1. The available methionine and cysteine contents of proteins were determined by chemical methods after preliminary enzymic hydrolysis.2. The values for the available methionine and cysteine contents of pure proteins (casein and bovine serum albumin) estimated by chemical methods were similar to those for the total content determined by the method of Moore, Spackman & Stein (1958).3. Reductions of 15 and 11% respectively, when compared with unprocessed samples, were found in the available methionine contents of sweetened and unsweetened, condensed milks; of roller-dried milk and whey powders, and of mackerel sterilized at 126°, the reductions were 22, 14 and 19% respectively.4. The available cysteine content of sweetened, condensed milk was reduced by about 32%, whereas for mackerel sterilized at 115 and 126° it was reduced by 64 and 75% respectively.5. The contents of total sulphur amino acids for these food products did not differ from those for the unprocessed samples.6. Values obtained for available S amino acid contents by rat bioassay confirmed the results of the in vitro estimations.

Microdochium nivale (Fusarium nivale) was found to be frequently occuring in Poland pathogen of small grain cereals heads, causing symptoms similar to those observed after infection ofFusarium species. In consecutive years since 1985 till 1989 the following percentage of wheat and rye ears infected withM. Nivale and withFusarium head blight symptoms was found: 34%, 21%, 42%, 9%, 46% (wheat) and 57%, 43%, 65%, 4%, 47% (rye) heads.However, in naturally infected rye and wheat samples (kernels and chaff), we did not detect toxins usually present in samples infected with fungi of genusFusarium - such as deoxynivalenol and derivatives. TypicalFusarium trichothecene metabolites were also not present in cultures of 11M. nivale strains, growing 3-5 weeks on rice (45% water content) at 20°C. Cultures of two typical isolates on wheat grain (strain KF 1124) and on rice (KF 245) were found to be non toxic to broiler chickens when present in amount 20-40% in their diet. It can be concluded thatM. nivale (F. nivale) representatives in Poland did not produce toxic metabolites neither under laboratory condition nor after cereal ears infection under field conditions.

Six pigs of initial weight 40 +/- 1.7 kg with a T-piece cannula fitted at the terminal ileum were given diets composed of 96.3% of rye, barley or triticum grains ground to pass the 2.6 mm mesh, 3.3% mineral and vitamin mixture and 0.4% Cr2O3. Each diet was given to all pigs in a Latin square design, and faeces and ileal digesta were collected on 7, 8, 9 and 10, 11 and 12 day of feeding each diet, respectively. The grains varied widely in the content of pentosans, polyuroids, beta-glucan and monosaccharides. The antitrypsin activities were 0.84, 2.73 and 1.62 TUI/g in barley, rye and triticum, respectively. Ileal and faecal apparent digestibilities of nitrogen and amino acids were higher (P less than or equal to 0.01) in Triticum than in barley and rye. The digestibility of carbohydrates (pentosans, beta-glucan, polyuroids and non-structural carbohydrates) were lower in pigs fed a rye diet than of those fed a Triticum diet. The results are discussed with respect of the role to non starch polysaccharides, especially pentosans in digestibility of nitrogen and energy in animals receiving a rye diet.

I. The influence of temperature, moisture content and the presence of glucose on the level of available methionine and cysteine in casein was studied.2. Differences between total and available methionine and cysteine contents of heated casein (90" for 24 h) were determined by an in vitro method. The maximum losses in total and available methionine content were 22 and 51 yo respectively. The losses in total and available cysteine content were 24 and IOO 76 respectively. 3.The results indicated that for heated casein the release of amino acids by proteolytic enzymes was less complete than for native casein. 4.The results of rat growth assays suggested that diets containing oxidized casein are less well utilized by rats than those containing native casein. The decrease in body-weight of rats receiving the diets containing oxidized casein could be counteracted by the addition of methionine and 20 g unoxidized caseinlkg diet.5. There was a lower level of some available amino acids (determined after enzymic hydrolysis using pancreatopeptidase E (EC 3 .4.4.7), leucine aminopeptidase (EC 3 .4. I . I) and prolidase (EC 3.4.3.7)), including those essential for the rat, in oxidized casein as compared with native casein.6. Cysteic acid, in oxidized casein, probably makes impossible the utilization of the amino acids in its neighbourhood. 7. From the differences in die available amino acid contents of the native, oxidized and heated casein it was concluded that the oxidation of casein causes the formation of complexes in the polypeptide chain, resistant to enzymic hydrolysis, but to a much lesser extent than does heating.The effects of high temperatures and the presence of reducing sugars during processing are the most common reasons for the reduction in the biological value of proteins of food products. This reduction is only to a small extent correlated with destruction of amino acids, and is mainly the result of a decrease in the available amino acid content associated with the formation of polypeptide fragments resistant to the action of proteolytic enzymes (Miller, Hartley & Thomas, 1965).The changes which occur in proteins as a result of technological processing are generally measured by methods based on changes in available lysine content, as this amino acid is very easy to determine both chemically and biologically.It is known that the decrease in available lysine in proteins subjected to thermal processing is due to the blocking of e-amino groups, which occurs both in the presence and absence of reducing sugars, although the mechanism in the latter instance is not known.Some workers have suggested that in the absence of carbonyl components character- Although the available amino acid content can be determined microbiologically, this method cannot be used to study the mechanism of changes occurring in the other amino acids in proteins, which lead to a decrease in biological value. Therefore because of procedural difficulties little is known about the effects of processing on the formation, in proteins, of forms of a...

Ileal and faecal excretion of the non-cellulosic components of the dietary fibre was studied in cannulated pigs fed wheat (control) and two inbred lines of rye with low and high (3.8% and 5.6%) level of soluble dietary fiber (SDF). As compared to the intake,the major fiber components arabinose and xylose were excreted in the ileal digesta in 81.9 and 81.8% after feeding with low-SDF rye and in 79.3 and 79.5% when wheat was fed to the animals. Significantly lower fiber degradation was observed after feeding pigs with high-SDF rye; the recovered arabinose and xylose amounted to 93.3 and 90.6%. It was also found that in the small intestine both sugars disappeared to the similar extent. Unlike in the ileal digesta, in faeces the lowest excretion of arabinose and xylose was observed after feeding pigs with high SDF rye (44.0 and 22.7%), the highest when wheat was fed (52.3 and 32.1%) and intermediate for low-SDF rye (49.2% and 28.3%). Whatever the diet, xylose was disappearing in a higher proportion than arabinose. Glucose absorption in the small intestine was notably influenced by the diets; more was found in the digesta after feeding ryes (14.5 and 11.2%) than wheat (6.6% of the intake). This can be explained by different viscosity of the cereals. It was estimated that glucose recovered in the digesta originated in about 69% from starch. Only trace amounts of glucose were found in faeces.

No abstract

The content of available sulphur amino acids in food proteins has been determined by the chemical methods after preliminary digestion of proteins with pancreatin. The values for the available methionine and cysteine contents of pure protein (casein, bovine serum albumin) and protein of food (fresh milk, whey, mackerel, beef, pork, wheat flour) estimated by the specific chemical methods were similar to those for the total content determined by the method of Moore et al. (6). Differences between total and available methionine and cysteine contents of heated casein were found.

Content of dietary fibre (DF) as well as content and composition of non-starch polysaccharides (NSP) were evaluated in disomic wheat-rye addition lines and octoploid triticale compared to their parental species -wheat (Grana) and rye (Dafikowskie Z1ote). Large variation in the contents of NSP and DF were observed in the wheat-rye addition lines, especially in the soluble fractions. The double addition of rye chromosomes led to important transgression effects on content and composition of DF in wheat grain. Chromosomes 2R and 5R increased SDF content above the rye level, whereas the 3RS arm decreased SDF content below the wheat level. The octoploid triticale demonstrated the highest content of total arabinoxylan (AX), exceeding that of rye, while the double addition of chromosomes 4R, 6R and 6RL had an impact on high expression, comparable to that of rye content of total AX in wheat grain. Chromosomes 2R and 5R notably increased the proportion of soluble non-cellulosic glucose in the NSP fraction, in contrast to the rest of wheat-rye addition lines, octopioid triticale, wheat and rye, where AX was found to be predominant among NSP constituents. The effects of single chromosome pairs on content and composition of NSP proved to be higher than the effect of the whole rye genome in octoploid triticale. The most remarkable effect, especially considering the direction of changes, was of a 3R chromosome short arm addition. The obtained data might be of interest in breeding rye or triticale with lower viscous AX content as well as rich in soluble non-starch glucose polymers, regarded as a corrective factor in modern diseases.