No abstract

The effect of "indigestible" polysaccharides fed at the 10% level in a semi-synthetic diet on absorption of Ca, Fe, Zn, Cu, Cr and Co, on weight gain and on fecal dry matter excretion was studied over a period of 8 days in five groups of 12 weanling male rats each and compared to a control group. Carrageenan (C) and agar-agar (AA) reduced absorption of all minerals tested, Na-alginate (NA-A) decreased Fe-, Cr- and Co-absorption, carob bean gum (CBG) and gum guar (GG) interfered with the absorption of Zn, Cr, Cu and Co. In a second study the long-term effect of GG and AA-ingestion at the 10% dietary level on mineral absorption was investigated during three 4-day balance periods of a 21-week feeding trial in 24 young rats. Mineral content of rat carcasses, assayed at the termination of the experimental period, did not reveal any significant differences between controls and animals fed AA or GG, suggesting that the rat is able to compensate for the increased fecal losses, presumably by reduced urinary losses. Ingestion of AA, C or Na-A resulted in a marked increase of fecal dry matter, indicating that hardly any of these substances were degraded, whereas a considerable portion of GG and CBG was metabolized, presumably due to the action of intestinal bacteria.

No abstract

The changes in nutrients during the germination of wheat, mung beans and chickpeas were investigated. Germination was performed under conditions commonly used in the household. The amount of water taken up during 4 days of germination varied from 159 g/100 g (chickpeas) to 450 g/100 g (mung beans). For all three seeds losses of dry matter and carbohydrates were observed. In wheat and mung beans, phytic acid was partially hydrolyzed. In mung beans, the total fat content decreased. Increases in the content of polyunsaturated fatty acids in wheat and of dietary fibre in wheat and mung beans were noted. At a constant level of crude protein, a measurable rise in limiting amino acids was observed in wheat and mung beans. Frequent watering during germination caused losses of Fe, between 9% and 21%, K (27% in chickpeas) and Cu (17% in chickpeas). Except for vitamin B6 in both legumes and vitamin B1 in chickpeas, accumulation of the vitamins under investigation (B1, B2, B6, C, E) was noted. Owing to these changes during germination, the nutritional value of the three seeds has been improved to various extents, most distinctly in wheat and least noticeably in chickpeas. Compared with other vegetables, sprouted seeds can be considered a valuable addition to the diet.

The effect of five indigestible polysaccharides (IP) of different origin and chemical structure on N balance and dry matter digestibility was studied in growing rats. The diets contained 10% of gum guar (GG), carob bean gum (CBG), Na-alginate (Na-A), agar-agar (AA) or carrageenan (C), respectively. Dry matter digestibility and apparent protein digestibility were significantly decreased below control values by all 5 IP. N retention was significantly lower after ingestion of AA or C. In the rats receiving GG, CBG or Na-A urinary N excretion was reduced, thus compensating for increased fecal N losses by these animals. The different effects of the 5 substances on N balance are attributed to their partial breakdown through the action of intestinal microflora and/or their ability to partially inhibit the activity of proteolytic enzymes in the gastrointestinal tract. Trypsin inhibition in vitro was observed for C only. Suitability of the various IP as bulking agents in reducing diets is discussed.