Formulation of a nasogastric liquid feed and shelf-life extension using gamma radiation.

Nasogastric liquid feed formulation (NGLF) was developed for immunocompromised patients who are vulnerable targets of pathogenic assault. NGLF consisted of cereals, pulses, vegetables, and milk powder to provide balanced nutrients; however, the shelf life was only a few hours because this product was highly prone to microbial contamination and proliferation due to its high water content and rich nutrients. Postpreparation storage and distribution was very difficult, even at chilled temperatures. To overcome this problem, the NGLF was irradiated at various doses (2.5 to 10 kGy). Gamma irradiation at 10 kGy reduced the microbial load to nondetectable levels, and the product could be stored up to 1 month without any detectable increase in microbial load. The sensory evaluation did not indicate differences between the nonirradiated fresh, irradiated fresh, and stored samples. Nutritional quality in terms of total carbohydrates, dietary fiber, proteins, calories, vitamins A and C, and the micronutrients calcium, iron, and zinc was not affected by irradiation. NGLF also possessed antimutagenic potential against ethylmethanesulphonate-induced mutagenesis in Escherichia coli cells as evaluated by the rifampin resistance assay. This property of NGLF remained unchanged even after exposure to a 10-kGy dose of gamma radiation. Thus, irradiated NGLF seemed to be a safe and wholesome food for immunocompromised patients.

Shielding parenteral nutrition from light: does the available evidence support a randomized, controlled trial?

BACKGROUND: Exposure of total parenteral nutrition to ambient light induces the generation of peroxides, creating oxidant stress, which potentially compounds complications of prematurity. Photograph protection of total parenteral nutrition reduces the peroxide load and has been shown to be associated with nutritional and biochemical benefits in animals and humans. It is unclear whether this reduction in peroxides from total parenteral nutrition leads to a reduction in the complications of prematurity, such as bronchopulmonary dysplasia. Our hypothesis was that shielding total parenteral nutrition from ambient light is linked to clinical benefits. OBJECTIVE: The purpose of this work was to determine whether photograph protection of total parenteral nutrition (light protected), as compared with no photoprotection (light exposed), reduces the occurrence of bronchopulmonary dysplasia or death in preterm infants. METHODS: The Canadian Neonatal Network provided data for infants born in 2006 at <28 weeks' gestation admitted to level 3 NICUs in Canada. A retrospective analysis was performed comparing bronchopulmonary dysplasia and death in infants who received light-exposed or light-protected parenteral nutrition. Data were analyzed by using logistic regression models. RESULTS. Thirteen NICUs offered partial light-protected (total parenteral nutrition bag only, intravenous tubing exposed) and 13 offered light-exposed parenteral nutrition; not a single NICU offered complete light-protected parenteral nutrition (total parenteral nutrition bag plus intravenous tubing). The incidence of bronchopulmonary dysplasia or death was 66% with light-protected (n = 428) vs 59% with light-exposed (n = 438) parenteral nutrition. CONCLUSIONS: Partial photograph protection of total parenteral nutrition was not associated with a reduction in bronchopulmonary dysplasia or death as compared with no photograph protection; this relationship is confounded by covariates with strong associations with bronchopulmonary dysplasia. Partial photograph protection of total parenteral nutrition solutions confers no clinical benefit, while consuming valuable resources. A randomized, controlled trial is justified to determine whether there is a true "cause-and-effect" relationship between complete photoprotection of total parenteral nutrition and bronchopulmonary dysplasia or death.

[Evaluation of the nutritive value of soybean milk prepared with microwave-treated soybeans]. / Evaluación del valor nutricional de leches de soya preparadas a partir de granos de soya tratados con microondas.

Aqueous soybean extracts were prepared from beans, previously treated by microwaves to almost inactivate their lipoxygenase. These soy milks thus obtained were then nutritionally evaluated. All soy milks studied showed lower protein, fat, ash and total solids contents, as compared to a control milk prepared from soy beans not processed by microwaves. The milk obtained from soybeans with 8.7% initial moisture, treated by microwaves for 240 seconds, had the best total chemical score and the highest apparent methionine availability, as well as PER. The complete inactivation of the trypsin inhibitor activity was achieved with the milk prepared from soybeans with 56.8% initial moisture, subjected to microwave treatment for 180 seconds. On the other hand, the milk obtained from soybeans with 38.8% initial moisture, processed by microwaves for 180 seconds, resulted to have the highest, in vitro, protein digestibility.

The oxidation of benzo[a]pyrene mediated by lipid peroxidation in irradiated synthetic diets.

The effect of gamma-irradiation (1000-4000 Gy) on the formation of lipid peroxides and on the oxidation of the environmental carcinogen benzo[a]pyrene (BP) has been studied in mixtures of starch/fat and BP which were used as models for natural foods. When mixtures containing polyunsaturated fats (mackerel oil and cod-liver oil which contain relatively large proportions of C20:5 and C22:6) were exposed to gamma-irradiation, large concentrations of lipid peroxide were formed and a concomitant oxidation of BP to mutagenic and toxic BP quinones took place. The rate of BP oxidation was closely related to the extent of peroxidation of the lipids in the starch mixtures and was dependent on the dose of gamma-irradiation and the presence of air. Mackerel oil also underwent peroxidation during the storage of both irradiated and unirradiated starch/mackerel oil/BP mixtures and this resulted in a significant oxidation of the BP present in these samples. Antioxidants such as vitamin E and BHA inhibited both lipid peroxidation and BP oxidation resulting from gamma-irradiation. These results demonstrate that the species generated during the peroxidation of unsaturated fats in foodstuffs can react with polycyclic aromatic hydrocarbons such as BP and convert them into active mutagenic and toxic products. This has important toxicological implications, particularly as the consumption of polyunsaturated fat in the Western world is increasing and gamma-irradiation may soon be widely used for food sterilization.

[Problem of using dehydrated food products in long-term space flights]. / K probleme ispol'zovaniia obezvozhennykh pishchevykh produktov v dlitel'nykh kosmicheskikh poletakh.

The paper discusses the results of five studies on 35 test subjects conducted to test diets of dehydrated products to be used in prolonged space flights. The studies have demonstrated that a diet consisting of only dehydrated food products can be used for a prolonged time (up to 1 year). Dehydrated foods after a 2-year storage and proton irradiation at a dose of 24,000 rad retain their biological value and assure an adequate nutritional status. On this basis a space diet composed of dehydrated foods has been developed.

Interactions between Maillard's reaction products, the microflora of the digestive tract and mineral metabolism.

3 p. 100 of Maillard's reaction products (MRP), obtained by mild heating of glucose and glycine, were added to a semi-synthetic diet sterilized by irradiation. This resulted in increased dry matter excretion, more marked in axenic than in holoxenic rats, and in reduced apparent absorption of sodium and potassium in holoxenic rats. The addition of these products caused diarrhoea in axenic animals, thus preventing a good estimation of apparent absorption. It led to a significant decrease in the retention of calcium, phosphorus, magnesium and copper only in the axenic rats. It is shown that MRP affect mineral metabolism and that the microflora plays a protective role in the physiology of digestion.

Variations of bile salt pool size and secretion rate in rats according to the modes of sterilization and preparation of a semi-synthetic diet.

A semi-synthetic diet was sterilized by irradiation and given to rats as pellets, powder or paste obtained by admixing an equal amount of water. The bile salt pool increased from the first to the third treatment. That effect disappeared when the starch was replaced by sucrose or when the diet was autoclaved instead of irradiated. The bile duct secretion of bile salts varied according to the bile salt pool. Hypotheses are proposed to explain the relationship between the form of the diet and bile salt pool size and secretion.