Effect of ascorbic acid on the foaming and gelling of globular proteins

Foam expansion and foam stability of plasma and egg albumen proteins were enhanced in the presence of increasing concentrations of ascorbic acid (0.1–1.0%). BSA showed the greatest improvement in foaming properties following treatment with ascorbic acid, whilst foaming properties of egg albumen were improved to a limited extent. A combination of partial acid hydrolysis and treatment with 1% ascorbic acid was required to dramatically improve the foaming properties of bovine blood plasma. In the presence of sucrose, foam expansion of both native and ascorbic acid-treated blood plasma was decreased. In contrast the foam expansion of ascorbic acid-treated egg albumen was greater although this effect decreased slightly on incubation. the gelation of ascorbic acid treated proteins increased with increasing temperatures over 80–90°C, particularly for BSA and blood plasma, and with increasing concentrations of ascorbic acid. Ascorbic acid-treated proteins exhibited enhanced surface and exposed hydrophobicity and reduced numbers of sulphydryl groups indicating the involvement of these factors in foam and gel formation.     

THE DEVELOPMENT OF TAINTS IN PASTEURIZED CREAM

A survey of 231 samples from 11 brands of cream showed that the keeping quality of pasteurized cream depends on the development of both bacteriological and non-bacteriological taints. The water agar test is suggested as a simple test that is able to predict bacterial spoilage and to identify correctly 95 per cent of those creams with a keeping quality at 5^oC of not less than 14 days. Spoilage that developed within three days was due to bacterial action in only 57 per cent of the samples.     

Allergenic Reactivity of Various Soybean Products as Determined by RAST Inhibition

Allergenic reactivity of soybean products (sprouts-Sp, tempeh-T, tofu-To, miso-M, mold hydrolyzed soy sauce-MHS, acid-hydrolyzed soy sauce-AHS and hydrolyzed vegetable protein-HVP) was determined using RAST inhibition. All products inhibited binding of serum IgE from a pool of soy-allergic adults to raw soybean extract bound to microcrystalline cellulose, showing competitive inhibition with increasing protein. M.T. To and MHS showed competitive inhibition only at much higher protein concentrations, suggesting fermentation may alter or desyroy allergenic epitopes. Selectle destruction of ep-itopes was seen for MHS. To. and nossiblv M and T where inhibition curve slopes were not identical to intact material. Probably protein(s) with antigens common to raw soybean survived during processing of HVP and germination of sprouts. Based on RAST inhibition, these products are potentially hazardous to soybean-allergic individuals.     

Sulfite Residues in Maraschino Cherries

A survey of 53 samples of maraschino cherries from 14 different processors revealed that total sulfite residues averaged 52.3 ± 44.7 ppm. However, 58.5% of the samples had less than 40 ppm total SO₂, while only 7.6% had greater than 120 ppm total SO₂ indicating that the distribution was skewed in the direction of lower residue levels. Free sulfite residues in the 53 samples were considerably lower averaging 14.2 ± 7.1 ppm. With free SO₂ levels, 35.8% of the samples had less than 10 ppm free SO₂, while only 5.7% had greater than 30 ppm free SO₂. With an average serving size of one cherry (3 - 7g), maraschino cherries would contribute only 0.16 – 0.37 mg per serving of total sulfites as SO₂.     

Effect of Nisin on the Outgrowth of Clostridium botulinum Spores

Nisin, an antibiotic produced by certain strains of Streptococcus lactis, is effective in preventing the outgrowth of Clostridium botulinum spores. Type A C. botulinum spores were the most resistant to the inhibitory action of nisin requiring 1000-2000 I.U. of nisin/ml for a 50% inhibition of outgrowth on TPYG agar plates. Type E spores were more sensitive requiring only 50-100 I.U./ml for 50% inhibition of outgrowth on TPYG agar plates. Type B spores displayed an intermediate level of sensitivity requiring 500-1000 I.U. of nisin/ml for 50% inhibition of outgrowth on TPYG agar plates. Similar levels of nisin were necessary to prevent spore outgrowth in TPYG broth and BHI broth over a 7-day incubation period. With prolonged incubation periods of up to 65 days in TPYG broth, spore outgrowth was observed sporadically at higher nisin levels with the type A and B spores which may indicate some decomposition of nisin with storage. Nisin levels of 5000 I.U./ml for the type A spores and 2000 I.U./ml for the type B spores and the Minnesota E spores were insufficient to prevent spore outgrowth by C. botulinurn in cooked meat medium. For the Beluga E spores, a nisin level of 2000 I.U./ml was necessary to prevent spore outgrowth in cooked meat medium. The need for higher levels of nisin in cooked medium to prevent spore outgrowth may be due to the binding of the nisin by meat particles.     

Environmental Auditing in the Public Sector: The Lancashire Experience

Lancashire County Council was one of the first local authorities in the UK to audit the environment of its locality and to review the environmental impact of its operations. The paper outlines the reasons for this and how it has been put into effect. The management structure devised to carry forward and coordinate the initiative is outlined first, encompassing elements internal to the County Council and the establishment of a Lancashire Environment Forum. Secondly, the preparation of a county-wide state-of-the-environment audit is described, together with the implementation stages which have ensued. The paper is completed by an account of the County Council's internal review of the impact of its own activities.     

Two methods for predicting the multiaxial fatigue limits of sharp notches

In this paper the problem of the multiaxial fatigue limit estimation of sharply notched components has been addressed using two different methods: a critical distance method and a method involving modified Wöhler curves. These two methods had been previously developed by the authors, but required modification for use in conjunction with finite element stress analysis of sharply notched specimens subjected to multiaxial loadings. Initially, it was demonstrated mathematically that these methods are equivalent in terms of multiaxial stresses near the notch tip. Subsequently, by employing some well‐known uniaxial notch fatigue concepts, some assumptions have been made in order to extend the use of these methods to in‐phase multiaxial notch fatigue situations. Experimental data were obtained from tests conducted on V‐notched specimens subjected to in‐phase mixed Mode I and Mode II loadings. Both methods were successful in giving fatigue limit predictions with an error usually less than 15%. This is interesting because the two methods make quite different assumptions about the nature of fatigue crack growth in the vicinity of the notch.     

Magnetic Co2Y ferrite, Ba2Co2Fe12O22 fibres produced by a blow spun process

Gel fibres of Co2Y,Ba2Co2Fe12O22, were blow spun from an aqueous inorganic sol and calcined at temperatures of up to 1200°C. The ceramic fibres were shown by X-ray diffraction to form crystalline Co2Y at 1000°C, and surface area and porosity measurements indicated an unusually high degree of sintering at this temperature. The fibres also demonstrated a small grain size of 1–3 m across the hexagonal plane and 0.1–0.3 m thickness at 1000°C. This only increased to 3 m in diameter and 1 m thickness even at temperature up to 1200°C. The fibrous nature combined with the improved microstructures could be an important factor in improving the magnetic properties of this material.     

寿命与成形性能的完美结合——PrintForm HR成形陬

介绍了福伊特造纸织物最新开发的新产品——PrintForm HR,成形网，重点论述了这一产品的经线／纬线组合、纬线结构，以及使用效果。这种成形网采用SSB技术和8梭口反面结构，与常规结构相比，可以延长成形网的使用寿命、提高脱水能力井增强横向挺度。对于采用高填料含量且纸页质量和留着率要求较高的纸机，这种耐用的成形网效果明显。