Prevalence and relationships of sensory taint, 5α-androstenone and skatole in fat and lean tissue from the loin (Longissimus dorsi) of barrows, gilts, sows, and boars from selected abattoirs in the United States

This study assessed prevalence of boar taint in backfat and lean of barrows, gilts, sows, and boars, collected from abattoirs, without knowledge of the farms of origin, in different regions in the United States. Concentrations of 5α-androstenone (liquid chromatography/mass spectroscopy) and skatole (liquid chromatography with fluorescent detection) in backfat were measured. A trained panel evaluated boar taint aroma in heated samples. Mean 5α-androstenone and skatole levels were low among barrows, gilts, and sows, whereas 55.8% of boars scored above a 1.0 μg/g threshold for 5α-androstenone concentrations and 34.2% were above a 0.2 μg/g threshold for skatole concentrations. Mean aroma scores for backfat and lean from barrows, gilts, and sows were low. In comparison, 59.2% of boars had elevated mean aroma scores from fat samples and 31.7% from lean. Importantly, boar taint aroma was detectable by the trained panel in at least some animals in each of the sex classes.     

Quantitative determination of kokumi compounds, γ-glutamyl peptides,in Korean traditional fermented foods,ganjang and doenjang,by LC-MS/MS

Food Science and Biotechnology - Recent studies have shown that γ-glutamyl peptides (GGPs) are recognized by the calcium-sensing receptor and induce kokumi taste. The contents of GGP have been...     

An improved microtitre enzyme immunoassay to measure the boar taint steroid 5α-androst-16-en-3-one in blood plasma of pigs

Androstenone (5α-androst-16-en-3-one) is a volatile steroid which is synthesized in boar testes and stored in high amounts in fat thus leading to an urine-like odor in pork. Whereas microtiter assays (MTA) exist for fat determination, measurement in blood with MTA was not yet possible. The system reported here is based on a specific antiserum and a horse radish peroxidase conjugate as tracer. For coating bovine serum albumin was avoided which otherwise would lead to unspecific binding. Blood plasma was extracted with n-hexane, solvent was evaporated in a vacuum centrifuge and the extract was taken up in buffer with 10% methanol. Assay sensitivity was 2.5pg/well (0.025ng/mL), specificity was confirmed by GC-MS (r=0.96; n=50) and inter- and intraassay variation were 4.9% and 5.9%, respectively. Thus an assay system is available for studies in pig production and in wildlife research due to pheromone activity also in other species.     

Quantitative determination of the representative triterpenoids in the extracts of Ganoderma lucidum with different growth stages using high-performance liquid chromatography for evaluation of their 5α-reductase inhibitory properties

For quantitative determination of 5 triterpenoid constituents, including one ganoderma alcohol (ganodermatriol) and four ganoderma acids (ganoderic acid TR, DM, A, and D), in the products of Ganoderma lucidum, an analytical system was developed using high-performance liquid chromatography. The mobile phase was a linear gradient of 2% AcOH/H₂O–CH₃CN, and the elution profile was monitored at 243 and 252 nm for ganoderma alcohols and acids, respectively. This system was applied to a quantitative determination of the constituents in the different stage of G. lucidum (BMC9049 strain). The analytical results indicated that the quantity and composition of these triterpenoids differed appreciably among various stages. The stage that showed the highest concentration of ganoderic acid DM and TR also showed the strongest 5α-reductase inhibitory activity. This stage (stage 5 of 6) is thus the prime stage for harvesting this strain. Further, the contents of 5α-reductase inhibitors such as ganoderic acid TR and DM in G. lucidum extracts could be a very useful indicator to assess their 5α-reductase inhibitory activity and verify their potency.     

Quantitative analysis of triterpenoids in different parts of Ilex hainanensis, Ilex stewardii and Ilex pubescens using HPLC–ELSD and HPLC–MS and antibacterial activity

An HPLC–ELSD method was first developed for the quantitative analysis of principle triterpenoids in Ilex hainanensis, Ilex stewardii and Ilex pubescens. The established method, with excellent precision, repeatability and recovery, was successfully applied to determine four triterpenoids in 24 samples from different species and medicinal parts of Ilex, and the changing trend was discussed. HPLC–ESI–MSⁿ was used for the identification of constituents in samples. The proposed method was simple, effective and suitable for investigations of these plants. Furthermore, the ethanol extracts from leaves of Ilex species, as well as their main components, were assessed for their antibacterial activities. The results indicated that the extracts of I. hainanensis, I. stewardii and I. pubescens could inhibit the growth of the tested oral pathogens, Streptococcus mutans and Actinomyces viscosu. Particularly, ilexgenin A was the most effective with MIC values of 7.8 and ?3.9 μg/ml, respectively.     

Study on the fingerprint profile of Monascus products with HPLC–FD,PAD and MS

Monascus products have been widely used as food additives and pharmaceuticals. Citrinin is a toxic metabolite produced during the Monascus fermentation. In this work, a quick extraction method with ultrasonic treatment was studied for a complete extraction of citrinin from the fungi cells. Furthermore, the proposed HPLC method has the advantage of the simultaneous determination of Monascus pigments and citrinin without sample pretreatment. Under the optimized HPLC conditions, a baseline resolution of pigments, citrinin and other catabolites was achieved. The detection limit of citrinin reached 0.5 ng mL⁻¹ (S/N > 3/1) with a fluorescence detector (FD). Eight Monascus pigments were detected, with photodiode array detector (PAD), two of which not yet described. The HPLC fingerprint profile of the eight Monascus pigments and citrinin appears significant for the quality control of the Monascus product.     

β-Glucoside metabolism in Oenococcus oeni: Cloning and characterisation of the phospho-β-glucosidase bglD

The structural gene for a phospho-β-glucosidase from the oenologically important lactic acid bacterium (LAB) Oenococcus oeni has been cloned and its protein product characterised. This gene is found in a putative β-glucosidase operon of 2178 base pairs encoding 4 genes designated bglA to bglD. The bglA, B and C genes were not cloned and characterised, however, are thought to be phosphoenolpyruvate dependent phospho transferase system (PEP-PTS) components IIC, IIA and IIB which regulate the uptake, phosphorylation and translocation of β-glucosides across the cytoplasmic membrane. The cloned bglD was sequenced and expressed in Escherichia coli followed by purification. The purified bglD protein has 480 residues, a molecular mass of 55.5 kDa and shows high homology to known phospho-β-glucosidases. bglD exhibited high activity towards the phosphorylated β-glucoside para-nitrophenol-β-d-glucopyranoside-6-phosphate with a pH optimum of 5.5 and maintained similar levels of activity between temperatures of 4 °C and 40 °C. The enzyme was not active against non-phosphorylated β-glucosides.     

Determination and quantification of the kokumi peptide, γ-glutamyl-valyl-glycine,in commercial soy sauces

Recent studies have demonstrated that kokumi substances, such as glutathione, are perceived through the calcium-sensing receptor (CaSR), and screening by CaSR assay and sensory evaluation has shown that γ-glutamyl-valyl-glycine (γ-Glu-Val-Gly) is a potent kokumi peptide. In this study, the contents of γ-Glu-Val-Gly in six commercial brands of dark-coloured soy sauces, two brands of light-coloured soy sauce, and one brand of white soy sauce, were investigated by high performance liquid chromatography–tandem mass spectrometry (LC/MS/MS), followed by derivatization with 6-aminoquinoyl-N-hydroxysuccinimidyl-carbamate (AQC). The analyses indicated that γ-Glu-Val-Gly was present in all investigated soy sauces at concentrations ranging from 0.15 to 0.61 mg/dl, demonstrating that it is widely distributed in soy sauces.     

In vitro screening of phenolic compounds, potential inhibition against α-amylase and α-glucosidase of culinary herbs in Thailand

Herbs that are commonly used in Thai dishes were selected for evaluation in order to determine their phenolic compounds, antioxidant activity, and in vitro potential inhibition against α-amylase and α-glucosidase. The total phenolic content ranged from 2.89 to 75.26 mg GAE/g dw. The three aqueous herb extracts with the highest total phenolic content were yellow-berried nightshade (Solanum xanthocarpum), holy basil (Ocimum sanctum) and acacia (Acacia pennata). The antioxidant activity was expressed as percent inhibition of DPPH, ranging from a high of 85% in bitter gourd (Monordica charantia) to a low of 0% in garlic (Allium sativum) and shallot (Allium cepa). A high correlation (r = 0.70, p < 0.05) was observed between total phenolic content and antioxidant activity for the herb extracts in the Solanaceae family while, an insignificant high and negatively correlation (r = −1.00, p > 0.05) for the herb extracts in the Cucurbitaceae and Umbelliferae families was observed. All of the herbs had caffeic content, varying from 0.00 to 23.93 mg/g dw. Peppermint (Mentha canalenisa), galangal (Languas galangal) and holy basil (O. sanctum) had a significant p-coumaric acid content. The first and second obtained principal component represented 60% of the total variation. The potential inhibition against α-amylase for the herbs extracts ranged from 0% to 58%, while the highest percentage was observed in the acacia (A. pennata) extract. The potential inhibition against α-glucosidase varied from 7% to 100%. A high correlation (r = 0.68, p < 0.05) was observed between α-amylase inhibition and caffeic acid content for aqueous extracts in the Alliaceae, Cucurbitaceae, and Leguminosae families, while a high correlation (r = 0.49, p < 0.05) was observed between α-glucosidase inhibition and total phenolic content for the aqueous extracts of all herbs. Therefore, specific culinary herbs showed to have a potential use for dietary management during the early stages of hyperglycaemia.     

α-Amylase inhibitory effect of 3β-olean-12-en-3-yl (9Z)-hexadec-9-enoate isolated from Spondias mombin leaf

Spondias mombin is a traditional herb used in the treatment of diabetes mellitus by traditional healers in southwest Nigeria. In this study, we investigated the antidiabetic activity using α-amylase inhibitory assay and isolated an active compound. The bioactivity assay-guided study demonstrated the presence of an α-amylase inhibitory fraction from S. mombin leaf. An active compound, 3β-olean-12-en-3-yl (9Z)-hexadec-9-enoate was also studied. This is reported, from this plant, for the first time. The methanol extract, diethyl ether fraction and the isolated compound exhibited significant enzyme inhibitory activity against Aspergillus oryzae α-amylase. Our study revealed, for the first time, the isolation and α-amylase inhibitory activity of 3β-olean-12-en-3-yl (9Z)-hexadec-9-enoate from S. mombin leaf.     

Simultaneous determination of aspartame,acesulfame-K,saccharin, citric acid and sodium benzoate in various food products using HPLC–CAD–UV/DAD

A newly developed method for simultaneous determination of aspartame, acesulfame-K, saccharin, citric acid and sodium benzoate in various diet supplements and non-alcoholic beverages in a single run is presented. The analytes were analysed by high-performance liquid chromatography coupled to a charged aerosol (Corona CAD) and ultraviolet–diode array detectors simultaneously connected in series. Mass spectrometer MicrOTOF-QII from Bruker Daltonik (Bremen, Germany) was used to obtain the mass spectra for peak identifications. The method was validated using a Thermo Hypersil Gold-C18 column packed with 5 μm shell particles (150 × 4.6 mm) and methanol–water with 0.05 % TFA gradient mobile phase at a flow rate of 0.80 mL/min. The elaborated method was validated for linearity, precision and accuracy. The analytical results obtained in the validation study were highly satisfying; the recoveries for the analytes studied ranged between 98.1 and 101 % and the precision values from 0.11 to 1.73 %. By these procedures, the three sweeteners (aspartame, acesulfame-K and saccharin), citric acid and sodium benzoate could be well separated and quantitatively determined in varied food products. Hundred millilitres of soft drinks contained on average 5.50 mg of aspartame, 6.38 mg of saccharin, 8.94 mg of acesulfame-K, 9.05 mg of sodium benzoate and 111 mg of citric acid. Citric acid was the most abundant additive in all the samples analysed except for table sweeteners, and its highest concentration was determined in diet supplements, i.e. 347 mg/g. The percentage of adequate daily intake realisation in case of all additives is lower than 10 %, except for sodium benzoate in isotonic drinks (10.1 %).     

Acidification,crushing and thermal treatments can influence the profile and stability of folate poly-γ-glutamates in broccoli (Brassica oleracea L. var. italica)

The influence of different treatments, i.e., crushing, high temperature short time (90 °C/4 min) (HTST) and low temperature long time (60 °C/40 min) (LTLT) blanching, acidification (pH 4.3), and sequences of these treatments on the folate poly-γ-glutamate profile and stability were investigated. In this study, broccoli was used as a case study. Regarding the folate poly-γ-glutamate profile, endogenous folate poly-γ-glutamates in broccoli florets were found predominantly as hepta- and hexa-γ-glutamates. Crushing raw broccoli, acidification and LTLT blanching enhanced folate deconjugation resulting in monoglutamate, di- and tri-γ-glutamates. Compared to other treatments, HTST blanching preformed prior to crushing resulted in the highest concentration of long chain poly-γ-glutamates. Regarding folate poly-γ-glutamates stability, acidification combined with LTLT blanching decreased folate stability whereas HTST blanching combined with different sequences of blanching and crushing did not affect folate poly-γ-glutamates stability. It was concluded that crushing (prior to heating), acidification and blanching could be strategically applied to increase the folate monoglutamate content of broccoli.     

Polyphenol characterization and encapsulation in β-cyclodextrin of a flavonoid-rich Hypericum perforatum (St John's wort) extract

Purified methanolic extracts of Hypericum perforatum (HP) from Northern Greece were very rich in flavonoids. Among simple polyphenols determined by GC-MS, epicatechin, catechin and quercetin predominated, their concentrations being 118.9 ± 20.6, 8.7 ± 1.4 and 5.8 ± 0.8 mg/g extract. LC-MS analysis revealed that the HP extract was mainly consisted of quercetin glucosides, catechin and quercetin. Among anthocyanins, malvidine was present at 1.96 ± 0.2 mg/g. The 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and the ferric reducing antioxidant power (FRAP) assays showed that the HP extract exerted significant antioxidant activity. The inclusion complex of HP with β-cyclodextrin (β-CD) was prepared by mixing 1:4 mass ratios of its components in aqueous media and subsequent freeze-drying. The encapsulation was verified by differential scanning calorimetry (DSC) and NMR studies, and encapsulation efficiencies were 27.5, 30.0 and 35.0% for catechin, epicatechin and quercetin respectively. DSC after thermal oxidation indicated that the inclusion complex remained intact at temperatures where the free HP extract was oxidized. It is concluded that the encapsulation in β-CD improves the thermal stability of nutraceutical antioxidants present in St John's wort extract, suggesting that the inclusion complex could serve as a flavonoids-rich food supplement or a novel additive to enhance the antioxidant capacity of fresh or thermally processed food.     

Effects of hydroalcoholic α-galactoside extraction and phytase supplementation on the nutritive utilization of manganese,iron, zinc and potassium from lupin (Lupinus albus var. multolupa)-based diets in growing rats

The effects of α-galactoside removal, using a hydroalcoholic extraction process and phytase supplementation, on the digestive and metabolic utilization of total ash, Mn, Fe, Zn and K from Lupinus albus var. multolupa-based diets by growing rats were evaluated, using a balance technique, and compared to the results obtained using a casein–cystine control diet. The specific amount of minerals needed to complement those provided by the lupin flours and casein in order to reach the target requirements of the growing rat were supplemented as heme or non-heme iron sources or in the form of inorganic salts in the case of Zn or K. The nutritive utilization of total ash, Mn, Fe and Zn was higher from raw and α-galactoside-free lupin flour diets than from the casein–cystine control or the phytase-supplemented diets, whereas smaller differences were found regarding the nutritive utilization of K. Differences in mineral retention were reflected in changes of the mineral contents of some tissues, which varied among the different cations studied.     

High performance liquid chromatography method for the simultaneous determination of α-, γ- and δ-tocopherol in vegetable oils in presence of hexadecyltrimethylammonium bromide/n-propanol in mobile phase

A rapid methodology by RP-HPLC, 10 min of total analysis time, for the analysis of α-, γ- and δ-tocopherol in vegetable oils, in presence of retinol, retinyl acetate and α-tocopherol acetate was developed. Hexadecyltrimethylammonium bromide 0.1 M/n-propanol 65% (v/v) are used as mobile phase. Tocopherols were detected using UV and fluorescence detection. The quantification limits for α-, γ- and δ-tocopherols were 0.28, 0.12 and 0.23 mg L⁻¹, respectively. The method yielded satisfactory results when it was applied to vegetable oils and thus, it is suitable for their quality control.     

Modulation of the bovine innate immune response by production of 1α,25-dihydroxyvitamin D3 in bovine monocytes

In cattle, the kidney has been the only known site for production of 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] from 25-hydroxyvitamin D₃ [25(OH)D₃] by 1α-hydroxylase (1α-OHase). Based on human studies, it was hypothesized that bovine monocytes could produce 1,25(OH)₂D₃ upon activation and 1,25(OH)₂D₃ would regulate expression of vitamin D-responsive genes in monocytes. First, the effects of 1,25(OH)₂D₃ on bovine monocytes isolated from peripheral blood were tested. Treatment of nonstimulated monocytes with 1,25(OH)₂D₃ increased expression of the gene for the vitamin D 24-hydroxylase (24-OHase) enzyme by 51 ± 13 fold, but 1,25(OH)₂D₃ induction of 24-OHase expression was blocked by lipopolysaccharide (LPS) stimulation. In addition, 1,25(OH)₂D₃ increased the gene expression of inducible nitric oxide synthase and the chemokine RANTES (regulated upon activation, normal T-cell expressed and secreted) in LPS-stimulated monocytes 69 ± 13 and 40 ± 12 fold, respectively. Next, the ability of bovine monocytes to express 1α-OHase and produce 1,25(OH)₂D₃ was tested. Activation of monocytes with LPS, tripalmitoylated lipopeptide (Pam3CSK4), or peptidoglycan caused 43 ± 9, 17 ± 3, and 19 ± 3 fold increases in 1α-OHase gene expression, respectively. Addition of 25(OH)D₃ to LPS-stimulated monocytes enhanced expression of inducible nitric oxide synthase and RANTES and nitric oxide production in a dose-dependent manner, giving evidence that activated monocytes convert 25(OH)D₃ to 1,25(OH)₂D₃. In conclusion, bovine monocytes produce 1,25(OH)₂D₃ in response to toll-like receptor signaling, and 1,25(OH)₂D₃ production in monocytes increased the expression of genes involved in the innate immune system. Vitamin D status of cattle might be important for optimal innate immune function because 1,25(OH)₂D₃ production in activated monocytes and subsequent upregulation of inducible nitric oxide synthase and RANTES expression was dependent on 25(OH)D₃ availability.