The nutritional quality of some improved varieties of chick peas (Cicer arietinum), mash beans (Phaseolus mungo), mung beans (Phaseoius aureus) and cow peas ( Vigna sinensis), grown in Pakistan, was measured chemically (including amino acid analyses) and biologically in N-balance experiments with growing rats. Lysine and total sulphur amino acids were lowered in varieties with a higher content of protein. The true protein digestibility (TD), biological value (BV) and net protein utilisation (NPU) of different varieties of chick peas, mung beans and cow peas varied between 85-89, 83-85 and 87-92%, 62-69, 5 4 5 6 and 55-59 % and 55-60,4548 and 50-51 %,respectively. The TD of protein was highest (89%) in chick peas, 6560 having a higher protein content (29.4 %) while its BV was lowest (62 %) as compared to the other varieties of chick peas. There was a significant correlation (r=0.97) between BV and the total sulphur containing amino acids and BV could be predicted from the regression equation: BV (%)= 33.03 + 10.56 x methionine+ cystine (g per 16 g N). This indicates that methionhe+ cystine are the first limiting amino acids in these varieties. Tannin content does not seem to affect the TD of mash and mung beans.

Denmark. Seeds ofEruca vesicaria (L.) Cav. em. Thell. ssp. sutiva Thell. were obtained from (RAHMAN et JI. 1986). Seeds ot' Crumbc riruritimu L. were collected troni the natural sites in Denmark. Seeds ofEruca vesicaria (L.) Cav. em. Thell. ssp. sativa Thell. were obtained from U S . and multiplied by growing of the plants at Hojbakkegaard, Taastrup, Denmark. Seeds of Iberis amara L., Tropaeolum majm L. cv. Grandiflorum and Cheiruntus cheiri L. were purchased from J. E. Ohlsens Enke A/S, Taastrup, Denmark. Seeds of Sinapis alba L. were obtained from Trifolium-Silo A/S, Taastrup, Denmark. General methods and instrumentationMethods and equipment used for paper chromatography (PC), high voltage electrophoresis (HVE), 'H-and I3C-NMR have been described previously (OLSEN and SORENSEN 1980). The glucosinolate analysis was performed on intact glucosinolates and desulfoglucosinolates using reversed phase high performance liquid chromatography (HPLC) as described elesewhere (BJERG and SORENSEN 1987a). Isolation of intact glucosinolatesThe techniques used for isolation and characterization of the glucosinolates have followed the principles described previously (BJERG and S~R E N S E N 1987 b). Seeds (100 g) were homogenized with an Ultra-Turrax homogenizer in boiling methanol: water (7: 3; 0.6 1) cooled and filtered. The residue was treated twice in this way and the combined filtrates were concentrated in vacuum to about 30 ml and extracted with 2 x 30 ml chloroform. After centrifugation the water phase was transferred to a column ofAmberlite IR-120 (H+; 5 x 40 cm) connected in series to a column ofEcteola-cellulose (AcO-; 5 x 100 cm). The two columns were flushed with water (2 1) after which the glucosinolates were eluted from the Ecteola column with 1 M pyridine. Glucosinolate containing fractions were pooled, concentrated and transferred to a column ofAmberlite IR-120 (K+; 5 x 40 cm). The column was flushed with water and the fractions with potassium salts of the glucosinolates were take to dryness before final purification on Sephadex, Polyclar AT and/or SPE columns as described elsewhere (BJERG and SORENSEN 1987 b). The purity of the isolated glucosinolates was determined by the previously described methods (BJERG and SORENSEN 1987b) including PC, HVE, HPLC, 'Hand 13C-NMR. In this way seeds of C. maritima (83 g) afforded epiprogoitrin (4.6 9); seeds of E. vesicaria (100 g) afforded glucoraphanin (2.8 g), glucoerucin and lower amounts of some other glucosinolates; seeds of B. cumpestris cv. Sampad (200 g) afforded gluconapin (5.9 8); seeds of I. urnara (200 g) afforded glucoiberin (12 g); seeds of T. majzs cv. grandiflorum (200 g) afforded glucotropaeolin (8 g); seeds of C. cheiri (200 g) afforded glucocheirolin (10 8).The isolated crystalline glucosinolates were stored under vacuum in a desiccator until use. Preparation of myrosinasesThe thioglucoside glucohydrolase EC 3.2.3.1 (myronisases) were extracted from seeds of Sinapis ulba L. according to the procedure of BILLE et al. (1983 b), with centrifugations carried...

Zusammenfassung Antinutritive und toxische Wirkungen von Glucosinolaten (± Myrosinasen) bei Ratten. 1. Der Einfluß auf die Protein‐Verwertung und die Organgewichte Relativ große Mengen von verschiedenen Glucosinolaten wurden aus unterschiedlichem Pflanzenmaterial isoliert. Die Methoden zur Isolierung und Separation der Glucosinolate basierten auf der Säulenchromatographietechnik. Die Glucosinolate wurden abschließend in Kaliumsalze übergeführt und aus dem Wasser rekristallisiert. Myrosinasen (Thioglucosid Glucohydrolase EC 3.2.3.1.), von Bestandteilen mit niedrigem Molekulargewichten befreit, wurden aus Samen von Sinapis alba L. in Pulverform isoliert, und deren Enzymaktivitäten mit Allylglucosinolat (Sinigrin) als Substrat bestimmt. Stickstoffbilanzversuche wurden mit wachsenden Ratten vorgenommen, die mit einem standardisierten Futter, aus autoklavierter Kartoffelstarke, Kasein + Methionin, Sojaöl, Mineralstoffen und Vitaminen bestehend, gefuttert wurden. Die isolierten Glucosinolate wurden einzeln in verschiedenen Mengen dem Standardfutter beigemischt. Bei einer Diät wurden ebenfalls Myrosinasen zugefügt (0,2, 1,0, 5,0 und 1,0 mg/g Trockensubstanz + Myrosinasen). Ansonsten enthielt dieses Futter keine anderen Bestandteile mit niedrigen Molekulargewichten von Kreuzblütlern. Die Futterverwertung, die Proteinausnutzung und die Organgewichte der Ratten wurden bestimmt. Die Ergebnisse zeigten, daß besonders die höchsten Konzentrationen (5 mg/g Trockensubstanz) der intakten Glucosinolate und der Glucosinolate + Myrosinasen Probleme in bezug auf die Schmackhaftigkeit des Futters verursachen konnten, außerdem die Proteinausnutzung reduzieren und die Größe der verschiedenen inneren Organe beeinflussen konnten. Es soll betont werden, daß intakte Glucosinolate (ohne Myrosinasen) signifikante negative Ernährungs‐ sowie Giftwirkungen verursachen können. Des weiteren können die unterschiedlichen Glucosinolate verschiedene Wirkungen zeigen, wenn auch die Beobachtungen teilweise einheitlich waren. Die deutlichste Wirkung wurde dort festgestellt, wo 2‐Hydroxybut‐3‐enylgluco‐sinolat (Progoitrin) im Futter vorhanden war. Bei den niedrigen Glucosinolatniveaus ließ sich kaum ein Einfluß auf die Proteinausnutzung feststellen, wogegen die Gewichte der Organe sogar bei den niedrigsten Niveaus beeinflußt werden konnten. Glucosinolatkonzentrationen im Futter, die dem Niveau in den glucosinolatarmen Rapssorten entsprachen (0,2‐1,0 mg/g Trockensubstanz), in denen Raps als einzige Proteinquelle benutzt wurde, hatten nur geringen oder gar keinen physiologischen Einfluß bei wachsenden Ratten innerhalb der betreffenden Versuchsperiode. Die Ergebnisse demonstrieren, daß es möglich ist, glucosinolatarme Rapssorten anzubauen, bei denen sowohl die totale Menge als das relative Verhältnis der verschiedenen Glucosinolate, sich auf einem ernährungsphysiologisch akzeptablen Niveau befinden. Die Ergebnisse zeigen, daß die Myrosinasen den Gift‐ und den negativen Ernährungseffekt von einigen Glucosinolaten verschärfen. Um die Probleme zu verhindern, di...

1. Two series of balance experiments were performed with growing rats to test the effect of black tea, green tea, coffee and cocoa on protein and energy utilization. In Expt 1 soya-bean meal was fed as a basal diet and supplemented with freeze-dried materials from 11 black tea, green tea or coffee/500 g dry matter. Cocoa powder, corresponding to 11 of the beverage, was also added to the basal diet. In Expt 2 the procedure was repeated with a barley-based diet.2. In both experiments both tea varieties and coffee had significantly negative effects on true protein digestibility and biological value, while digestible energy was only slightly affected in the barley-based diet. Cocoa had no effect on protein or energy utilization in either soya-bean meal or barley diets, although the protein in cocoa powder was completely indigestible.3. As the tannin concentration in both tea varieties and coffee was very high it is assumed that the observed deleterious effects might, in part, be explained by anti-nutritional effects of tannin.4. The strongest deleterious effect was recorded for black tea.