A method is described for determining H 2 S, methanethiol and dimethyl sulphide in Cheddar-cheese headspace. Cheeses ranging in age from 2 to 12 months were analysed using a gas chromatograph equipped with a photometric detector. These cheeses were presented to a trained flavour panel for the assessment of quality and intensity of Cheddar cheese flavour.An attempt is made to correlate the concentration of sulphur compounds in the headspace with the average flavour scores. The results suggest that the flavour intensity of the cheese is related to the concentration of methanethiol in the headspace.A comparison of the sulphur compounds found in Cheddar cheese with and without characteristic flavour has indicated that methanethiol may be an essential component of Cheddar flavour (Manning, 1974). The role of H 2 S in Cheddar flavour remains uncertain. Lawrence (1963) found that although the concentration of H 2 S in cheese increased during the first 4 months of ripening and then remained at about the same level the flavour intensity of the cheese continued to increase throughout the 40 weeks ripening period. On the other hand, Kristoffersen & Gould (1960) found no consistent change in H 2 S concentration with ripening time, but observed positive correlations, highly significant for older cheese, between H 2 S concentration and flavour scores for cheese of the same age. Dimethyl sulphide has been found in cheeses made with and without starter organisms (McGugan et al. 1968; Manning, 1974).The purpose of this investigation was to examine cheese at various stages of ripening to determine whether the formation of volatile sulphur compounds methanethiol, H 2 S and dimethyl sulphide could be correlated with flavour. The flavour of the cheese was assessed by a trained panel, whose members were required to evaluate the quality and intensity of Cheddar flavour and the nature and degree of off-flavours.The headspace over the cheese was analysed; by headspace is meant the vapour mixture emanating from the surface of bore holes in the cheese. Sulphur-containing compounds in the headspace were analysed by means of a gas chromatograph equipped with a sulphur-specific photometric detector.

Organoleptic assessments by the NIRD panel of Cheddar cheeses made with Streptococcus cremoris NCDO 924 or 1986, either in enclosed vats excluding nonstarter flora or in open vats, showed that high viable starter populations in curd did not give stronger‐flavoured cheese, but led to the development of bitterness. Cheeses made in open vats developed typical flavour more rapidly than those made in enclosed vats. Maturation temperature was the most important factor in determining the flavour intensity; cheese ripened at 13d̀C for six months had stronger flavour than corresponding ones ripened at 6d̀C for nine months, irrespective of the starter or vat used.

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The mammogenic potency of miroestrol, an oestrogenic substance isolated from the tuberous roots of the leguminous plant Pueraria mirifica, was estimated as 0\m=.\70 (with 5% fiducial limits of 0\m=.\40and 1\m=.\18) relative to oestradiol in the ovariectomized rat, and as 2\m=.\2 (with 5% fiducial limits of 1\m=.\2and 4\m=.\9 relative to oestrone in the mouse. The effects of miroestrol on the body weight and weights of the endocrine glands, with the exception of the thyroid in the rat, were qualitatively similar to those of oestradiol and oestrone. In the rat oestradiol (0\m=.\1\g=m\g/day) inhibited the increase both in body weight and thyroid weight that occurred after ovariectomy, whereas miroestrol (0\m=.\1\g=m\g/day) inhibited only the increase in body weight.

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