STABILITY OF LIPIDS OF INDIAN MACKEREL TO GAMMA IRRADIATION

The effect of gamma irradiation (1.5 and 2 kGy) on the lipids of Indian mackerel (Rastrelliger kanagurta) stored at 0–2C was studied. No major differences in lipid composition of fish was observed as a result of irradiation and subsequent storage for up to 14 days. However, higher carbony I values in irradiated samples during the initial storage of fish was revealed. Irradiation also had no adverse effect on the nutritionally important omega-3 polyunsaturated fatty acids (PUFA) of the fish.     

园艺产品辐照技术的应用研究进展

综述了园艺产品辐照技术的应用现状，并指出除了在现已应用的领域，园艺产品辐照技术还将在珍奇花卉保鲜、杀灭检疫性病虫害、轻加工果蔬保鲜、园艺产品加工工艺的改进、杀灭果蔬食品中携带的致病菌等几方面表现出它独特的应用价值。     

EFFECTS ON THE ALKALOID CONTENT OF POTATOES GROWN FROM SEEDS SUBJECTED TO LOW-DOSE GAMMA IRRADIATION

SUMMARY— Effects of low dose gamma irradiation of seeds on alkaloid content, proximate composition and yield of the potato tubers were studied. Increase in yield with irradiation of seeds was inconclusive. Changes in proximate composition of Russet potatoes grown from tubers irradiated at 1,500 rads were found to be insignificant. Varietal differences in solanine content were more pronounced than those due to gamma irradiation. In all cases the solanine content in potatoes grown from irradiated seeds was found to be far below the toxic level for human beings.     

EFFECT OF GAMMA IRRADIATION ON THE POSTHARVEST PHYSIOLOGY OF FIVE BANANA VARIETIES GROWN IN INDIA

ABSTRACT— Gamma irradiation to 20–40 krad inhibits the ripening changes in preclimacteric bananas without affecting the fruit quality. Both fruit maturity at harvest and post-irradiation storage temperature markedly influence the response to irradiation. The optimum dose and the maximum tolerable dose varied among the five varieties screened. Ability of the banana fruit to withstand higher doses of gamma irradiation depends on the physiological status of the fruit at time of irradiation. Irrespective of varietal differences, irradiation of preclimacteric bananas to doses above 50 krad resulted in severe skin discoloration and fruit splitting. Irradiation under anoxia did not markedly reduce the radiation injury, suggesting that factors other than ozone formed during irradiation in air may contribute the radiation damage. Fruits on the climacteric could tolerate up to 200 krad but no effect on ripening rate was observed. Ethylene or 2,4-D could reverse irradiation-induced inhibition of ripening in bananas. Irradiation seems to decrease the sensitivity of banana fruit to the ripening action of exogenously added ethylene.     

我国花卉食品的开发利用及展望

花卉食品的开发利用综述，并提出展望，为进一步开发利用花卉资源作参考。     

COMPUTER EVALUATION OF IRRADIATION PROCESSES IN CYLINDRICAL CONTAINERS WITH GAMMA SOURCES

SUMMARY —A numerical technique is presented for evaluating food irradiation processes using cylindrical gamma sources. Dose rate distributions obtained by dividing a container into finite concentric rings permit the use of a nonuniform initial spore load distribution and the determination of both number and distribution of survivors. The double integral giving dose rates was computed using several methods. The computations gave survivors significantly different from those obtained by using approximations given in literature. Accurate evaluations require utilization of dose rate distributions in radial and axial directions.     

EFFECT OF GAMMA RAY IRRADIATION AND FRYING ON THE THIAMINE CONTENT OF BACON

The effects of ionizing irradiation and frying on the thiamine and riboflavin content of bacon were determined. Significant destruction of thiamine but not riboflavin occurred during both the irradiation and frying. The destruction of thiamine was found to be directly related to the dose of ionizing radiation or the degree of cooking. Frying before irradiation, reduction of water content by lyophilization, and irradiation at - 40°C rather than 2°C produced significantly greater retention of thiamine. Frying the bacon following irradiation produced radiation dose-related, nonadditive, increased destruction of thiamine. The protective effect of frying before irradiation was not directly linked with the reduction of moisture by frying.     

GAMMA IRRADIATION IMPROVED THE QUALITY OF ONION FLAKES USED BY ARGENTINE CONSUMERS

A study was carried out on the microbiological status of local and imported packed onion flakes available at retail markets in Argentina. The effectiveness of selected doses of gamma irradiation to decontaminate imported onion flakes and the effects of irradiation on some technological properties were also investigated. Imported onion flakes were contaminated with a high percentage of spore‐forming microorganisms. Imported onion flakes were irradiated at doses of 7, 9, 11, 15, 18 and 23 kGy, and stored at temperatures between 20 and 25C, and relative humidities ranging from 50 to 80%. Irradiation doses between 7 and 11 kGy reduced the aerobic plate count by three log cycles. Doses between 7 and 15 kGy reduced yeast and mold counts by two log cycles. A dose of 7 kGy was sufficient to reduce the sulfite‐reducing Clostridia count to less than detectable levels. We concluded that a dose of at least 7 kGy was necessary to decontaminate imported dry onion marketed in Argentina. No variation in water content or water activity was attributed to selected irradiation doses. Irradiation in the 7–11 kGy range markedly increased the saline extract optical index of imported onion flakes. Gamma irradiation did not significantly affect the flavor intensity as determined by enzymatic production of pyruvic acid.     

低过敏性海产食品的研究

综述了引起海产品过敏主要的过敏原及其特征，阐述了海产食品过敏原性的研究进展以及面临的困难和存在的问题，对低过敏性海产食品的开发途径进行了展望，为我国海产食品的深加工提供一定的参考。     

EFFECT OF GAMMA IRRADIATION ON THE LIPID PEROXIDATION IN CHICKEN, LAMB AND BUFFALO MEAT DURING CHILLED STORAGE

Chicken, lamb and buffalo meat were subjected to low-dose gamma irradiation (2.5 kGy) and stored at 0–3C. Lipid peroxidation in terms of thiobarbituric acid (TBA) number and carbonyl content were monitored during storage. While irradiated meat showed slight increase in TBA number and carbonyl content on storage as compared to nonirradiated meat, this did not affect the sensory qualities of meat. Free fatty acid content decreased markedly on irradiation. Irradiated meats were microbiologically safe and sensorily acceptable up to 4 weeks in the nonfrozen state (0–3C) while nonirradiated meat had a shelf-life of less than 2 weeks .     

THEORETICAL EVALUATION OF COMBINED IRRADIATION AND THERMAL PROCESSES IN CYLINDRICAL CONTAINERS WITH GAMMA SOURCES

SUMMARY —A digital computer technique is presented for studying combined effects of heat and radiation in food sterilization, using steam retorts and cylindrical gamma sources. Temperature and dose rate distributions in cylindrical containers are computed using numerical methods. Distributions due to preliminary treatments–survivor and degree of spore sensitization–are inputs to subsequent treatment. The heat-radiation sequence was studied using data available, which indicates no synergism. This additive combination served as control to demonstrate synergism for radiation-heat sequence. Synergy, as influenced by irradiation exposure time, source strength, thermal process time and retort temperature was studied.     

EFFECTS OF GAMMA IRRADIATION OF BARLEY AND MALT ON MALTING QUALITY

Two two-rowed barley cultivars, Tokak and Clerine, were irradiated at two different dose ranges (0.05–0.75 kGy and 0.5–5.0 kGy) using a ⁶⁰Co source. Irradiation of barley at the medium levels before malting had detrimental effects on most of the malt quality criteria. The detrimental effects of irradiation was lower at doses up to 0.25 kGy. Irradiation of malt samples caused either slight or no deterioration of quality characteristics .     

THE ELIMINATION OF ENTERIC BACTERIAL PATHOGENS FROM FOOD AND FEED OF ANIMAL ORIGIN BY GAMMA IRRADIATION WITH PARTICULAR REFERENCE TO SALMONELLA RADICIDATION1

Despite world-wide severe underreporting of food-transmitted disease of microbial origin, it is clear that the majority of such diseases is caused by enteropathogenic Enterobacteriaceae. Most of these are spread by foods of animal origin, consumed raw, or recontaminated subsequent to industrial or culinary heat processing. Radicidation with the help of gamma rays of carcasses or consumer size cuts presents a real solution to this problem. An ecologically based procedure for the estimation of the most probable effective dose for the elimination of enteric pathogens of bacterial origin from fresh meats, poultry and seafoods is described, special attention being paid to bacteriological analytical methodology found useful under conditions of practice. An additional advantage of this approach is, that it will allow easy assessment of lower doses, following reductions of initial enterobacterial loads, which should be attempted in parallel. It is demonstrated that most alleged counter-indications so far hampering the use of ionizing radiation in food processing have now been eliminated, allowing full advantage to be derived from radicidation as an essential contribution to the protection of the consumer against diseases of microbial aetiology spread by foods, similar to the mandatory pasteurization of milk.     

THE FUTURE OF MILK DISTRIBUTION IN THE UK

The changes in the pattern of milk distribution since the 1930s are sketched, including the incidence of 'other goods' sales. Changes brought about by the supermarket era and the permanent problem of labour shortage and ability were illustrated, with some comments on the difficulties of the present 'throw-away' glass age. It is suggested that the maintenance of doorstep delivery is of great importance to the industry and this will be helped by the delivery of refrigerated milk in non-returnable containers throughout the year.