Previous investigations, iizcluding those of Kertesz and Sondheimer (8), Mackinney and Chichester (13), Meschter (14), and Nebesky et ccl.(15), have established that the red pigment of strawberry products is unstable in heating and storage, and that many factors can affect the rate at which this pigment degrades. I n a recent contribution from this laboratory ( 4 ) , the changes in color and pigment content of strawberry jellies were studied in relation to the amount of heat applied in processing and in storage.Much of the research carried out by the aforementioned investigators dealt with reactions of strawberry pigment in juice and/or partially purified pigment preparations. A notable exception was the investigation of Sondheimer and Kertesz (20 and 21) into the interrelationship of pigment., ascorbic acid, oxygen, and hydrogen peroxide.In the present research, the degradation of the anthocyanin primarily responsible €or the red color of strawberries was studied in pure pigment solutions. The effects of several factors (temperature, time, pH, oxygen, ascorbic acid, 5-hydroxymethyl-2-furaldehyde, and various potential stabilizers) on the rate of the degradation of this pigment were investigated quantitatively. An effort was also made to evaluate results obtained from the pure pigment study in terms of stabilization of the red color of strawberry juice. EXPERIMENTALPreparation of pure strawberry pigment. Chromatographic analysis reveals the presence of two red pigments in strawborry juice (14). One of them is present in much greater quantity than the other, and has been identified as pelargonidin 3-monoglucoside (19). In the early stage of the present investigation, the picration method (19) was used for the preparation of the major pigment. Later, it was found that paper chromatography results in a greater yield of major pigment and at the same time e e p arates the minor pigment, recently identified as eyanidin-3-glucoside by Lukton, Chi- Chester, and Mackinney (I,?), in recoverable quantities. The paper chromatographic technique used consisted of extracting strawberry juice with one-butanol, shaking the butanolic extract with 3 volumes of hexane, and streaking the red lower phase, which results from the prepious step, on Whatman No. 1 paper. Triangular strips of paper (8 in. base x 20 in. height) were used, with the mixture to be resolved applied as a narrow streak 1 inch from the base and parallel t o it. The solvent was a mixture of

This investigation was initiated with the purpose of studying the effect of acetic acid on certain microorganisms related to food spoilage with the hope of securing results of practical value. The main reasons for the use of acetic acid as a food preservative are its toxicity value, commercial availability, and low cost. The toxic effect on microorganisms of an increased hydrogenion concentration in the substrate is well established. Acetic acid and certain other organic acids appear to have a toxicity in excess of that which could possibly be due to the pH alone. The consensus of authorities seems to favor the theory that it is the undissociated molecule which is toxic. Kahlenberg and True (1896) found that the undissociated acetic acid molecule was toxic. Winslow and Lockridge (1906) found that acetic and benzoic acids were fatal to typhoid and colon bacilli at a strength at which these acids were but slightly dissociated. Wolf and Shunk (1921) concluded that the hydrogen-ions alone were not responsible for the toxicity of acetic acid. Bach (1932) states that at an interval where the pH has no importance, the undissociated part of the lactic acid is the active factor, although generally the hydrogen-ions control the antiseptic effect. In another paper (1932a) the same investigator suggested that the antiseptic action of formic, acetic, propionic, and butyric acids was connected with their influence on surface tension. Foster (1920) also contributed to the idea that the toxic effect was due to the 1 Contribution No. 352, Massachusetts Agricultural Experiment Station.

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Tenderness" is defined by Webster as "easily impressed, broken, cut, masticated . . . ." Easily impressed, broken, cut, masticated is the hope of all beef consumers. Market beef is classed by sex and age, graded for quality, fatness and conformation, and cut into retail portions, largely on the basis of its expected tenderness. Cook books describe dry heat, broiling, frying and roasting, as suitable for meat with natural tenderness. They give detailed directions for using moist heat to tenderize meat cuts that lack natural tenderness. Consumers, of course, also desire high food value, juiciness and good flavor in beef, but their first consideration is for beef that can be "easily impressed, broken, cut or masticated."Market and consumer experience, through the years, has discovered several factors that may influence the tenderness of beef. (a) Beef from freshly slaughtered carcasses (one to three days after slaughter) is less tender than beef from the same carcasses that have been aged or hung to "ripen" in a 0.7 to 1.7"C. (33 to 35°F.) chill room f o r 5 days or more. Normally beef aged for 10 days or longer is more tender than beef aged a shorter period. ( b ) Beef from young animals is more tender than beef from older ones. That means that beef from yearling and 2-year-old steers and heifers is usually more tender than that from older COWS o r bulls or even from 3-, 4-, and 5-year-old steers. (c) Beef from well-fed, well-fattened animals is usually more tender, and otherwise more desirable than thin beef from poorly fed animals. (d) Certain working muscles, such as those of the shank, neck, shoulder and round are less tender than the larger, Less worked muscles of the back and loin.Research has corroborated these opinions of the market and has determined many of the reasons for the differences noted. It is known that there are differences in the amount of connective tissue in animals of various ages and among the "working" and "less worked" muscles of the same carcass. It is recognized that muscle bundles swell or enlarge to some extent when animals fatten. Also aging, enzymes, acids and doubtless other agents change the character of muscle tissue. However, there is little information on the histology of muscle tissue as it relates to tenderness. * This paper is a portion of a

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