A simple and rapid method is described for extracting and measuring the nitric oxide-Selective extraction as a nitric oxide-haem-acetone complex is achieved by the use of Other meat pigments are not extracted under the conditions The acetone/water ratio is shown to be critical, maximum extraction being obtained AfterWith the inclusion of hydrochloric acid in the solvent, the method can be adapted to haem pigments present in cooked cured meat.an acetone/water solvent. used.with a ratio of 4 : I, due allowance being made for the moisture present in the meat. filtration, the optical density is measured spectrophotometrically. measure the total pigments present.

A method is presented for estimating the stability t o light of the colour of cooked hams, Some typical results obtained in presence and absence of air are considered. For the routine examination of samples, it is suggested that the stability may be conveniently expressed as the percentage of pigment remaining after one hour's exposure a t IOO foot-candles under stated conditions. enabling the complete fading curve to be obtained.

Variations in the pigment concentration of fresh pork, in different inuscles or in the same muscle, lead t o variations in the colour of the cooked cured pork. Two-fold variations were found for different muscles, these being due almost wholly t o myoglobin, and not to haemoglobin.The relationships between pH, cysteine, cystine, total pigments, nitroso pigments, and stability of colour have also been investigated, p€I appearing t o have opposite effects in the fresh pork and the cooked cured pork.

The changes taking place in this type of brine are shown to be: an increase of bacterial population (almost entirely a halophilic Gram‐negative rod of the Achromobacter species), with a consequential lowering of the oxidation/reduction potential, hence a reduction of nitrate to nitrite, and ultimately, when the potential is low enough, to gaseous nitrogen and free alkali, resulting in an increased pH. This reduction occurs at the expense of the lactic acid derived from the meat, which is oxidized to carbon dioxide. When the lactic acid has been used up, the large bacterial population, at the low potential and high pH then reached, produces ‘off’ odours by the decarboxylation of amino‐acids. No evidence of protein breakdown has been found.

Rapidly developing, short-life brines were discussed in Part I, but some brines have been found to develop into long-life brines of an acid reaction. I n these brines it is shown that the nitrite-producing, lactate-oxidizing organisms (Type A) are superseded by a slowgrowing micrococcus (Type B) which does not appear to have been described previously.The oxidation-reduction potential remains comparatively high, and lactic acid accumulates, making the brine acid. There appears to be no further metabolic activity, and the brines last indefinitely, but possess only poor curing qualities.