Purification, chemical characterization, and antioxidant activity of a polysaccharide from the fruiting bodies of sanghuang mushroom (Phellinus baumii Pilát)

A purified water-soluble polysaccharide was isolated from the fruiting bodies of sanghuang mushroom (Phellinus baumii Pilát) using hot water extraction, DEAE Sepharose Fast Flow anion exchange and High-Resolution Sephacryl S-1000 gel-filtration chromatography. The purified polysaccharide was a complex β-d-glucan, with a molecular mass of 230 kDa. Fourier-transform infrared (FT-IR), methylation analysis, and NMR spectroscopy of sanghuang mushroom polysaccharide (PBF3) indicated that the polysaccharide contained (1→3)-β-d-, (1→4)-β-d-, and branched (1→3,6)-β-d-glucopyranosyl residues. On the basis of hydroxyl radical assay, superoxide radical assay, and DPPH radical assay, its antioxidant activities were investigated. PBF3 had significant effect on scavenging hydroxyl radicals, an equivalent inhibiting ability to vitamin C on superoxide radical, and a little lower scavenging activity on DPPH radical than vitamin C, and should be explored as a novel potential antioxidant.     

Study of galacto‐oligosaccharide formation from lactose using Pectinex Ultra SP‐L

BACKGROUND: Galacto‐oligosaccharides (GOS) are synthesised from lactose by transglycosylation using β‐galactosidase (EC 3.2.1.23) and are recognised as prebiotics. The commercial enzyme preparation Pectinex Ultra SP‐L produced by Aspergillus aculeatus possesses β‐galactosidase activity; however, because its use has been directed towards the formation of 6′‐β‐galactosyl‐lactose, no data have been reported on the formation of other GOS. Since the composition of the oligosaccharide mixture obtained during lactose hydrolysis may affect the prebiotic properties, in this study the influence of various parameters (pH, temperature, time and enzyme and lactose concentrations) on the formation of GOS using Pectinex Ultra SP‐L was investigated. RESULTS: High‐performance anion exchange chromatography with pulsed amperometric detection (HPAEC‐PAD) analysis allowed the detection of disaccharides other than lactose, trisaccharides and minor amounts of higher‐molecular‐weight GOS. The main GOS formed were a trisaccharide identified as β‐D ‐Galp‐(1 → 6)‐Lac (6′‐β‐galactosyl‐lactose) and a disaccharide identified as β‐D ‐Galp‐(1 → 6)‐D ‐Gal (galactobiose). Other GOS detected were tentatively identified as β‐D ‐Galp‐(1 → 6)‐D ‐Glc (allolactose), β‐D ‐Galp‐(1 → 3)‐D ‐Glc and β‐D ‐Galp‐(1 → 3)‐Lac. Trisaccharide formation was favoured by a pH increase from 4.5 to 6.5, whereas the disaccharide content increased as the pH decreased, reaching a level of 11% at pH 4.5. 6′‐β‐Galactosyl‐lactose production increased gradually with increasing temperature, attaining a maximum value of 17% at 60 °C after 7 h, whereas disaccharide formation was optimal at 50 °C, reaching a level of 10% after 24 h. CONCLUSION: The results indicate that Pectinex Ultra SP‐L can be used to obtain GOS mixtures of different composition depending on the operating conditions. It has been shown for the first time that Pectinex Ultra SP‐L can be used for the selective formation of disaccharides. Copyright © 2008 Society of Chemical Industry     

Structural studies of an acidic polysaccharide of Mesona blumes gum

Mesona blumes gum can be isolated into a neutral polysaccharide (NMBG) and an acidic polysaccharide (AMBG). The yield of AMBG can be up to 90% (w/w). AMBG with a molecular weight of 6566 Da is composed of galactose, glucose, mannose, xylose, arabinose, rhamnose and galacturonic acid in the molar ratio 2.66:1:0.37:2.29:12.5:5.99:23.5. Structural features of the purified AMBG were investigated by a combination of chemical and instrumental analysis, such as periodate oxidation, Smith degradation, methylation, and ¹³C and ¹H NMR. It was found that AMBG possessed a (1 → 4)‐α‐galacturonan backbone with some insertions of (1 → 2)‐α‐L ‐Rhap residues. The branches of arabinogalactan, arabinan, galactan and xylan were all attached to the backbone via O‐4 of α‐L ‐Rhap residues. In addition, some α‐L ‐Rhap residues on the backbone terminated with α‐L ‐Araf and some O‐6 in galacturonic acid residues were acetylated or methyl esterified. The molecular structure of AMBG at different concentrations was observed by atomic force microscopy (AFM). It was found that AMBG showed spherical lumps at 1 µg mL^?1 but an irregular worm‐like shape at 10 µg mL^?1, which indicated that the viscosity of AMBG might be caused by its notable molecular aggregation. Copyright © 2007 Society of Chemical Industry     

Hydrolytic enzyme activities as indicators of fungal spoilage in bakery products

Cake analogues were prepared at different a_w (0.80, 0.85 and 0.90) and pH (6 and 7.5) levels and inoculated with a range of seven representative moulds of spoilage mycoflora of bakery products. The responses recorded were colony radii after 1, 2, 3 and 4 weeks as well as microbial counts and total and specific activities of six hydrolytic enzymes after 4 weeks. Multivariate analysis was applied in order to determine correlations among the responses and thus assess the suitability of using enzyme activities as estimators for fungal growth. The results showed that enzyme activities correlated with growth parameters for Aspergillus and Penicillium isolates, although the useful enzymes were not the same for the three isolates tested. The correlation was poor, however, for Eurotium isolates. In general, specific activities of some enzymes showed better correlation with growth parameters, with α‐D ‐galactosidase, β‐D ‐galactosidase, β‐D ‐glucosidase and N‐acetyl‐β‐D ‐glucosaminidase being the more useful enzymes among those assayed. © 2003 Society of Chemical Industry     

Structural characterization and antioxidant activities of 2 water-soluble polysaccharide fractions purified from tea (Camellia sinensis) flower

Abstract: The water‐soluble crude polysaccharide tea flower polysaccharide (TFP), obtained from tea (Camellia sinensis) flower by boiling‐water extraction and ethanol precipitation, was fractionated by Sephadex G‐100 column chromatography, giving 2 polysaccharide fractions termed TFP‐1 and TFP‐2. The structural features of TFP‐1 and TFP‐2 were investigated by high‐performance liquid chromatography (HPLC), gel‐permeation chromatography (GPC), rheometer, infrared (IR) spectra, nuclear magnetic resonance (NMR) spectroscopy, atomic force microscope (AFM), and scanning electron microscope (SEM). Results indicated that TFP‐1 was composed of glucose: xylose: rhamnose: galactose = 1.0:1.2:0.81:0.98 with a molecular weight of 167.5 KDa, while TFP‐2 comprised glucose: xylose: rhamnose: arabinose = 1.0:0.76:2.3:2.3 with a molecular weight of 10.1 KDa. The ¹H NMR revealed that TFP‐1 contained α‐L‐Rhap, α‐D‐Galp, α‐D‐GalpNAc, α‐D‐Xylp, α‐D‐Glcp, and β‐D‐Glcp residues, while TFP‐2 was illustrated to have α‐L‐Rhap, α‐L‐Arap, α‐D‐Xylp, α‐D‐Glcp, and α‐D‐GlcpNAc residues. Antioxidant activities of these fractions were investigated using various in vitro assay systems compared with ascorbic acid. In conclusion, TFP‐2 exhibited the higher antioxidant activities and could be explored as a novel potential antioxidant. Practical Application: At present, commonly low‐grade tea is preferred to extract the tea polysaccharide, to take full advantage of tea flower resource to extract polysaccharides can greatly reduce the cost of tea products. Thus, the search for plant‐derived biomaterials from this study could generate natural value‐added products from underutilized tea plant waste and used as a medicinal agent against chronic health problems, such as cancers, aging, and atherosclerosis caused by reactive free radicals that produced from oxidation.     

The age of cows as a factor shaping the antioxidant level during a nutritional experiment with fish oil and linseed supplementation for increasing the antioxidant value of milk

BACKGROUND: So far, in research studies, the age of cows has not been considered as a factor that may influence the changes in the content of milk ingredients with antioxidant properties modified by the feed supplementation. The aim of this study was to determine the influence of supplementation on the content of ingredients having antioxidant properties and to determine the influence of the age of cows taking part in the experiment on these changes. The experiment was conducted using 20 Polish Holstein Friesian cows, 10 primiparous and 10 multiparous. The combined supplementation of fish oil and linseed constituted the experimental factor. RESULTS: The milk of primiparous cows after 21 days of supplementation was characterised by a higher content of C18:1 trans ‐11, C18:2 cis ‐9, trans ‐11, α‐retinol, α‐tocopherol and β‐lactoglobulin compared to the milk of multiparous cows, in which a higher level of lactoferrin, C20:5 and β‐carotene was recorded. In both groups an increase in the total antioxidant status was noted (a higher level in the milk of primiparous cows). CONCLUSIONS: Modification of the diet of cows with fish oil and linseed significantly influenced antioxidant properties of their milk; however, the response of multiparous and primaparous cows was noticeably different to the supplement introduced. Copyright © 2012 Society of Chemical Industry     

Structural Characterization and Antifatigue Effect In Vivo of Maca (Lepidium meyenii Walp) Polysaccharide

Maca (Lepidium meyenii Walp) polysaccharides (MP) with purity of 99.2% were obtained to investigate their structural characteristics and antifatigue effect in vivo. The physicochemical properties of MP were analyzed through high‐performance gel filtration chromatography, IR, monosaccharide composition, methylation, GC‐MS, and NMR analyses. The antifatigue effect of MP was evaluated by using a mouse weight‐loaded swimming model. MP is an acidic heteropolysaccharide with an average molecular weight (M_w) of 793.5 kDa. It is composed of D‐GalA: D‐Glc: L‐Ara: D‐Man: D‐Gal: L‐Rha = 35.07:29.98:16.98:13.01:4.21:0.75 (mol, %). The findings revealed that MP contained β‐1,3‐Galp(A), β‐1,3‐Glcp, and α‐1, 3‐Manp linked alternatingly to form a backbone (5:4:1). MP (above mid‐dosage 50 mg/kg bw/d) could effectively elongate swimming durations and accelerate average swimming speeds (within the 1st 5 min) of mice (P < 0.05) and improve the serous biochemical parameters of mice. Compared with the control model, high‐dosage (100 mg/kg bw/d) MP treatment could significantly enhance glutathione peroxidase and creatine kinase activities (P < 0.05) and decreased lactate dehydrogenase activity (P < 0.01). High‐dosage MP could significantly reduce the levels of blood urea nitrogen, lactic acid, and malondialdehyde (P < 0.05). MP is an acidic polysaccharide with a high D‐GalA content, which could be responsible for the antifatigue effect of maca.     

α‐l‐Rhamnosidase from Aspergillus flavus MTCC‐9606 isolated from lemon fruit peel

An α‐l ‐rhamnosidase producing fungal strain has been isolated from decaying lemon fruit. The fungal strain has been identified as Aspergillus flavus. The α‐l ‐rhamnosidase has been purified from the culture filtrate of the fungal strain using ultra filtration and cation exchange chromatography on carboxy methyl (CM) cellulose. The molecular mass of the purified enzyme determined by SDS–PAGE analysis was 41 kDa. The K_m values of the enzyme using p‐nitrophenyl‐α‐l ‐rhamnopyranoside and naringin as the substrates were 1.89 and 1.6 mm respectively. The pH and temperature optima of the enzyme were 11.0 and 50 °C respectively. The effects of various chemical species present in grape fruit juice and wine on the activity of the enzyme have been determined.     

Isolation and chemical characterisation of a polysaccharide from green tea (Camellia sinensis L.)

BACKGROUND: To contribute towards understanding the relationship of structure and bioactivity, a protein‐bound acidic polysaccharide named TPC3‐1 was isolated and purified from low‐grade green tea (Camellia sinensis L.). The homogeneity and weight average molecular weight of TPC3‐1 was determined by agarose gel electrophoresis and high‐performance gel permeation chromatography. The monosaccharide and amino acid composition of TPC3‐1 were analysed by gas chromatography and an amino acid analyser. The molecular structure of TPC3‐1 was characterised by Fourier transform infrared spectroscopy, ¹³C nuclear magnetic resonance spectroscopy and atomic force microscopy. RESULTS: Based on the data obtained, the average peak molecular weight of TPC3‐1 was about 120 kDa. TPC3‐1 was composed of L ‐arabinose, D ‐ribose, D ‐xylose, D ‐glucose and D ‐galactose with a molar ratio of 4.9:2.2:3.1:1.8:1.0. Fifteen amino acids were identified as components of the polymer. The TPC3‐1 molecule was found to have an anomeric carbon sign of both α and β configurations and high‐branched chains. The network structure of TPC3‐1 was observed. CONCLUSION: The tea polysaccharide TPC3‐1 was an acid protein‐bound polysaccharide with an image of network structure. The results presented here will facilitate further study of the relationship between the chemical structure and biological role of tea polysaccharide. Copyright © 2008 Society of Chemical Industry     

Changes in volatile compound composition of Antrodia camphorata during solid state fermentation

BACKGROUND: Although the volatiles present in mushrooms and fungi have been investigated by many researchers, including Antrodia camphorata in submerged fermentation, there are few data available regarding changes in volatile compounds during fermentation. Our research has revealed that solid state fermentation of A. camphorata is highly odiferous compared with submerged cultures and the odor changed with increasing culture time. Therefore the aim of this study was to investigate the changes in volatile compound composition of A. camphorata during solid state fermentation. RESULTS: Altogether, 124 major volatile compounds were identified. The volatile compounds produced by A. camphorata during growth in solid state fermentation were quite different. Oct‐1‐en‐3‐ol, octan‐3‐one and methyl 2‐phenylacetate were predominant in exponential growth phase production, while the dominant volatiles produced in stationary phase were octan‐3‐one and methyl 2‐phenylacetate. In stationary phase, lactone compounds in A. camphorata, such as 5‐butyloxolan‐2‐one, 5‐heptyloxolan‐2‐one, 6‐heptyloxan‐2‐one, contributed greatly to peach and fruit‐like flavor. Terpene and terpene alcohol compounds, such as 1‐terpineol, L ‐linalool, T‐cadinol, (E, E)‐farnesol, β‐elemene, cis‐α‐bisabolene and α‐muurolene, made different contributions to herbal fresh aroma in A. camphorata. Nineteen volatile sesquiterpenes were detected from solid state fermentation of A. camphorata. The compounds 5‐n‐butyl‐5H‐furan‐2‐one, β‐ionone, (?)‐caryophyllene oxide, aromadendrene oxide, diepi‐α‐cedrene epoxide, β‐elemene, α‐selinene, α‐muurolene, azulene, germacrene D, γ‐cadinene and 2‐methylpyrazine have not hitherto been reported in A. camphorata. CONCLUSION: The preliminary results suggest that the aroma‐active compounds produced by A camphorata in solid state fermentation might serve as an important source of natural aroma compounds for the food and cosmetic industries or antibiotic activity compounds. The sesquiterpenes could be identified as possible taxonomic markers for A. camphorata. Copyright © 2011 Society of Chemical Industry     

Mycotoxicogenic fungal inhibition by innovative cheese cover with aromatic plants

BACKGROUND: The use of aromatic plants and their extracts with antimicrobial properties may be compromised in the case of cheese, as some type of fungal starter is needed during its production. Penicillium verrucosum is considered a common cheese spoiler. The aim of this study was to evaluate the innovative use of certain aromatic plants as natural cheese covers in order to prevent mycotoxicogenic fungal growth (P. verrucosum). A collection of 12 essential oils (EOs) was obtained from various aromatic plants by solvent‐free microwave extraction technology, and volatile characterisation of the EOs was carried out by gas chromatography/mass spectrometry. RESULTS: The most effective EOs against P. verrucosum were obtained from Anethum graveolens, Hyssopus officinalis and Chamaemelum nobile, yielding 50% inhibition of fungal growth at concentration values lower than 0.02 µL mL^?1. All EOs showed high volatile heterogeneity, with α‐phellandrene, pinocamphone, isopinocamphone, α‐pinene, camphene, 1,8‐cineole, carvacrol and trans‐anethole being found to be statistically significant in the antifungal model. CONCLUSION: The use of these aromatic plants as natural covers on cheese can satisfactorily inhibit the growth of some mycotoxicogenic fungal spoilers. Among the volatile compounds present, α‐ and β‐phellandrene were confirmed as the most relevant in the inhibition. © 2012 Society of Chemical Industry     

Flavan‐3‐ol C‐glycosides – Preparation and model experiments mimicking their human intestinal transit

In order to study the human intestinal transit of flavan‐3‐ol C‐glycosides, several C‐glycosyl derivatives were prepared by non‐enzymatic reaction of (+)‐catechin with α‐D ‐glucose, α‐D ‐galactose and α‐D ‐rhamnose, respectively. In contrast to literature data, we propose that the reaction mechanism proceeds in analogy to the rearrangement of flavan‐3‐ols during epimerization under alkaline conditions. Four of the 12 synthesized flavan‐3‐ol C‐glycosides were incubated under aerobic conditions at 37°C using saliva (2 min) and simulated gastric juice (3 h). To simulate human intestine, the C‐glycosides were also incubated under anaerobic conditions at 37°C both in human ileostomy fluid (10 h) and colostomy fluid (24 h), respectively. The flavan‐3‐ol C‐glycosides under study, i.e. (+)‐epicatechin 8‐C‐β‐D ‐glucopyranoside (1a), (+)‐epicatechin 6‐C‐β‐D ‐glucopyranoside (1d), (+)‐catechin 6‐C‐β‐D ‐galactopyranoside (2b), (+)‐catechin 6‐C‐β‐D ‐rhamnopyranoside (3b) were analyzed in the incubation samples by HPLC‐DAD and HPLC‐DAD‐MS/MS. They were found to be stable in the course of incubation in saliva, simulated gastric juice and ileostomy fluid and underwent degradation in colostomy fluid. While the 6‐C‐β‐D ‐glucopyranoside 1d was completely metabolized between 2 and 4 h, decomposition of the 6‐C‐β‐D ‐galactopyranoside 2b reached only 16±2% within 4 h of incubation. Linear degradation rates of 1d and 2b in colostomy fluid differed significantly. As microbial metabolism of flavan‐3‐ols is known not to be influenced by the stereochemistry of the aglycon, varying degradation rates are ascribed to the effect of the sugar moiety. Based on these results we assume that flavan‐3‐ol C‐glycosides pass through the upper gastrointestinal tract (oral cavity, stomach and small intestine) unmodified and are then metabolized by the colonic microflora.     

Isolation of a free radical‐scavenging antioxidant from water spinach (Ipomoea aquatica Forsk)

Ipomoea aquatica Forsk, a green leafy vegetable that is a rich source of vitamins and amino acids with many health benefits, has been explored for the isolation and identification of its bioactive compounds. Activity‐guided repeated fractionation of a methanol extract on a silica gel column followed by an XAD column yielded a compound that exhibited antioxidant activity with an EC₅₀ value of 83 ± 1.02 µg ml^?1 reaction mixture. It also showed very strong lipid peroxidation‐inhibitory activity in a liposome model system with an EC₅₀ value of 72.2 ± 0.9 µg ml^?1. However, it showed negligible metal‐chelating activity. Based on UV, 2D nuclear magnetic resonance and gas chromatography/mass spectrometry studies, the compound was tentatively identified to be 7‐O‐β‐D ‐glucopyranosyl‐dihydroquercetin‐3‐O‐α‐D ‐glucopyranoside. This is the first report on the antioxidant properties of I aquatica leaf extracts. Copyright © 2005 Society of Chemical Industry     

In Vitro Fermentation Behavior of Isomalto/Malto‐Polysaccharides Using Human Fecal Inoculum Indicates Prebiotic Potential

1 Scope

This study characterize intestinal fermentation of isomalto/malto‐polysaccharides (IMMPs), by monitoring degradation of IMMPs, production of short chain fatty acids (SCFAs), lactic acid, and succinic acid as well as enzyme activity and microbiota composition.

2 Methods and results

IMMP‐94 (94% α‐(1→6) glycosidic linkages), IMMP‐96, IMMP‐27, and IMMP‐dig27 (IMMP‐27 after removal of digestible starch segments) are fermented batchwise in vitro using human fecal inoculum. Fermentation digesta samples are taken for analysis in time up till 48 h. The fermentation of α‐(1→6) glycosidic linkages in IMMP‐94, IMMP‐96, and IMMP‐dig27 starts after 12 h and finishes within 48 h. IMMP‐27 fermentation starts directly after inoculation utilizing α‐(1→4) linked glucosyl residues; however, the utilization of α‐(1→6) linked glucoses is delayed and start only after the depletion of α‐(1→4) linked glucose moieties. SCFAs are produced in high amounts with acetic acid and succinic acid being the major products next to propionic acid and butyric acid. The polysaccharide fraction is degraded into isomalto‐oligosaccharides (IMOs) mainly by extracellular enzymes. The smaller IMOs are further degraded by cell‐associated enzymes. Overall microbial diversity and the relative abundance of Bifidobacterium and Lactobacillus, significantly increase during the fermentation of IMMPs.

3 Conclusion

IMMP containing segments of α‐(1→6) linked glucose units are slowly fermentable fibers with prebiotic potential.     

Diet high in oat β-glucan activates the gut-hypothalamic (PYY₃₋₃₆-NPY) axis and increases satiety in diet-induced obesity in mice

This study tested the effects of (1→3),(1→4) β‐D ‐glucan from oats, on activation of the gut‐hypothalamic (PYY_3–36‐NPY) axis, satiety, and weight loss in diet‐induced obesity (DIO) mice. DIO mice were fed standard lab chow diets or varied doses of β‐glucan for 6 weeks. Energy intake, satiety, body weight changes and peptide Y‐Y_3‐36 (PYY_3‐36) were measured together with a satiety test and measurement of neuropeptide Y (NPY) mRNA expression in the hypothalamic arcuate nucleus (Arc). The average energy intake (‐13%, p<0.05) and body weight gain was lower with increasing β‐glucan over 6 wk with acute suppression of energy intake over 4 h. The highest β‐glucan diet significantly increased plasma PYY_3‐36, with suppression of Arc NPY mRNA.     

Structural characterisation and immunomodulatory effects of polysaccharides isolated from Dendrobium aphyllum

A crude polysaccharide extract of Dendrobium aphyllum (cDAP, yield 38.15 ± 0.20%) was generated. The D. aphyllum polysaccharide (DAP, M_w 471.586 kDa), purified by DEAE‐Sepharose and Sephadex‐G200 Fast Flow, was composed of mannose (71.3%) and glucose (28.7%), according to GC–MS analysis. Its backbone was composed of β‐d ‐mannopyranose and β‐d ‐glucopyranose residues, as revealed by infrared spectroscopic analysis. Its glycosidic bond was mainly 1, 4‐linked, and the O‐acetyl groups were mainly linked to mannose residues, according to periodate oxidation and Smith degradation analysis. The DAP units polymerised into a filiform‐shaped spatial pattern, as characterised by atomic force microscopy and scanning electron microscopy. DAP treatment enhanced cytokine secretion (nitric oxide, interleukin‐6 and tumour necrosis factor‐α) and pinocytic and phagocytic capacities of RAW 264.7 mouse macrophages. The complement receptor 3 and mannose receptor were identified to be the receptors of DAP on RAW 264.7 cells, indicating that the Akt/mTOR/MAPK and IKK/nuclear factor‐?B pathways could be involved in DAP‐activated immunomodulation.     

Purification,characterisation and application of α‐l‐rhamnosidase from Penicillium citrinum MTCC‐8897

An α‐l ‐rhamnosidase secreted by Penicillium citrinum MTCC‐8897 has been purified to homogeneity from the culture filtrate of the fungal strain using ammonium sulphate precipitation and cation‐exchange chromatography on carboxymethyl cellulose. The sodium dodecyl sulphate/polyacrylamide gel electrophoresis analysis of the purified enzyme gave a single protein band corresponding to the molecular mass 51.0 kDa. The native polyacrylamide gel electrophoresis also gave a single protein band confirming the enzyme purity. The K_m and V_max values of the enzyme for p‐nitrophenyl α‐l ‐rhamnopyranoside were 0.36 mm and 22.54 μmole min^?1 mg^?1, respectively, and k_cat value was 17.1 s^?1 giving k_cat/K_m value of 4.75 × 10⁴ m ^?1 s^?1. The pH and temperature optima of the enzyme were 7.0 and 60 °C, respectively. The purified enzyme liberated l ‐rhamnose from naringin, rutin, hesperidin and wine, indicating that it has biotechnological application potential for the preparation of l ‐rhamnose and other pharmaceutically important compounds from natural glycosides containing terminal α‐l ‐rhamnose and also in the enhancement of wine aroma.     

Physicochemical,structural, and digestibility properties of enzymatic modified plantain and mango starches

The effect of two enzymatic treatments (increasing the branch density of starch and shortening of AP and amylose chains) on the fraction of slowly digestible starch (SDS) and resistant starch (RS) of plantain (Musa paradisiaca L.) and mango (Mangifera indica L.) starches was investigated. The enzymatic modifications were carried out using β‐amylase (β‐AMY) and β‐amylase‐transglucosidase (β‐AMY‐TGs), in gelatinized starches. Plantain starch showed an increase from 10.9 to 18.5% of SDS, when it was modified by β‐AMY‐TGs, while the treatment with β‐AMY alone showed reduction from 10.9 to 7.1% in SDS. RS content increased with both treatments. On the other hand, mango starch showed an increase in SDS from 6.3 to 22.3% using β‐AMY treatment and from 6.3 to 11.7% using β‐AMY‐TGs treatment. The latter treatment also increased RS content. The enzyme modified starches showed a reduction in the values of molar mass and gyration radius compared with the native starch. The content of short chains of AP, particularly in the DP range 5–12, increased, the percentage of crystallinity decreased in treated starches, and ¹H NMR spectra showed a significant increase of α‐(1 → 6) linkages in the starches modified with β‐AMY‐TGs. These characteristics were related to an increase in the slow and resistant digestion properties of plantain and mango starches.     

In vitro degradation by mixed rumen bacteria of 17 mono‐ and sesquiterpenes typical of winter and spring diets of goats on Basilitica rangelands (southern Italy)

BACKGROUND: Nine monoterpenes (δ‐3‐carene, p‐cymene, limonene, β‐myrcene, (E)‐ and (Z)‐β‐ocimene, α‐phellandrene, α‐terpinene, γ‐terpinene), seven oxygenated monoterpenes (1,8‐cineole, linalool, (E)‐ and (Z)‐linalool oxide, 4‐terpinenol, α‐terpineol, α‐terpinolene) and one sesquiterpene (β‐cedrene) were investigated for their degradability in the rumen microbial ecosystem. These molecules were identified as dominant terpenes in the winter and spring diets of milking goats in Basilicata (southern Italy). RESULTS: All terpenes were tested at 3.33 µL L^?1 for 24 h using in vitro incubation with mixed rumen bacteria from dairy goats. Oxygen‐containing compounds were those recovered at the highest levels (89% of (E)‐linalool oxide, 93% of (Z)‐linalool oxide, 91% of 1,8‐cineole, 82% of terpineol and 72% of 4‐terpinenol), except linalool. The linear alkenes β‐myrcene and β‐ocimene almost completely disappeared. Results were more variable among cyclic alkenes, with recovery rates ranging from 50% in the case of limonene to less than 1% for α‐phellandrene. 17% of the only sesquiterpene of the group, β‐cedrene, was recovered. CONCLUSION: Recovery rates differed markedly among terpenes, partly in relation to the presence of oxygen and rings in the molecules. These observations should contribute to a better understanding of the changes in composition between the diet and milk terpenes. Copyright © 2008 Society of Chemical Industry