Xanthophyll and carotene storage stability in commercially dehydrated and freeze-dried alfalfa

Abstract

Alfalfa commercially dehydrated to yield meals with different moisture contents and freeze-dried alfalfa were subjected to accelerated storage conditions and analyzed for xanthophylls and carotene at periods extending to 12 weeks. Individual xanthophylls were determined by thin-layer chromatog-raphy. Meals which had undergone the lowest losses during dehydration suffered the highest losses during storage. Freeze-dried samples were the most stable. Ethoxyquin treatment reduced oxidative losses but isomerization losses of neoxanthin and violaxanthin continued.Research on stability of alfalfa carotenoids during storage has been largely concerned with carotene stability (Griffith and Thompson, 1949;Silker et al., 1944; Taylor and Russell, 1938; Van Der Veen and Olcott, 1967). The importance of xanthophyll content has grown, however, as alfalfa is increasingly used in poultry rations to provide desired egg and skin pigmentation. Thompson and Maclay (1952) studied xanthophyll retention in commercially dehydrated alfalfa stored at ambient temperature and concluded that xantho-

Oxycarotenoids in Poultry Feeds

“…Additional data are shown in Tables 18 and 19 and Fig. Knowles et al (458) found that alfalfa meals that showed the lowest losses during dehydration suffered the highest losses during storage. Even when stabilized with ethoxyquin, losses for xanthophylls of 20 and 40% are obatined after 4 and 12 weeks of storage at 100°F, respectively.…”

“…Inert gas storage has aided the retention of carotenes (407), as have treatment with an antioxidant, (83,270,340,458,511,579,600,802,890), and addition of animal fats (82,580). Inert gas storage has aided the retention of carotenes (407), as have treatment with an antioxidant, (83,270,340,458,511,579,600,802,890), and addition of animal fats (82,580).…”

“…Without EMQ, the losses for both were about equivalent (24 and 26%).Thompson and Maclay (807) reported on the results from nine samples of dehydrated alfalfa obtained from several different dehydrators. [From Knowles et al(458). Losses of 42 and 76% were observed for the carotenes and losses of 25-54% for the xanthophylls.…”

STABILITY OF CAROTENOIDS IN MODEL AQUEOUS SYSTEMS1

“…In the literature, there is some indication that an increase in the moisture content of the system accelerates the oxidation of carotenoids particularly in dried alfalfa leaves (Gogek 1968;Knowles et al 1968). …”

Carotenoid storage stability in drum dried PRO-XAN

“…Freezedried samples, therefore, provide a convenient means of measuring the effects of drying on carotenoid stability during subsequent storage. It has been reported that ethoxyquin does not improve the excellent storage stability of freezedried alfalfa meal (Knowles et al, 1968). However, ethoxyquin markedly improved carotenoid stability in the freezedried concentrate (Figure 1).…”