The effect of germination conditions on sorghum malt quality and malting loss was studied by germinat ing sorghum for different periods of time up to 6 days over a range of temperatures (24 to approximately 36°C) and moisture conditions. The moistureconditions varied fromthatsufficientto maintain green malt weight to that where surface moisture remained on the malt throughout germination. Germination time, temperature, moisture and the three possible pairwise interactions all had a highly significant effect on malt diastatic power, free a-amino nitrogen and extract. Malting loss was highly significantly affected by germination time and moisture and their pair-wise interaction. However, over the range examined, germination temperature had no significant effect on malting loss. In general diastatic power, free a-amino nitrogen, extract, and malting loss all increased with germination time. Germination tempera tures of 24°and 28°C were both equally good for the development of diastatic power, free a-amino nitrogen and extract but higher temperatures were progressively worse. Distatic power, free a-amino nitrogen, extract and malting loss were, in general, all increased by high moisture during germination.However, high moisture and a negative effect on diastatic power towards the end of the germination period.Key words: Sorghum, malting, diastatic power, free amino nitrogen, extract, malting loss. IntroductionMalted sorghum {Sorghum bicolor (L.) Moench) is used in the brewing of the traditional alcoholic beverage of Southern Africa, known as sorghum beer.13'14 In sorghum beer brewing, unlike lager brewing, diastatic power is a much more important criterion of malt quality than extract.10 This is because the diastatic power of sorghum malt is intrinsically rather low14 and because the malt has to act on twice its own weight of starchy adjunct during mash ing.12'14 Another important parameter of malt quality in sorghum beer brewing is free a-amino nitrogen content. This is again due to the fact that the relative percentage of malt in the mash is low. Furthermore-, sorghum malt pro duces only a small additional amount of free a-amino nitro gen during mashing19 and the starchy adjunct (maize grits or sorghum grain1 ) contributes very little to the final free a-amino nitrogen content of the wort.6Recently, there has been some interest in the feasibility of using malted sorghum for the brewing of lager becr.8>15i '7 This topic is of interest to brewers in countries where the climate is suitable for the cultivation of sorghum but not barley.l>Sl17 However, Nout and Davies8 considered that sorghum malt was not even adequate as an extender for barley malt, because of its low extract and poor filterability.Research into the effects of malting conditions on the quality of sorghum malt has been limited.7*10'1'116 Their effects on free a-amino nitrogen content having until now received no attention whatsoever. This paper describes an investigation into the effect of germination time, tempera ture and moisture on the developme...
Fatty acid esters, high in linoleic acid, were prepared and stored for long-term engine tests. Storage tests with these esters were undertaken to obtain more information on optimal storage requirements and general stabi1ity characteristics.Samples were kept at three temperature levels (20 C, 30 C and fluctuating around SO C) for a 90-day period and were removed at regular intervals for chemical and physical analysis. The influence of air, temperature, light, TBHQ and contact with mild steel was evaluated by comparing the free fatty acid, peroxide, anisidine, ultraviolet absorption, viscosity and induction periods. A statistical model was used to evaluate the data and to reduce the large number of data points to comparable curves.Storage of esters in contact with air, especially at a temperature above 30 C, resulted in significant increases in peroxide, ultraviolet absorption, free fatty acid, viscosity and anisidine values. Exclusion of air retarded oxidation at all temperature levels.A direct relationship between viscosity increases and oxidation parameters was evident. Exposure to light caused a small increase in the oxidation parameters of esters stored at the highest temperature level. Addition of TBHQ prevented oxidation of samples stored under moderate conditions. Under unfavorable storage conditions the anti-oxidant was no longer effective. Mild steel had very little effect on the oxidation parameters. Only the anisidine values of samples stored at the highest temperature level were slightly increased. Methyl esters performed slightly better than ethyl esters during the storage test.The following practical guidelines for storage of fatty acid ester fuels are: (i) airtight containers should be used; (ii) the storage temperature should be <30 C; (iii) mild steel (rust free) containers may be used, and (iv) TBHQ has a beneficial effect on oxidation stability.
Young baboons were fed semisynthetic, vitamin D-containing diets differing in calcium and/or phosphorus content over a 16 month study period. Diets low in calcium alone or low in both calcium and phosphorus led to the development of radiologic rickets and histologic features of osteomalacia at both 8 and 16 months. The diet which was low in calcium but which had a normal phosphorus content was associated with histologic features of hyperparathyroidism at 16 months; such features did not develop in animals fed the low calcium, low phosphorus diet. Biochemically the low calcium, normal phosphorus diet was associated with a transient fall in serum calcium around 8 months, and a more persistent elevation in serum phosphorus and alkaline phosphatase values during the latter half of the study. These biochemical changes were not seen in the baboons on the low calcium, low phosphorus diet. These results confirm that histological changes can occur as a result of dietary calcium deprivation in vitamin D-replete animals.
There is some indication in the literature that ascorbic acid (vitamin C) may reduce the physiological responses to heat stress. Consequently, the effect of ascorbic acid ingestion on heat-strain indicators has been studied on a group of 60 mining recruits undergoing climatic room acclimatization. Of the 60 men, 19 received a daily dose of 250 mg ascorbic acid; 21 a daily dose of 500 mg ascorbic acid; and 20 received a placebo daily. Measurements of rectal temperature, heart rate, and hourly sweat rate were made on all subjects during the 4 h of heat exposure per day for 10 days. The wet bulb temperature was 32.2 degrees C, the dry bulb 33.9 degrees C, the air movement 0.4 m/s, and the work rate 35 W. The results indicate that the rate and degree of acclimatization, as assessed by 4th-h rectal temperature, is enhanced by ascorbic acid supplementation and that no differences in response could be shown between daily dosages of 250 and 500 mg of vitamin C.
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