Evaluation of whisky distillery by-products III.—Effect of calcium supplements on the digestibility and intake of ruminant diets containing malt distiller's grains

Digestibility and intake data have been obtained from sheep fed on rations consisting of fresh and ensiled malt distiller's grains (MDG) fed alone and with hay and silage. The effects of calcium supplements have been measured with all rations, and calcium lactate has been compared with calcium carbonate. The results of digestibility trials with cattle have been included; in these the effect of additional calcium has been estimated with rations of barley straw + MDG. When MDG was fed alone the intakes of fresh and ensiled forms were similar and there was a significant decrease in intake with duration of feeding. Fresh MDG had a significantly higher digestibility, and additional calcium increased the digestibilities of fresh and ensiled samples. The intakes of rations containing hay + MDG and silage + MDG were positively correlated with digestibilities of the whole ration. Additional calcium resulted in higher intakes of hay and MDG but silage intakes were unaffected. The effect of added calcium was greater with hay + fresh MDG than with other combinations of constituents. Calcium carbonate and calcium lactate were equally effective in increasing intake. The addition of NaCl during the ensilage of MDG reduced the retention of magnesium by sheep given grains with hay and silage. Addition of calcium to cattle rations of barley straw and MDG produced an increase in the intake but digestibility of the diet was not affected. The rations with calcium provided 0·75 × maintenance requirements of the cattle for metabolisable energy and about twice the maintenance requirements for digestible crude protein.     

Evaluation of whisky distillery by-products. II. Studies on the in vitro digestibility of malt distiller's grains

The in vitro digestibility technique has been used to determine the organic matter digestibility (OMD) of dried samples of malt distiller's grains (MDG). The method gave highly reproducible results for OMD of fresh and ensiled samples when different batches of rumen liquor from hay-fed sheep were used. The results were consistently lower than values determined by in vivo digestibility trials. The OMD values were increased by raising the calcium ion Concentration of the digesta and by extraction of lipids from the MDG samples. The addition of calcium had no effect on fat-extracted samples of MDG.     

Evaluation of whisky distillery by-products. I. Chemical composition and losses during transport and storage of malt distiller's grains

Samples of wet malt distiller's grains (MDG) have been analysed to assess the quality of the material and the variation between the effects of distilleries on quality and the losses incurred during transport and farm storage. Comparative analyses of MDG and the parent barley showed that the recoveries of soluble carbohydrate, protein, holocellulose, lipid and minerals in the MDG and malt culms amounted to 16, 54, 90, 95 and 32% respectively, which indicates a depletion of soluble carbohydrate and minerals (particularly potassium) and a concentration of structural components and lipid. A survey of the material leaving 12 different distilleries over a period of 6 weeks showed little difference in composition between distilleries. Transport losses were negligible. Losses of dry matter during storage ranged from 11 to 21 % depending on length of storage. The addition of salt did not result in a consistent reduction in these losses.     

Evaluation of whisky distillery by-products. VI. The reduction in digestibility of malt distiller's grains by fatty acids and the interaction with calcium and other reversal agents

In vitro methods have been used to study the inhibitory effects of fat and fatty acids which reduce the digestibility of malt distiller's grains (MDG). Glycerol and individual fatty acids below C⁸ in the homologous series do not produce any measurable decrease in digestibility. Capric acid lowers digestibility appreciably and the depression is even greater with lauric acid. Myristic, palmitic and stearic acids are less active than lauric and the greatest depressions were recorded with the unsaturated acids which showed greater activity with increasing unsaturation. Calcium salts produced partial reversal of digestibility in the presence of saturated acids above C¹⁰ and substantially greater reversal with the C¹⁸ unsaturated acids. The reduction in digestibility of MDG and in steam volatile acid production in the digesta by the presence of native fat may be attributed to the high content of oleic and linoleic acids which can also account for the marked reversal of effects by calcium. Alkaline earth metals and iron were examined for reversibility but only calcium produced consistent effects. Addition of ergocalciferol produced reversal effects similar to calcium. The reversal by calcium was evident when the calcium was added to the digesta up to 8 h after the commencement of incubation which indicates that the fatty acids have a bacteriostatic effect. In in vivo digestibility trials sheep consumed increasing amounts of dried MDG when the level of calcium supplementation was increased. Rations containing fat levels similar to that of MDG should be supplemented with calcium at levels higher than normal requirements of the element.     

The use of chromic oxide as a food marker —a warning

Four mixtures of ground barley and soya bean meal were prepared; the first had no further additive, the second had 10% soya bean oil, the third 0.05% chromic oxide and the fourth both 10% soya bean oil and 0.05% chromic oxide. Each of these mixtures was then dried in three ways: at 30°C in vacuo and at 60 and 100°C in a forceddraught oven. The total fatty acid content and the fatty acid composition of each sample was determined either by direct esterification of the fatty acids with methanolsulphuric acid or by extraction into chloroform-methanol followed by esterification with sodium methoxide. When the mixture containing both oil and chromic oxide was heated at 100°C, about 25% of the polyunsaturated fatty acids were lost when they were directly esterified and about 50% when the fat was first extracted from the mixture. It is concluded that this loss is probably due to oxidation of the polyunsaturated fatty acids by the chromic oxide and that the additional loss observed when the extraction method was used is due to partial insolubilisation of the triglyceride by these oxidised fatty acids.     

Rheological properties of wheat dough supplemented with functional by-products of food processing: Brewer’s spent grain and apple pomace

The physicochemical properties of brewer’s spent grain (BSG) and apple pomace (AP), and their effect on dough rheological properties were investigated. BSG had high protein content and both by-products were found to be high in dietary fibre. The rheological and the pasting properties of dough were significantly altered by the addition of by-products, with the main effects being due to the presence of dietary fibre. The biaxial extensional viscosity was significantly higher for the supplemented doughs; the strain hardening index decreased with increasing the levels of flour substitution. The replacement of wheat flour with the by-products significantly reduced the uniaxial extensibility, while the storage modulus, G″, was found to increase, indicating changes in the structural properties of dough. These changes were reflected in the ability of dough to rise during proofing.     

Availability of essential amino acids from proteins. II.—food proteins

The availability of leucine from L-leucinamide hydrochloride, L-leucyl-glycyl-glycine and glycyl-L-leucine as substrates for leucine aminopeptidase and glycyl-leucine dipeptidase was studied with Streptococcus faecalis, S. zymogenes and Lactobacillus arabinosus. The results indicate that these micro-organisms have their own activity of exopeptidases through which they may utilise amino acids of peptides, released from the proteins by hydrolysis by endopeptidases. The availability of leucine from the proteins of beef muscle, hydrolysed by pepsin, trypsin, pancreatin or papain was also studied. The amount of available leucine found differed according to the enzyme and micro-organism used. Most efficient were pancreatin and papain. The calculated total amount of leucine present in the proteins studied was not found experimentally by digestion with any of these enzymes. Further hydrolysis by leucine aminopeptidase increased the availability of leucine to 84.6-100%. By using leucine aminopeptidase simultaneously with prolidase, complete availability with all micro-organisms was reached. It is suggested that the availability of essential amino acids in the proteins may be determined microbiologically after total enzymic hydrolysis by papain, leucine aminopeptidase and prolidase. By this method the proteins of beef muscle freeze-dried and stored for 4 years, and those of meat bone meal and blood meal were analyzed.     

Sensory and instrumental measurement of food crispness: II — In a high moisture food

Preliminary attempts to compress cylinders of apple tissue under constant loading rate to obtain catastrophic breakdown of the samples were unsuccessful. Puncture and ‘biting’ tests, where the shear component was dominant, yielded some useful results. Highly significant correlations (p < 0·001) were obtained between sensory crispness and sensory hardness and between sensory crispness and most of the physical measurements obtained when using these two tests. The measurements chosen for the regression analysis (equivalent sound level, fracture rate and work done during fracture) were those thought to be of significance in the sensory measurement and included in the definition of crispness.The results of the regression analysis show that both the ‘biting’ and puncture tests produced a number of almost equally-well-fitting equations with the equivalent sound level and the work done during fracture as the dominant variables in predicting sensory crispness in a high moisture food. The regression equations of the ‘biting’ test always tend to give a better prediction of crispness (higher values of R²) than the respective puncture test equations.The values of the maximum sound levels in octave bandwidths over the audible range for the fresh and stored apples show the same broad spectrum, with the stored samples producing, in general, less sound at all frequencies, significantly so for frequencies greater than 3 kHz.     

Studies on the lipids of flour IV.—Factors affecting lipid binding in breadmaking

The binding of specific lipids during the high-speed mixing of doughs and in the resulting bread was studied in relation to mixer atmosphere. the presence of air was found to cause a fall in the linoleic acid content of the triglyceride lipids, an effect apparently related to the reduction in lipid binding. Replacement of the free lipid of flour (the main source of triglyceride linpleate) by extra shortening fat caused a large increase in bound lipid in doughs mixed either in air or in nitrogen, together with the drop in bread quality and volume observed previously. It was concluded that the natural free lipid of flour plays an important part in modern breadmaking processes both in responding to the atmosphere in the dough mixing chamber and in its effect on the binding of shortening triglyceride during dough development.     

Isolation of L-mannitol from ‘Gari’—a processed food from cassava (Manihot esculenta crantz) tubers

‘Gari’, a processed food from cassava (Manihot esculenta Crantz) tubers was extracted with ethanol:water (75:25 v/v). A crystalline compound (m.p. 163°C, yield: 3.1%, 1.1 % w/w of gari) was isolated from the extract of the gari processed by mechanical method and by the traditional method, respectively. A combination of i.r., t.l.c, n.m.r., m.s. and polarimetric analyses was used to identify the crystalline compound as Lmannitol. This compound is believed by the authors to be the same as the one previously detected in cassava tubers as ‘mannit’.     

Evaluation of carrot varieties for production of deep fried carrot chips — II. Sensory aspects

Carrot variety had a significant (P ≤ 0.0005) influence on colour, sweet taste, fruity taste, acid taste, bitter taste, earthy taste, juiciness and crispness, while cultivation site (environmental conditions) had a significant (P ≤ 0.0005) influence on colour, sweet taste, bitter taste, earthy taste, aftertaste, juiciness and crispness. Sensory attributes of raw carrots could predict the quality of carrot chips by means of two factors when PLS has been applied. Factor 1 was explained mainly by cultivation site, but also by variety, while factor 2 was explained by variety.     

Microbiology and amino acid composition of Ogiri — a food condiment from fermented melon seeds

The traditional method for preparing Ogiri is described. Microorganisms associated with the various stages of fermentation were mainly bacteria; the genera frequently isolated are Pediococcus, Proteus, Klebsiella, Escherichia and Bacillus. The morphological and biochemical properties of the isolates are studied in pure cultures. While the temperature remained fairly constant during the fermentation, the pH increased sharply. The predominant amino acids are alanine, lysine and glutamic acid. Arginine and proline are present in low quantities. Threonine is completely absent.     

Evaluation of a system for rating edema in dairy cattle.

Our objective was to evaluate a subjective edema rating system to quantitate edema severity. Edema was evaluated with 20 nulliparous Holstein heifers from 3 wk before their expected calving date until 3 wk postpartum. Severity of udder edema was evaluated independently daily by five people throughout the 68-d experiment; a 10-point rating system (0 = no edema, 10 = severe edema) was used. One of the people developing the scoring system served as the official scorer. The accuracy of the rating system, defined as the closeness of test evaluator scores to official scores, was highest for scores 2 to 8. The precision of the system, identified by the standard error of the mean, was similar for each score in the rating system. The largest disagreement between official and test evaluator scores was evident postpartum. The large number of defined points in this rating system and the similarity between official and test scores in this study indicate the usefulness of this tool to evaluate precisely the severity of edema in dairy cattle.     

Chemical Evaluation of Musa ‘Bhimkol’ as a Baby Food

The edible pulp of Musa ‘Bhimkol’ was analysed for certain organic compounds and mineral nutrients at two stages of development of the fruit to evaluate it as a baby food. Energy value and carbohydrate concentration increased substantially as the fruit ripened so that 16.8% of the energy requirement (recommended daily allowance, RDA) for six-month-old infants would be met by 100 g of the fresh pulp. Although vitamin C content decreased at maturation, 7% of the RDA would be provided by 100 g fresh pulp. The fruit was found to be very rich in macro- and micronutrients, and 100% of the six-month infants RDA for K, Mn, Zn and Se would be satisfied with 100 g of fresh pulp. This amount of pulp would also provide 86%, 57%, 24% and 12% respectively of the Mg, Cu, Fe and P RDA. P and Mg were found to be more highly concentrated in the ripe than in the unripe fruit whereas the reverse was the case for Ca and Se. Aspartic acid, glutamic acid and leucine were the major amino acids in the ripe fruit and respectively constituted 13.1, 12.5 and 7.9%, of the total. The concentration of essential and non-essential amino acids was much higher than that in a commercial banana. Twelve of the 17 amino acids analysed were more concentrated in the mature compared with the green fruit, and 11 of these were an order of magnitude higher than in M paradisiaca L banana. The results of the present study demonstrate that Musa ‘Bhimkol’ is a nutritious baby food.     

γ‐Glu‐Met synthesised using a bacterial glutaminase as a potential inhibitor of dipeptidyl peptidase IV

This study describes γ‐glutamyl dipeptides as competitive inhibitors of dipeptidyl peptidase‐IV (DPP‐IV), and the feasible synthesis of γ‐Glu‐Met through transpeptidation catalysed by a commercial glutaminase of Bacillus amyloliquefaciens. γ‐Glu‐Met, γ‐Glu‐Leu, γ‐Glu‐Phe, γ‐Glu‐Trp or γ‐Glu‐Tyr exhibited a competitive inhibitory effect on DPP‐IV. The yield of γ‐Glu‐Met was 26.16% under optimised conditions: 200 mm Gln, 20 mm Met, 0.1 U mL^?1 enzyme, pH 9.0, 37 °C and reaction time 3 h. For the first time, the side products containing characteristic sequences, that is poly‐γ‐glutamyl short chains with a terminal Met residue (γ‐Glu‐γ‐Glu‐Met and γ‐Glu‐γ‐Glu‐γ‐Glu‐Met) were identified. The superiority of the commercial glutaminase in the synthesis of DPP‐IV‐inhibitory peptides can enable the application of this novel process for manufacturing γ‐glutamyl‐peptides as potential functional ingredients in the type 2 diabetic diet.     

Chemical constitution and activity of bipyridylium herbicides: IV.—Diquaternary salts of methyl substituted 1,10-phenanthrolines

Eight bridged diquaternary salts of methyl substituted 1,10-phenanthrolines have been prepared. They are reduced in aqueous solution to radical cations at about the same potential as diquat by a one electron transfer which is largely reversed by air. in herbicidal tests they showed slight activity at a rate equivalent to 8 lb/acre. Their relatively poor phytotoxic properties are considered to be due to their large size which hinders their reaching the site of biological action of the bipyridylium herbicides.     

Evaluation of cheddar cheese as a food carrier for delivery of a probiotic strain to the gastrointestinal tract.

Cheddar cheese was evaluated as a food carrier for the delivery of viable microorganisms of Enterococcus faecium (Fargo 688; Quest Int., Naarden, The Netherlands) to the gastrointestinal tract. This strain had previously been shown to possess properties required of a probiotic microorganism including the ability to relieve irritable bowel syndrome. The strain was found to survive to high numbers in Cheddar cheese during ripening at 8 degrees C for 15 mo (4 x 10(8) cfu/g) and in yogurt during storage at 4 degrees C for 21 d (4 x 10(7) cfu/g). In an in vitro model system, Cheddar cheese was found to have a greater protective effect than yogurt upon exposure of the probiotic culture to porcine gastric juice at pH 2. Subsequently, a feeding trial involving 8 pigs per group was performed in which a rifampicin-resistant variant of the probiotic strain was fed for 21 d at a mean daily intake of 1.3 x 10(10) cfu/d from Cheddar cheese or 3.7 x 10(9) cfu/d from yogurt. During the feeding period, Cheddar cheese yielded a significantly higher mean fecal probiotic count (2 x 10(6) cfu/g of feces) than did yogurt (5.2 x 10(5) cfu/g of feces). These data indicate that mature Cheddar cheese compares very favorably with fresh yogurt as a delivery system for viable probiotic microorganisms to the gastrointestinal tract.     

Evaluation of calcium lignosulfonate-treated soybean meal as a source of rumen protected protein for dairy cattle

Four Holstein cows fitted with ruminal, duodenal, and ileal cannulae were used in a 4 x 4 Latin square design to measure ruminal protein degradation and small intestinal digestion of diets containing untreated soybean meal or soybean meal treated with heat and either water, xylose, or calcium lignosulfonate. Diets consisting of 40% corn silage, 10% alfalfa cubes, and 50% grain mix, and averaging 16.8% crude protein (DM basis) were fed four times daily. Approximately 50% of the total dietary protein was supplied by the respective soybean meal source. Ruminal protein degradation was 70.6, 69.6, 55.8, and 53.7% for diets containing untreated soybean meal, water-soybean meal, xylose-soybean meal, and calcium lignosulfonate-soybean meal, respectively. Duodenal non-NH3 N flow (g/d) and absorption of non-NH3 N (g/d) in the small intestine were generally not affected by treatment. Duodenal bacterial N flow (g/d) was lower with xylose-soybean meal and lignosulfonate-soybean meal than with untreated soybean meal. Treatment of soybean meal with xylose or calcium lignosulfonate was successful in decreasing ruminal protein degradation. However, it may be necessary to include a source of readily fermentable N in diets that contain protected proteins in order to supply adequate NH3 N for microbial protein synthesis.