Journal of the Science of Food and Agriculture

Knight, R. A.; Menlove, E. M.

doi: 10.1002/jsfa.2740121001pmid: N/A

Because of conflicting statements in the literature, experiments have been carried out in which spores of moulds commonly associated with mouldy bread have been incorporated in bread doughs before baking. It has been demonstrated that such moulds and the ascospores of Neurospora tetrasperma are killed well before the end of the baking period. This evidence supports the contention that in normal bakery practice moulds do not survive baking and that mould growth on bread is due to post‐baking contamination with mould spores.

Byers, M.; Jenkins, G.

doi: 10.1002/jsfa.2740121002pmid: N/A

In connexion with the production of leaf‐protein in quantity, the effect of gibberellic acid on the yield of dry matter and crude protein, and on the extractability of the protein, was studied with spring vetches (Vicia sativa L.). A single spraying with gibberellic acid did not significantly affect the dry matter or crude protein in the foliage at the first cut, nor did it affect the extraction. The yields of dry matter and crude protein at the second cut were significantly lowered when the crop had been sprayed before the first cut. Two additional sprayings of gibberellic acid after the first cut further decreased these yields at the second cut. in both these cases the yields of extracted protein at the second cut and the combined yields from the first and second cuts were significantly lower than the corresponding yields from the unsprayed plants. Spraying with gibberellic acid before the second cut only, did not affect the dry matter but lowered both the yields of crude and extracted protein, although the combined yields from the two cuts were not significantly lowered. Hence, gibberellic acid not only fails to increase the leaf‐protein extractable from spring vetches, but under certain conditions decreases it.

Tew, R. P.; Sillibourne, J. M.

doi: 10.1002/jsfa.2740121003pmid: N/A

Post‐blossom applications of endrin emulsion to fruiting blackcurrant bushes at rates equivalent to 0.0375 and 0.05% endrin left harvest residues, estimated by two chemical methods and by microbioassay, exceeding 1 p.p.m. Some evidence has been obtained that these residues do not pass into expressed juice.

Tew, R. P.; Sillibourne, J. M.; Silva‐Fernandes, A. M.

doi: 10.1002/jsfa.2740121004pmid: N/A

Persistence and harvest residue studies on apples have been undertaken using the codling moth insecticides lead arsenate, DDT, 1‐naphthyl N‐methylcarbamate (arylam; Sevin) and the OO‐dimethyl and the OO‐diethyl S‐(3,4‐dihydro‐4‐oxobenz‐1,2,3‐triazin‐3‐ylmethyl) phosphorothiolothionates (azinphos‐methyl and ‐ethyl (Gusathion and Gusathion A), respectively). After application of these insecticides at commercially used times and rates, harvest residues do not constitute a consumer hazard, except upon occasion with lead arsenate.

McFarlane, J. A.

doi: 10.1002/jsfa.2740121005pmid: N/A

Twenty‐seven 100‐lb. bags of rice bran were sprayed on their upper sides with approximately 160 mg. of malathion per sq. ft. as each layer of a 3 × 3 × 3 stack was completed. Finally the sides of the stack were similarly sprayed. Samples (1000 g.) were taken from single bags, or from grouped bags, 1 and 3 weeks after spraying in order to assess the degree of contamination of the bran. A single sample of the bran obtained by brushing out a number of the sampled bags was also taken on each occasion. Contamination (estimated by a standard analytical procedure) was not more than 0.5 p.p.m. in samples drawn after 1 week from the bulk of the contents of tested bags, and 1.6 p.p.m. in the residue (approximately 1000 g.) obtained by brushing out six bags. Overall contamination was estimated at not more than 0.51 p.p.m., allowing for contamination in both the main bulk and the residual bran. Contamination in samples taken 3 weeks after treatment was found to be nil in all of three samples taken from the mixed contents of nine bags. Contamination in the residual bran (approximately 1400 g.) obtained by brushing out the same nine bags was found to be 0.8 p.p.m. Maximum overall contamination at 3 weeks was estimated at not more than 0.11 p.p.m. In a subsequent test a single lightweight (16‐oz.) jute bag containing 100 lb. of bran was heavily oversprayed, set aside for 1 week, and the contents subsequently stored for 4 more weeks in a clean bag. Samples taken after 1,2 and 5 weeks showed only low levels of malathion contamination.

Bender, A. E.; Ballance, P. E.

doi: 10.1002/jsfa.2740121006pmid: N/A

A volatile fraction obtained from meat extract was examined by gas‐liquid chromatography. Twelve compounds were identified (methyl mercaptan, acetaldehyde, ethyl mercaptan, dimethyl sulphide, acetone, ethyl methyl ketone, methanol and ethanol—which have also been shown to be present in meat by other workers—together with hydrogen sulphide, propionaldehyde, isobutyraldehyde and isovaleraldehyde) but others may be present.

Chang, C. D.; Kononenko, O. K.; Herstein, K. M.

doi: 10.1002/jsfa.2740121007pmid: N/A

By a two‐step procedure consisting first of digestion with hot water and then ammoniation at elevated temperature it is possible to introduce nearly 4% of bound nitrogen into whole bagasse. the hemicellulose constituent of bagasse is labile to ammoniation while the α ‐cellulose and lignin are not attacked. the nitrogenous substances can be quantitatively extracted with water. They consist of 70–80% caustic‐stable nitrogen which is found, by paper chromatography, to include imidazoles.

Cornford, S. J.

doi: 10.1002/jsfa.2740121008pmid: N/A

An investigation into the factors affecting fruit holding in high‐ratio cake batters is described in relation to the results of baking tests and measurements of the rheological properties of the batters. the cake batters behaved as plastic materials having a small yield value and flow properties in which shear stress varied almost linearly with square root of rate of shear. Yield value and apparent viscosity showed minimum values in the temperature range 140–160°F. Chlorine treatment of the flour was a major factor affecting fruit holding and its mechanism was to permit greater swelling of the starch at low temperatures, below the normal swelling temperature, which increased the yield value of the batter. Reduced protein content and coarse particle size of the flour were detrimental to fruit holding. Other factors examined were different acid ingredients, salt, type of fruit and egg quality.

Chang, Annie Tom; Ross, Edward

doi: 10.1002/jsfa.2740121009pmid: N/A

Hydrogen peroxide‐induced oxidation of ascorbic acid was found to be catalysed by several fruit juices. Products exhibiting peroxidatic activity were passion fruit, orange and pineapple juices, papaya and guava purees, liquid coconut products, and bottled (pasteurised) apple juice. A mathematical relationship between logarithm of juice dilution to initial reaction rate was developed. Passion fruit juice exhibited the highest peroxidatic activity on the basis of calculated intercepts and slopes. Several other fresh juices exhibited peroxidatic activity. Although the fruit juices reduce the activity in Fenton's reaction with ascorbic acid as substrate, the oxidising activity of the juices may not be a Fenton reaction. Coconut skim milk showed the highest inhibitory effect and passion fruit juice was second highest. Mechanisms for the inhibitory effect are considered.

Simpson, Beulah

doi: 10.1002/jsfa.2740121010pmid: N/A

Experiments have been carried out to determine the effect of crushing, under laboratory conditions, on the respiratory changes in pasture plants during drying. Results are presented to show that crushing often causes some stimulation of respiration but that the increase is not proportional to the amount of injury produced. Crushing increases the rate of drying, so the respiration of crushed material ceases much sooner than that of uncrushed material.