Journal of the Science of Food and Agriculture

doi: 10.1002/jsfa.2740260501pmid: N/A

Dal Peruffo, A. Belin; Pallavicini, C.

doi: 10.1002/jsfa.2740260502pmid: 1160355

The isoenzyme patterns of glutamate dehydrogenase, malate dehydrogenase, leucine aminopeptidase and acid phosphatase in grape berries at various stages of ripening were determined by gel isoelectric focusing. The ripening of the grape berries was characterised by the appearance of new isoenzyme bands for malate dehydrogenase, acid phosphatase and glutamate dehydrogenase. Evidence of increase in the total enzyme activities during the ripening was obtained. Only one form of leucine aminopeptidase was found, but this also increased in intensity as ripening progressed.

Williams, Anthony A.

doi: 10.1002/jsfa.2740260503pmid: N/A

Profile assessment of a cider or perry and correlation of the information with analytical data offer many advantages when evaluating the sensory significance of the large number of components detectable in such beverages by gas chromatography and other analytical techniques. The application of this method together with the general need to be able to record and communicate information on the flavour of beverages makes the development of a meaningful language essential. All terms used in such a language must be universally understandable and accurately definable, preferably in terms of readily available standards. The progress in the development of such a vocabulary for assessing the aroma of ciders and the incorporation of the results into a profile assessment sheet are reported.

Kolderup, Fredrik

doi: 10.1002/jsfa.2740260504pmid: 1160356

Five varieties of common spring wheat were cultivated under controlled conditions at five temperatures from 12 to 24 °C. From the time of heading three day‐length treatments were applied at each temperature: 10 h, 24 h, and natural day length. Nitrogen content in the grains increased by 46–124% with increasing temperature, and also increased significantly with extension of the photoperiod. Natural days, supplying more light energy, gave lower nitrogen contents than the other treatments. Protein yields per pot were more constant. The relative amounts of lysine, valine, and threonine decreased with increasing temperature and extension of the photoperiod, while glutamic acid, proline, and phenylalanine increased. However, at the highest temperatures this trend was hardly apparent. Protein fractionation showed that the decrease in lysine was correlated with an increase in the ratio of alkali‐soluble to salt‐soluble proteins.

Chaytor, John P.; Crathorne, Brian; Saxby, Michael J.

doi: 10.1002/jsfa.2740260505pmid: 1160357

Techniques are described for the extraction and analysis of amines from foods, employing gas chromatography and mass spectrometry. The presence of 2‐phenylethylamine is demonstrated in samples of chocolate, cheese and certain red wines. Subsequent clinical trials have shown that this amine precipitates migraine attack in dietary migraine sufferers.

Gorin, Natalio; Rudolphij, Jan W.; Heidema, Frouwke T.; Van Der Vuurst De Vries, Rid G.

doi: 10.1002/jsfa.2740260506pmid: N/A

The ripening process of “Golden Delicious” apples, harvest 1972, during storage at 4 °C under controlled atmosphere, was assessed sensorially with a palatability test based on the attributes flavour, sweetness or sourness, and texture. After 130 days of storage 50% of the apples had flavour pertaining to ripe (pleasant to eat) stage and 50% pertaining to overripe (unpleasant to eat). The same proportions for sweet‐sour relation (ripe and overripe) and texture (ripe and overripe) were reached after 180 days of storage, when fruits became clearly inedible. This showed that flavour was the first attribute to deteriorate and therefore it constituted the limiting factor of the internal quality of apples. Consequently the following criterion was adopted: the internal quality of a batch of apples remained satisfactory until the proportion of apples assessed as of ripe flavour (40–50 %) was similar to the proportion of apples with overripe flavour (40–50%). This moment coincided with the inflexion point in the graph of sucrose content per initial fresh weight of apples against time and with the fall of L‐malate below about 0.40%. The inflexion point of the graph for citrate was earlier than the inflexion for sucrose.

Vakis, Nikos; Marriott, John; Proctor, Felicity J.

doi: 10.1002/jsfa.2740260507pmid: N/A

The conditions of shipment were monitored during 1971 for a number of sea shipments of carrots exported from Cyprus. The carrots were packed in cotton nets with and without perforated polyethylene liners and cooled following stowage in in the hold. A temperature of 5 °C was achieved in the hold within 3–4 days following the commencement of cooling for both packing methods. During 1972 an assessment of outturn was made on a number of trial shipments during discharge in the United Kingdom and was combined with simulated “market life” holding trials for the two packing methods. Carrots packed in lined nets lost 2–4% less weight, were substantially fresher in appearance and contained no more infected roots than those in unlined nets during the “market life” holding trials.

Dellamonica, Edward S.; Huhtanen, Charles N.; Strolle, Eugene O.

doi: 10.1002/jsfa.2740260508pmid: N/A

The microbial activity and chemical composition of concentrates prepared from potato starch factory waste were studied. Concentrates stored at room temperature and 35 °C showed gas formation and caramelisation; this study showed that these were not caused by indigenous aerobic or anaerobic bacteria. Chemical composition data indicate that these visible signs of instability were due to non‐enzymatic browning. Results also reveal that enzymic proteolysis is occurring. Potential use of this product, e.g. as an animal feed, is very limited and will require a final drying.

Wessels, Jacobus P. H.; Moodie, Iain

doi: 10.1002/jsfa.2740260509pmid: 1160358

In three experiments fish meals of different origin and treatment were given to chickens in short‐term feeding trials after varying storage periods. Diets were supplemented with amino acids in these experiments, most of which were of factorial design, in such a way that the first limiting amino acids of the meals could be established. The body moisture content of three or four groups of chickens per treatment served as criterion of nitrogen (N) retention by the chickens. In the first experiment consisting of two trials, a pilchard meal stored for over 70 weeks and an anchovy meal stored for 74 weeks were both shown to have methionine as first limiting amino acid but only whenthe former was stabilised with ethoxyquin and the latter was not. Several of the trials in the second experiment involved fish meals stored under nitrogen. Such meals have not been used in similar experiments before. L‐lysine hydrochloride supplementation of diets which contained full (i.e. with solubles added) fish meals depressed N retention, as did L‐isoleucine when added at a high level (0.5%). This effect of lysine was also demonstrated when used in a diet which contained a commercial pilchard full meal which had been stored for about 6 months. On the other hand, lysine was shown to be the first limiting amino acid of a fish meal to which solubles had not been added. When the stabilised full meal used in Experiment II had been in storage for 108 weeks a positive reponse in chicken N retention to methionine supplementation of diets containing this meal occurred (Trial IId). In subsequent trials with these ageing stabilised meals cystine and/or methionine supplementation and later particularly supplementation with glycine led to better N retention by chickens. Unstabilised stored meals seem to have a sulphur‐containing amino acid as first limiting. In most instances where comparison was possible diets containing stabilised fish meals gave greater chicken body N retention than those containing similar unstabilised meal.

Lodhi, Gopi N.; Ichhponani, Jagmohan S.

doi: 10.1002/jsfa.2740260510pmid: 1160359

An experiment was conducted to compare the feeding value of deoiled rice polish (DRP) with rice polish (RP) for White Leghorn pullets during growth and egg production. DRP was added at 20 and 40% levels replacing RP without adjusting energy and nutrients in the rations. The 40% DRP ration was offered to the pullets either at 1 week or 18 weeks of life. Results showed that the nutritive value of DRP compared well with RP for growth and productive performance though at the cost of 9 to 11% increase in feed consumption but metabolisable energy (m.e.) conversions were comparable. Furthermore, the age at which DRP feeding was initiated, had no effect on egg production. The average egg production for a period of 162 days was 73.4, 73.9 and 72.5% respectively in groups receiving 0, 20, 40% DRP. The increasing level of DRP reduced the egg size slightly but significantly probably due to low content of linoleic acid in the ration.