Abstract:The mineral, total amino acid, and sterol compositions of pollen collected by Apis mellifera L. were compared with the pollen of a plant consumed by Bombus terrestris (L.): Arbutus unedo L. This plant provides the predominant food resource for the main autumn generation of B. terrestris in southern France. Honey bees also forage on this plant, although only for nectar. The mineral composition of 30 pollen samples collected by honey bees is close to the presently known requirements of A. mellifera, except for Cu and Mn, which are substantially lower. The total amino acid mean composition of a set of 54 pollen samples fits the basic requirements of honey bees except for valine, isoleucine, and methionine, which are present in lower concentrations in all the samples. For pollen of A. unedo, the amino acid balance is not very different from that of the survey. The main sterolic component in pollen of A. unedo, β-sitosterol, is known to have antifeedant effects on A. mellifera. Honey bees cannot dealkylate C 29 sterols like β-sitosterol or 85-avenasterol to obtain C 27 cholesterol and ecdysteroids. Because these phytosterols as well as cholesterol are nearly absent from pollen of A. unedo, the metabolic capabilities of Apis seem unadapted to this plant. On the contrary, pollen of A. unedo is freely consumed by B. terrestris, which develops huge autumn populations solely on this food. These data indicate that the sterolic metabolisms of B. terrestris and A. mellifera differ, allowing separation in foraging activity.

The influence of coarse milling on the distribution of the protein jiactions in the particles was studied. The profile in proteins was the same for the diferent classes as that for the whole seed. The second part of the work was devoted to the determination of the amino acid composition of the different nitrogenous jiactions.Pea seeds (Pisum sativum L) are mostly used in pig feed because of their low content of antinutritional factors and their high nutritive value. Pea proteins are, however, deficient in Scontaining amino acids (methionine and cystine) and in tryptophan (Mosse et all987). Although pea albumins are richer in essential amino acids (AA) than globulins, no data are available about the AA profile of the insoluble proteins and the non-protein material of pea seed. As the protein fractions do not have the same nutritive value, milling can accentuate this difference in some feeds, such as cereals, because the distribution of the proteins in the seed is heterogeneous and the different particles do not have the same hardness (Taverner et a1 1981). Furthermore, Horvath et a1 (1989) have shown recently that the protein content and some functional properties of pin-milled and airclassified pea flours depend on the particle size distribution. The milling of peas intended for animal feed is coarser, and it is not known if coarse milling modifies the distribution of the protein fractions in the particles. This paper addresses this problem.A sample of peas (cv Solara) was hammermilled through a 3-mm screen with a hammer mill commonly used for pig nutrition. The sieve analysis was performed with a vibratory sieve shaker (Analysette 3, Fritsch, Idar-Obersbein, FRG). The different size fractions were passed through the 0.5-mm screen of a Pulverisette 14 (Fritsch). The procedures of extraction and quantitation of the protein fractions have been described by Gueguen and Barbot (1988). N was analysed according to the Kjeldahl method. The AA compositions were determined using ion-exchange chromatography. Performic acid treatment was used to oxidise methionine and cystine before hydrolysis. Tryptophan was determined by gel filtration

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