摘要:

The grease resistance of a wide variety of packaging materials was tested before and after creasing and ageing, using a modification of TAPPI method T454m-44. Kraft and sulphite were of little or no value as grease barriers even after paraffin wax coating or impregnating. Vegetable parchment and 'greaseproof' paper were superior to kraft. The grease resistance of glassine was 5 to 10 times greater than that of either greaseproof paper or vegetable parchment. Polyethylene, in turn, was considerably more resistant than glassine, and just slightly less resistant than all grades of "Cellophane", and cellulose acetate, cellulose nitrate, ethyl cellulose, Pliofilm, vinylite, and Saran.Creasing glassine caused large reductions in its grease resistance, especially when heavy basis weights were tested. Paraffin wax coatings seemed to be more effective in improving grease resistance when dense base stocks were used. On kraft, a heavy wax coating was necessary to produce a small improvement, while on glassine only a very light coating was required, to bring about considerable improvement in grease resistance. Ageing many materials at 140° F. markedly reduced their grease resistance. An exception to this was glassine, most samples of which had greater resistance to grease penetration after ageing. Neither ageing nor creasing appreciably affected the grease resistance of Cellophane, or the thermoplastic films tested.

ISSN:1923-4287    

DOI:10.1139/cjr47f-001

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Water-vapour penetration was measured on pouch, flat, wedge, and square liner bags fabricated from Reynold's Metal A-51, 300 M.S.A.T. "Cellophane" coated 40 lb. per ream with a flexible wax composition, 55 lb. laminated bleached glassine, and 300 M.S.A.T. Cellophane. The bags were closed, where the material permitted, by heat-, glue-, and pressure-sealing, and by folding with or without tin-tie closures.When Reynold's Metal A-51 or waxed Cellophane was used, excellent water-vapour resistance could be achieved with any of the bag types investigated, and a folded closure was as efficient as a heat-seal. With all materials except 300 M.S.A.T. Cellophane, bags made with glue were almost as good as those with heat-sealed construction. Unwaxed Cellophane or glassine provided more protection when the simpler forms of bags (pouch) were used. With unwaxed Cellophane, heat-sealing appeared to make a better liner than the use of glue, and a heat- or glue-sealed closure was superior to a double fold.

ISSN:1923-4287    

DOI:10.1139/cjr47f-002

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Milk powders of 1% butterfat content, produced in the fall of the year, had higher initial palatability scores than similar powders prepared in the spring.. The skim milk powders from fall milk decreased in quality throughout a storage period of 16 wk. at temperatures of 80°, 100°, or 120° F. Similar powders from spring milk stored at 80° F. increased in quality throughout the storage period while those stored at 100° and 120° F. first increased and then decreased in quality. Powders of 26 or 28% butterfat, produced in the spring or in the fall, had equal initial palatability scores and when stored deteriorated equally. Fail milk powder containing 30% butterfat was better initially than the comparable spring sample, but, when stored, quality changes in both types were about equal. At each storage temperature all whole milk powders deteriorated at about the same rate.

ISSN:1923-4287    

DOI:10.1139/cjr47f-003

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Breaking out the egg on a glass plate and measuring the height and width of the yolk in position in the white is a rapid and easy method of determining yolk index. The correlation coefficient between this method and one of the more laborious methods, in which the white is removed, is.97. The prediction equation isy = −0.001 + 0.9172x.

ISSN:1923-4287    

DOI:10.1139/cjr47f-004

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Moisture content of the meat and solid content of the broth from open- and pressure-cooked chicken and fowl were investigated during cooking and subsequent processing. During cooking, pressure-cooked meat lost more moisture than open-cooked meat, but during canning and separating the reverse was true. For these reasons, approximately 4 oz. of open-cooked meat, as compared with 3.6 oz. of pressure-cooked meat, must be canned to obtain 3.5 oz. of meat in the finished product. During cooking there was a greater loss of moisture from dark than from light meat. Under all the cooking conditions used the loss of weight from fowl during processing and separation was greater than that from chicken meat. The loss in weight of meat during canning and processing is mainly due to moisture changes rather than the loss of solids.

ISSN:1923-4287    

DOI:10.1139/cjr47f-005

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Numerical ratings of the salty taste of freshly cooked portions of 80 pieces of Wiltshire-cured Canadian bacon by each member of a panel of 23 judges are analysed statistically, with results in general qualitative agreement with those previously reported for other palatability tests made in the same laboratory. Single assessments were subject to considerable random variation superimposed upon wide differences between individuals in respect of both tolerance and sensitivity. Nevertheless, a significant element of correlation made possible reproducible results, although it is calculated that to discriminate differences of the order of 5% on the organoleptic scale would have required 35 and 62 judges for intra- and inter-panel comparisons, respectively. The preferred degree of saltiness corresponded to a sodium chloride content of the cooked bacon of aboutin the absence, and of roughly 4% in the presence ofparts per thousand of sodium nitrate.

ISSN:1923-4287    

DOI:10.1139/cjr47f-006

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Further evidence that iso-linoleic acid is related to the unpleasant odour development when partially hydrogenated linseed oil is heated is as follows:(a) Partially hydrogenated perilla oil, containing considerable iso-linoleic acid, developed the same odour when heated, as did partially hydrogenated linseed oil.(b) A concentrate of iso-linoleic acid developed a similar odour when it was heated. Distillation of the acid, or removal of unsaponifiable substances, had no effect on the odour development.(c) When fatty acid fractions obtained by crystallization of the acids from hydrogenated linseed oil were re-esterified with glycerol, and subjected to the heat test, most odour development occurred in the fraction containing most iso-linoleic acid.Increasing the selectivity of hydrogenation did not greatly affect the formation or hydrogenation of iso-linoleic acid. However, products of high temperature (200° to 250 °C.) hydrogenations were softer for equivalent iodine numbers, and had lower melting points than those from low temperature hydrogenations.Hydrogenation of partly polymerized linseed oil yielded a product that when heated did not develop the characteristic odour of hydrogenated linseed oil.

ISSN:1923-4287    

DOI:10.1139/cjr47f-007

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Flavour reversion could not be detected in samples of hydrogenated linseed oil stored under vacuum in the dark. In samples exposed to the air, reversion occurred without appreciable increase in peroxide oxygen or Kreis values, particularly in products of low iodine number, while accompanying changes in fluorescence were slight and erratic. An observed 'bad area' for susceptibility in the lower iodine number range suggests that iso-linoleic acid (4) is not the only cause of reversion. No improvement in flavour stability was obtained by: low to high temperature hydrogenation (110° to 240 °C. (230° to 464° F.)), removal of impurities from the oil, or the use of a linseed oil fraction from a commercial polymerization process.

ISSN:1923-4287    

DOI:10.1139/cjr47f-008

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Biscuits commercially prepared with shortenings of four types (compound animal–vegetable, blended vegetable, hydrogenated vegetable, and stabilized, hydrogenated vegetable) were coarsely ground and stored in sealed cans at 26.7°, 43.3°, and 60 °C. (80°, 110°, and 140 °F.). Deterioration was assessed by peroxide oxygen and pH determinations, and by flavour scores. The results obtained for biscuits stored at 60 °C. were not indicative of behaviour at the lower temperatures. Flavour score was the most useful estimate of biscuit keeping quality, especially at 26.7° and 43.3 °C. Peroxide development was appreciable only in biscuit material stored at 26.7 °C.Biscuits prepared with hydrogenated vegetable shortenings were generally more stable (average storage life: 84, 22, and 13 weeks at 26.7°, 43.3°, and 60 °C., respectively) than those prepared with animal–vegetable or blended vegetable shortenings. However, shortenings with Swift stabilities (110 °C.) greater than 40 hr. did not yield products of increased keeping quality.

ISSN:1923-4287    

DOI:10.1139/cjr47f-009

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Mean values for measured properties of 33 samples of lard obtained from 26 packing plants across Canada were: iodine number, 58.7; saponification number, 193.9; melting point, 43.5 °C.; smoke point, 382° F.; colour, 8.8Y, 1.6R; unsaponifiable matter, 0.43%; fatty acid composition: saturated, 45.6%, oleic, 44.7%, linoleic, 8.7%, linolenic, 0.6%, arachidonic, 0.4%; storage life at 26.7 °C., 9.2 weeks; Swift stability, 3.5 hr.; iodimetric peroxide, 1.6 ml. of 0.002 Nthiosulphate per gm.; ferrometric peroxide, 9.7 m.e. per kgm.; Kreis test, 9.9; Stamm test, 2.3; alpha-dicarbonyl test, 3.4; free fatty acid, 0.4%; fluorescence, 79.2. The distribution of values is shown by histograms.Simple correlation coefficients computed between measured properties showed the following to be associated: melting point with iodine number; free fatty acid content with melting point, smoke point, and red colour; storage life at 26.7 °C. with log of Swift stability and initial ferrometric peroxide, Kreis, and alpha-dicarbonyl values.

ISSN:1923-4287    

DOI:10.1139/cjr47f-010

出版商:NRC Research Press    

年代:1947

数据来源: NRC