As the search for alternative sources of food to alleviate hunger continues, this study was undertaken to determine the fat content and the fatty acid composition of 15 lesserknown wild tropical seeds gathered in Nigeria. Results were contrasted with five tropical soybean varieties (Glycine max). The fat content varies from less than 1% (Pterocarpus santalinoides, Daniellia ogea) to 59% (Entandrophragma angolense). The fatty acid composition of most of the wild and mostly leguminous seeds differed considerably, compared to the composition of tropical soybeans. The oil of Adansonia digitata, Prosopis africana, Afzelia lebbeck, Enterolobium cyclocarpium, and Sesbania pachycarpa contained high proportions of linoleic and oleic acid as well as palmitic and linolenic acid. Seeds of Milletia thonningii, Lonchocarpus sericeus, and S. pachycarpa were much higher in linolenic acid and relatively poor in linoleic acid, compared to soybeans. The content of saturated fatty acids was higher than that of soybeans, resulting in lower polyunsaturated/saturated (P/S) ratios (0.83-2.12) than observed in soybeans (P/S = 3.4), with the exception of the composition of S. pachycarpa (P/S = 3.15). Some of these less familiar wild seeds could be used as sources for industrial or edible oils, provided that possible toxic constituents could be removed.

The influence of acylation on surface functional properties, solubility and heat-induced aggregation of the low-molecular weight basic protein fraction (napin) from rapeseed was studied. While the native protein was soluble over the whole pH-range, the exhaustively acetylated one became precipitable in the weakly acidic range. Acetylation of 70-80% of the protein amino groups caused a stabilizing against heat-induced aggregation. The native protein had a high foam capacity and stability which were only slightly changed after acylation. Decreasing volume specific work in the order native>acetylated > succinylated protein pointed, however, to an improved foamability of acylated napin. Succinylation increased the interfacial tension on the oil/water interface, while acetylation gave both an increasing and a decreasing effect depending on the degree of modification. The emulsifiying capacity decreased after acylation in the order native > acetylated > succinylated.In the preceding paper [ 11 a report was given on chemical and physico-chemical properties of the acetylated low-molecular weight protein fraction from rapeseed. The latter represent highly basic albumin-like proteins and has been called napin [2 -41. This paper is concerned with surface functional properties as well as solubility and heat-induced aggregation of acetylated napin. Surface functional properties of succinylated napin were studied for comparison, too. Materials and metbods Protein preparation and modjkationNapin was extracted from defatted rapeseed flour (low erucic acid variety "Marinus", harvested 1985), isolated and modified as described previously [l]. The succinylation of the protein was described in [5]. Solubility profire and heat-induced aggregationThe pH-dependent solubility was studied by means of turbidimetric titration with hydrochloric acid (0.01 N) from pH 8.0 to pH 2.0 and back titration to pH 8.0 with sodium hydroxide solution (0.1 -0.01 N). The protein concentration was 7.5 x g/l. A spectral colonmeter type Spekol (Carl Zeiss Jena/FRG) was used. The measurement was performed in a I cm cell at h = 420 nm.

Wer sieh mit den Ursachen des Ekzems eingehender beseh~ftigt hat, wird immer wieder finden, dal] auch heute noeh die Frage ungekl~rt ist: Ist das Ekzem eine loka]e, stets und vorzugsweise extern bedingte Hautentziindung oder ist d~s Ekzem der Ausflul] und die Folge einer internen StSrung. Die Antwort ist so versehieden wie mSglich. Die einen erkl/~ren das Ekzem als eine dureh /~uBere Sch~tdlichkeiten bedingte Dermatitis die anderen vertreten den entgegengesetzten Standpunkt, daI3 das Ekzem eine Hautentztindung ist, die allein im Zusammenhang und als Folge yon einer inneren StSrung auftritt. Zwisehen diesen Ansiehten sind s~mtliche (~berg~nge vorhanden.DaB aueh nervSse Einfliisse eine grof]e Rolle bei den Ursachen des Ekzems spielen, ist wohl als sicher anzunehmen. Einer der Haupt-anh~nger dieser nervSsen Theorie ist Kreibich.Er definiert das Ekzem als eine vasomotorische Reflexneurose, ausgel6st durch Reize der verschiedensten Art, welche die Endignngen der sensib!en Epidermisuerven treffen und zu einer reflektorischen Entziindung in der Cutis fiihren. Kreibich kommt durch folgende ~berlegung zu dieser Ansieht: beim Ekzematiker trifft irgendein Reiz, sei es ein chemischer, thermisehe r, mech~niseher, parasitarer, toxiseher auI den sensiblen Epidermisnerven. Diese Reize zusammen mit dem entstehenden Jucken 15sen einen Reflex aus, der entweder iiber das Rfickenmark oder in dem naeh Art yon Langley angenommenen Axonreflexbogen verl~uft. Der Reflex kehrt entweder an die Stelle der peripheren Reizung zuriick oder tritt auch an einer anderen tt~utpartie auf und verr/it h/~ufig dureh seine Art (Symmetrie, Lok~lisation in einem met~meralen Feld oder Grenzlinie) seinen zentralen Charakter. Die MSglichkeit lokaler knrzer Reflexe (sogenannter JLangleyscher Axonreflexbogen) muB abet aueh zugegeben werden.Der Reflex antwortet mit allen Formen der vasomotorischen Erregung und mit allen Formen der Entziindung. Von der Labilit~t des Gef~Bsystems h/ingt es ab, ob es nur zu einer Hyper~mie, einer entziindliehen Exsudation oder schliefilieh zu einem Ekzem kommt. Dieser Vorgang wird uber nur bei disponierten Personen beobaehtet, sogenannten Ekzematikern. Worin diese Disposition zu suchen ist, ist noeh ganz ungekl~rt; m5glicherweise beruht sie, wenigstens zum Tell, anf einer abnorm leichten Ansprechbarkeit des vegetativen iXervensystems.

Zusammenfassung SummaryComparative studies on the quality of crude oils and protein isolates obtained by traditional and novel technologies. Part 3. Processpecific influences on chemical, physicochemical and functional properties of protein isolates from sunflower seeds The production of protein isolates from sunflower seeds based on traditional technologies of oil seed processing (pre-processing, extraction) and novel technologies of direct extraction and displacement extraction is described. The quality of the isolates is assessed on the basis of their composition and properties.Protein isolates from crushed extraction cake gained by the traditional process of pre-pressing and solvent extraction meet with regard to their composition and properties only partially the requirements of food industry. The same applies to isolates produced by the "refining variant" of the displacement extraction procedure. On the other hand the protein isolates produced by direct and displacement extraction procedures after hydrothermal pretreatment are high quality food additives. Einfuhrung und ZielstellungBei traditioneller Verarbeitung von Sonnenblumensamen anfallende proteinreiche PreDund Extraktionsriickstande sind u. a. infolge einer hohen thermischen Belastung in ihrem Gebrauchswert stark eingeschrankt, sie werden daher nahezu ausschlieDlich als Futtermittel verwendet. Es besteht jedoch ein volkswirtschaftliches Interesse an der Nutzbarmachung '.