The preovulatory follicle of the domestic hen is almost certainly a steroid-producing structure (see Shahabi, Norton & Nalbandov, 1975). However (Gilbert, 1971 ). A cut, about 2 cm long, was made with a scalpel approximately along the line of the stigma, though the exact position is not critical. This step must be carried out quickly, with one sweeping stroke, and it should be completed before much escape of yolk occurs. Scissors may be used instead of a scalpel but they were found to be less satisfactory because there was a tendency for a point to penetrate too deeply into the yolk mass. Immediately after it had been cut the follicle was inverted over a suitable dish containing an aqueous medium and the follicular contents (yolk, perivitelline layer, granulosa and basal lamina) (Gilbert, 1971) were allowed to fall into the medium. The choice of medium depended on the purpose for which the granulosa cells were being harvested.If the operation has been done correctly, the entire theca (Text- fig. 1, PI. 1, Fig. lb) remains held in the forceps, without contamination by yolk or granulosa material, and it can be used for studies of thecal activity. The yolk, covered by the perivitelline layer, the granulosa layer and the basal lamina (Text- fig. 1, PL 1, Fig. 3), settles as an almost undisturbed sphere on the floor of the vessel. The split occurs at a position different from that occurring during ovulation when the granulosa cells and the basal lamina remain with the theca (PI. 1, Fig. la).Removal of the granulosa layer, together with its associated basal lamina and perivitelline layer, from the yolk was carried out under a low-power lens or dissecting microscope with a black back¬ ground. The cut ends of the composite membrane surrounding the yolk were located, grasped with fine dissecting forceps and gently pulled away from the yolk thereby everting the membrane over the surface of the yolk: this was made easier by using the yolk as a mass to pull against. Care was taken to protect the yolk from undue disturbance because yolk material dispersed throughout the medium prevented clear observation and caused unnecessary contamination of the preparation. It

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Abstract:The hulls and cotyledons from three Western Australian cultivars (Gungurru, Yorrel and Danja) of Lupinus angustfolius, all of low alkaloid content, were analysed separately for their carbohydrate content and composition.Only minor differences in composition between these three cultivars were observed. More notably, the cotyledons of all the cultivars contained levels of non-starch polysaccharides (NSP), ranging from 290 to 310 g kg-' dry weight considerably higher than had been measured previously in cultivars of this species. Galactose, arabinose and uronic acid residues accounted for approximately 67%, 13% and 10 %, respectively, of the cotyledon NSP. Although only a small proportion of the cotyledon NSP is soluble, a much larger proportion could be extracted with hot EDTA treatment. The oligosaccharide content of the cotyledons ranged from 74 to 80 g kg-' dry weight. Cotyledons had very low contents of cellulose, lignin and starch. Hulls consisted predominantly of NSP, with values ranging from 856 to 891 g kg-' dry weight. Glucose, xylose, uronic acids and arabinose were the principal sugar residues present reflecting the compositions of the major constituent polysaccharides, cellulose, hemicelluloses and pectins. Only low levels of lignin were measured in hulls. Cotyledon NSP and hulls from these cultivars may have considerable value as sources of dietary fibre in the human diet.

Aims: To study the effects of amylomaize starch and modified (carboxymethylated and acetylated) amylomaize starches on the composition of colonic bacteria and the production of volatile fatty acids, in mice. Methods and Results: Balb ⁄ c mice were fed with experimental diets containing various amount of amylomaize and modified amylomaize starches. Colonic bacterial populations and short-chain fatty acids were monitored. Results showed that the increases in indigenous bifidobacteria were detected in mice fed all starches tested; however, the highest numbers were observed in the group fed with 40% unmodified amylomaize starch. The starch type influenced the populations of indigenous Lactobacillus, Bacteroides and coliforms. High Lactobacillus numbers were achieved in the colon of mice fed with high concentration of amylomaize starch. Acetylated amylomaize starch significantly reduced the population of coliforms. In addition, orally dosed amylomaize utilizing bifidobacteria reached their highest levels when fed together with amylomaize or carboxymethylated amylomaize starch and in both cases butyrate levels were markedly increased. Conclusions: These results indicate that different amylomaize starches could generate desirable variation in gut microflora and that particular starches may be used to selectively modify gut function. Significance and Impact of Study: Amylomaize starch appeared to enhance the desirable composition of colonic bacteria in mice, and suggested it possessed the potential prebiotic properties. Therefore, resistant starch and its chemical derivatives may exert beneficial impacts to the human colon.

The possibility of using high amylose maize starch granules as a delivery system for probiotic bacteria has been investigated using Bifidobacterium spp. Lafti TM 8B and Lafti TM 13B which were isolated from a healthy human. The Bifidobacterium cells were able to adhere to the amylomaize starch granules and were also able to hydrolyse the starch during growth. Initially, in vitro studies were carried out by studying the survival of strains Bifidobacterium Lafti TM 8B and Lafti TM 13B when exposed to pH 2·3, 3·5 and 6·5 as well as 0·03 and 0·05% w/v bile acids. Both strains were grown either in the absence or presence of high amylose maize starch granules, then mixed with the high amylose maize starch granules and exposed to acidic buffers or bile acid solutions. It was shown that growth in and the presence of high amylose maize starch granules led to enhanced survival of strains Lafti TM 8B and Lafti TM 13B. Subsequently, survival in vivo was monitored by measuring the faecal level of Bifidobacterium Lafti TM 8B after oral administration of the strain to mice. A sixfold better recovery of strain Lafti TM 8B from mice faeces after oral dosage was noted for cells grown in amylose-containing medium compared with controls. It was concluded that high amylose maize starch granules contributed to enhanced survival of Bifidobacterium sp. Lafti TM 8B and Lafti TM 13B.