 kg), heavy weight carcasses at 12 mo (HW12, 57.89 ± 4.70 kg) with different carcass weight compositions. Older heavy weight lambs (HW12) had greater (P ≤ 0.01) hot carcass weight, ribeye area, backfat and body wall thickness, and yield grade compared with light weight lamb carcasses (LW5 and LW12). The longissimus thoracis longissimus thoracis (LT) from older lamb carcasses (LW12 and HW12) had a greater (P ≤ 0.01) total lipid percentage compared with younger lamb carcasses (LW5). Across harvest weight and age treatments, wether carcasses had greater (P ≤ 0.05) total lipid percentage compared with ewe carcasses. Slice shear force values were greater (P ≤ 0.01) for both the LT and semimembranosus from older lambs (LW12 and HW12) compared with LW5 lambs, with no differences between ewes and wethers. Lamb flavor intensity was greater (P ≤ 0.05) for the LT of LW12 lambs and tended (P = 0.08) to be greater for HW12 lambs, compared with the LT from LW5 lambs. The off-flavor intensity of the LT was greater (P ≤ 0.01) for older lambs (LW12 and HW12) compared with LW5 lambs. Interestingly, the lamb flavor and off-flavor intensity scores of the ground shoulder exhibited a treatment × sex interaction. Lamb flavor intensity of LW12 lamb was greater (P ≤ 0.05) from ewes compared with wethers, whereas wethers had a greater (P ≤ 0.05) lamb flavor intensity compared with ewes for HW12 lambs, and LW12 ewe lambs had a greater (P ≤ 0.05) off-flavor intensity compared with all other treatment × sex treatment combinations. Overall, lambs in the present study possessed a mild lamb flavor, typically with greater lamb flavor and off-flavor intensities for older animals; while slice shear force and LT lipid percentage increased as animal age increased at the time of harvest.

Cyanogenesis in Macadamia and Direct Analysis of Hydrogen Cyanide in Macadamia Flowers, Leaves, Husks, and Nuts Using Selected Ion Flow Tube-Mass Spectrometry

Macadamia has increasing commercial importance in the food, cosmetics, and pharmaceutical industries. However, the toxic compound hydrogen cyanide (HCN) released from the hydrolysis of cyanogenic compounds in Macadamia causes a safety risk. In this study, optimum conditions for the maximum release of HCN from Macadamia were evaluated. Direct headspace analysis of HCN above Macadamia plant parts (flower, leaves, nuts, and husks) was carried out using selected ion flow tube-mass spectrometry (SIFT-MS). The cyanogenic glycoside dhurrin and total cyanide in the extracts were analyzed using HPLC-MS and UV-vis spectrophotometer, respectively. HCN released in the headspace was at a maximum when Macadamia samples were treated with pH 7 buffer solution and heated at 50 °C for 60 min. Correspondingly, treatment of Macadamia samples under these conditions resulted in 93%-100% removal of dhurrin and 81%-91% removal of total cyanide in the sample extracts. Hydrolysis of cyanogenic glucosides followed a first-order reaction with respect to HCN production where cyanogenesis is principally induced by pH changes initiating enzymatic hydrolysis rather than thermally induced reactions. The effective processing of different Macadamia plant parts is important and beneficial for the safe production and utilization of Macadamia-based products.

The application of selected ion flow tube-mass spectrometry to follow volatile formation in modified-atmosphere-packaged cooked ham

Cooked pork products, i.e., sliced cooked hams maintained under modified-atmosphere-packaging (MAP), were analysed both microbiologically and with respect to volatile levels during storage. Three storage temperature ranges were compared (4-6 °C, 7-9 °C, and 11-13 °C), representing different refrigeration conditions at household level. The microbial loads were determined by plating samples on six different agar media, followed by (GTG)₅-PCR fingerprinting of genomic DNA of selected isolates, and identification of representative isolates by 16S rRNA, pheS, and rpoA gene sequencing. Carnobacterium maltaromaticum, Lactobacillus sakei, and Serratia proteamaculans were the major bacterial species found among the 619 isolates identified. The volatiles produced during storage were followed by selected ion flow tube-mass spectrometry (SIFT-MS) and the identity of the volatiles was confirmed by headspace solid-phase microextraction combined with gas chromatography and time-of-flight mass spectrometry (HS-SPME-GC-TOF-MS). SIFT-MS analysis showed that volatiles, such as 2,3-butanediol, acetoin, and ethanol, may serve as potential markers for spoilage development. Differences in volatile production between samples were likely due to discrepancies in the initial microbial load and the effect of storage conditions. In conclusion, this study combines the use of new mass spectrometric techniques to examine volatile production during spoilage as an additional source of information during microbiological community analysis.