Henné. Absorption de la lawsone par le cheveu

Une étude préalable par chromatographie sur couche mince des extraits de cheveux traités à la lawsone (No. CAS 83.72.7) ou au henné (feuille de Lawsonia inermis ) confirme que la lawsone est bien le seul colorant du henné'.
Nous avons mis au point une méthode originale de 'gravimétric dynamique'qui nous a permis de déterminer l'absorption de la lawsone par le cheveu traité au henné.
Après un retard à l'origine, l'accroissement de masse est linéaire en fonction de la racine carrée du temps indiquant un processus de diffusion , la courbe s'incurve ensuite vers la saturation. Une étude en fonction de la température confirme le phénomène de diffusion.
La lawsone diffuse plus rapidement dans le cheveu traité au henné que traitéà la lawsone seule. De même l'extraction de la lawsone fixée dans le cheveu est plus rapide quand il a été traité par la lawsone au lieu du henné.
La lawsone diffuse plus vite et en plus grande quantité dans les cheveux châtain et décoloré que dans le cheveu noir.
Dans une compétition entre le henné et des tanins : à la surface du cheveu les tanins l'emportent, á l'intérieur la lawsone l'emporte.
La lawsone fixée aux kératines semble ètre un bon écran solaire.
Henna. Sorption of lawsone by hair     

Qualitätsveränderungen während der Lagerung von Speisezwiebeln (Allium cepa L.) 1. Mitt. Ernährungsphysiologische Qualitätsmerkmale

Quality changes of onions (Allium cepa L.) during storage. Part 1. Nutritional Quality Changes in the constituents of one-year old onion bulbs, occurring under outdoor-ventilated (NL) and machine-cooled (KL) conditions over 7 and 8 months of storage (x), have been described averaging 4 to 7 test series. Due to nutrient concentration by weight losses, the content of dry matter showed no changes. The amount of disaccharides including certain oligosaccharides decreased decisively, i.e. by 0.266 and 0.337 g/100 g fresh matter resp. per month of storage. In case of NL, however, the reduction became degressive by the end of storage according to the function y = α₀ ? β₁x + β₂x⁵. Monosaccharides increased significantly by 19 and 38% resp. till April or May with subsequent slight recession (function y = α₀ + β₁x ? β₂x⁵). Thus, total saccharides diminished moderately, i.e. linearly in case of NL and progressively growing with KL (y = α₀ ? β₁x²). The vitamin C total rose linearly and irrespectively of the storage temperature, by about 0.5 mg/100 g fresh matter per month of storage. Detailled consideration is given to physiological effects.     

Die Selbsthydrolyse der Kartoffelstärke. 2. Mitt. Selbsthydrolyse von Kartoffelstärkekörnern in wäßriger Suspension

Self Hydrolysis of Starch. Part 2. Self Hydrolysis of Potato Starch Granules in Aqueous Suspension. Tests with potato starch have shown that self hydrolysis at temperatures below the starting point of irreversible swelling leads to the formation of low molecular, soluble degradation products containing bound phosphoric acid. The rest of starch granules show increased reducing power as well as hydrothermically caused ageing. Approaching the end of self hydrolysis the substrate acts like thin boiling starch. During self hydrolysis phosphoric acid bound like ester is set free. Speed of self hydrolysis increases with increasing phosphorus content, whereas formation of free phosphate is independent of this factor.     

Qualitätsveränderungen während der langfristigen Lagerung von Knoblauch (Allium sativum L.) 1. Mitt. Äußere Qualitätsmerkmale

Quality changes of dry garlic (Allium sativum L.) during long term storage. Part I. External quality Two years of experiments with dry garlic (October planting) revealed comparatively high weight losses under outdoor-ventilating (+6.5 and 8.3 °C resp., φ = 69 to 71%) which varied between 0.76 and 0.81 weight-%/storage week. In the machine-cooled store (?1 to ?2 °C) they amounted to 0.50 w.-%/storage week. The losses were caused by a considerable respiration intensity and tendency to transpire (4 … 10 times resp. 4.6 times higher than with dry onions). Sprouting set in at the end of October in the outdoor-ventilated store only (1.7 to 3.0 w.-%/storage week). Rot losses (mainly caused by Penicillium and Botrytis spp.) rose under outdoor-ventilating over 24 storage weeks by 0.38 resp. 0.81 w.-% storage week, in the cold store they were by one third lower. In the outdoor-ventilated store market quality deteriorated by 3.8 to 4.5%; with machine-cooling only 0.8 to 1.1 w.-% were recorded per storage week. The physiological and parasitic characteristics of garlic demand machine-cooling at ?1.0 to ?2.0 °C from mid-September.