Flour Pellets Research Articles

Development of a rainfall test rig as an aid in soil block weathering assessment

Continual changes in earth technology and the search for new trends in soil block weathering practices have resulted in the development of a rainfall test rig (RTR). By positioning the water-spraying nozzle at a fall-height of 2.0 m and water pressure of 0.5 kg/cm 2, the device generates a rainfall intensity of 150 mm/h. On application to the standard flour pellet, the RTR discharges spectra of rainfall in which the range of drop sizes, impact velocities and kinetic energy appropriate to natural rainfall conditions. This was applied to soil block samples arranged on a 0.9-m 2 adjustable soil block holder (platform). The results of testing two different soil block samples, stabilised with cement, lime and lime/gypsum at varying proportions and cured at both room temperature (RT) and elevated temperature (ET), under controlled and reproducible artificial rainfall conditions, are briefly discussed.

Biological activity of sorghum tannin extracts on the stored grain pests Sitophilus oryzae (L.), Sitotroga cerealella (Olivier) and Tribolium castaneum (Herbst)

Tannin extracts of two sorghum, Sorghum bicolor (L.) Moench. cultivars, BKS 5 and BTX 623 were assessed for their bioactivity against the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and the angoumois grain moth, Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae), in whole wheat flour pellets, and against the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) in whole wheat flour at three treatment levels. The number of adult progeny was reduced and number of days to emergence increased by tannins extracted from both sorghum cultivars at all treatment levels. However, the effects were not significant in all cases. In a short-term (25 days) feeding test using S.oryzae adults, the presence of sorghum tannins from cv. BKS 5 in the pellets significantly reduced feeding by the insects.

An inexpensive, portable rain simulator: construction and test data

Construction details of an inexpensive, portable rain simulator are given. The dismountable components are easily transported on a light truck. The flat spray nozzles used produced rain with a >90% coefficient of uniformity over a 1-m2 test plot. Drop sizes and drop size distributions were determined using a flour pellet method. The appropriate equation of motion for accelerating drops and drag coefficients were used to calculate the impact velocity of individual drops and the kinetic energy of rain produced by various nozzles. Rainfall intensity can easily be varied in the range 10–150 mm h−1 and water consumption is low.

Accumulation and excretion of aluminium and iron by the terrestrial snail Helix aspersa

1. The snail Helix aspersa was fed one 24 hr meal containing Al, Fe or both together in barley flour pellets. Accumulation and distribution within the digestive gland, kidney, crop and remaining soft tissues were examined over the subsequent 30 days using atomic absorption spectroscopy (A.A.S.). 2. The digestive gland contained significantly ( P < 0.05) elevated levels of Al and Fe for 8 and 12 days. The digestive gland is the major sink for both Al and Fe in Helix. 3. The kidney rapidly accumulated Al and Fe but the increase was short-lived. The kidney may therefore be involved in the elimination of metal not incorporated into the digestive gland. 4. Iron was absorbed by the crop but Al was not. This may indicate a route of uptake of Fe into the digestive gland not shared with Al. 5. No obvious pattern of accumulation of Al and Fe were seen in the remaining soft tissues or the blood of Helix. 6. Aluminium is present in the faeces for 12 days suggesting that Al is released relatively slowly. 7. Presence of both Al and Fe in the feed induced a change in the pattern of accumulation in the digestive gland but not in the kidney, crop and remaining soft tissues. 8. The distribution of Al is discussed in relation to the suggestion that Al follows the ferretin pathway during accumulation.

The inhibitory effects of the molluscicide metaldehyde on feeding, locomotion and faecal elimination of three pest species of terrestrial slug

SUMMARYSingle meals on maize flour pellets containing 0, 0·5, 1, 2, 4, 6, and 8% metaldehyde were analysed in Arion hortensis (agg), Deroceras reticulatum and Deroceras caruanae, by attaching the pellets to a mechanical transducer from which signals were ultimately fed into a BBC microcomputer for on‐line analysis. Post‐feeding tests were used to investigate toxic effects of metaldehyde and the recovery of slugs was examined daily for 7 days. Bite rates were slightly lower and more irregular on metaldehyde meals especially in A. hortensis. The meal length and number of bites per meal were markedly inhibited by metaldehyde and inversely proportional to the concentration. The size of the bites was also reduced, by about 30%, in meals on 6% pellets compared with 0%. Clear symptoms of poisoning became evident during the meal or normally in the 16‐min test period immediately afterwards. In these tests slugs which fed on metaldehyde pellets showed a disruption of their ability to right themselves (after being placed on their side), less activity and a reduced probability of accepting a ‘dummy’ pellet containing no metaldehyde. It is hypothesised that feeding is prematurely terminated primarily because of the toxic effects of the metaldehyde and that aversion also acts to terminate the meal early, by decreasing the probability of continuing to feed as the meal proceeds. At higher concentrations of metaldehyde aversion may be more important than the toxic effects in ending the meal. Faecal elimination is delayed after metaldehyde meals and this contributes to mortality. The estimated lethal doses were about 0·2 mg/g body weight of slug in Deroceras spp. A. hortensis was less susceptible. To increase the likelihood of a lethal dose being ingested the inhibition of feeding needs to be overcome, at least partly, and the results presented indicate the need for a bait formulation which reduces the rate of absorption of the molluscicide from the gut.

THE USE OF EXTRUDED BARLEY, WHEAT AND MAIZE AS ADJUNCTS IN MASHING

The principles of extrusion cooking are summarised. In small scale trials good extracts were obtained from extruded barley when it was mashed with industrial enzymes, using a programmed temperature cycle. Extruded barley, wheat and maize and wheat flour yielded acceptable levels of extract when mashed with lager malt (70%) using a programme with 1 hour rests at 50°C and 65°C. The extracts obtained from these grists were increased above those obtained from grists of lager malt alone and the viscosities of the worts were reduced when the mashes were supplemented by preparations of bacterial enzymes. Enzyme additions also improved extract recoveries from all-malt mashes and reduced the viscosities of the derived worts. Using a temperature programmed mashing cycle and supplementary enzymes beers were prepared from a lager malt grist and grists in which the lager malt was partly replaced, by 30%, with extruded barley or extruded wheat, or extruded maize or wheat flour pellets. In every case wort was recovered relatively easily, the worts fermented normally and the beers were all fully acceptable, although their flavours did differ. However, in contrast to results of preliminary brewing trials, the head retentions of the beers made with adjuncts were unusually low, possibly because of particular enzyme additions.

Suppression of cell-mediated immunity following oral feeding of mice with palmyrah (Borassus flabellifer L) flour.

Inbred mice fed with a 40% mixture of palmyrah flour pellets showed a significantly reduced capacity to mount a delayed-type hypersensitivity (DTH) response to sheep red blood cells (SRBC). Maximal suppression of DTH was noted after 6 days of feeding but was detectable even after 2 days. Maximal suppression occurred when flour feed was maintained into the sensitization period (with SRBC). The suppressive effect was transferable to normal mice fed with pellets ad libitum by viable spleen cells from mice fed with the 40% flour pellet mixture for a period of 2 days. Further characterization of the cells which were able to transfer suppression showed them to be T cells, some of which possess the Ly-1 surface antigen. The cells appear to be negative for Ly-2 surface antigen. Histologically, no evidence of lesions was noted in the liver and other organs of recipient mice which received cells from flour-fed donors. We thus favour the interpretation that oral feeding of mice with palmyrah flour induced the generation of T suppressor cells which were able to suppress the DTH response to SRBC. The significance and implications of these findings are discussed.

Development responses of symbiotic and aposymbiotic weevils Sitophilus oryzae L. (Coleoptera, curculionidae) to a diet supplemented with aromatic amino acids

Developmental times of symbiotic and aposymbiotic strains of the rice weevil Sitophilus oryzae were compared, in response to changes in concentration of phenylalanine or tyrosine in whole wheat flour pellets. Aposymbiotic insects were shown to require more aromatic amino acids than symbiotic insects, since a very low supply (0.1%) resulted in faster growth (11%). Incorporation results of [ 3H]-tyrosine during the larval and pupal stages indicated that total tyrosine intake was lower in aposymbiotic insects, but the incorporation into the cuticle of both strains did not significantly differ. It is suggested that the slower growth rate of weevils without symbiotes is due, in part, to a less efficient utilization of exogenous tyrosine (in the food) and to a lack of endogenous tyrosine (supplied by the symbiotes).

The effect of processing treatments on the rumen microbial digestion in vitro of skimmilk powder protein

The microbial degradation of the protein of skimmilk powders manufactured and treated in different ways (high-, medium-, and low-heat spray, instant, roller, formaldehyde-treated spray) and milk powder products (skimmilk powder-wheat flour granules, skimmilk powder-barley flour pellets) was determined in anaerobic, rumen simulating conditions in vitro. The tests showed that milk protein was decomposed rapidly and extensively in rumen fluid buffer. The heat treatment had a slight N solubility-reducing effect. Formaldehyde treatment decreased the degradation of the protein at the beginning of the incubation, but this effect became smaller as incubation proceeded. After 48 h the N solubility of the treated skimmilk powder was about the same as that of untreated spray powder. The variation in the in vitro N solubility of formaldehyde-treated skimmilk powder was greater than with the other powders and products. The skimmilk powder-wheat flour granules were hard products which remained indigestible for several hours. At the end of the microbial digestion test the addition of skimmilk powder increased the N solubility of wheat flour protein. On the basis of the results obtained from the digestion test on a pelleted skimmilk powder-barley flour product it can be assumed also that the addition of skimmilk powder caused an increase in the N solubility of barley flour protein.

An Automatic Water Drop Collector for Field Use

A self-powered instrument for collecting rain drops is described. The rain drops are collected in flour filled trays and retained as flour pellets. The collector is triggered by the rain drops and its sampling rate varies with intensity of the rain. It operates remotely and once started samples automatically.