Safety evaluation of sweet lupine (Lupinus albus cv. Multolupa). II. Nine-month feeding and multigeneration study in rats

Nutrient bioavailability of white lupine in complete feed for non-human primates

The article is devoted to the current world problem of vegetable protein deficiency, the solution of which can be white lupine. Particular attention is paid to assessing the bioavailability of nutrients from white lupine (Lupinus albus) in the body of non-human primates M. Mulatta. Because primates are phylogenetically closer to humans than other laboratory animals, which is very convenient for modeling and studying the digestibility of nutrients in diets. The purpose of the article is to study the digestibility of nutrients in lupine in the structure of complete feed and its effect on the biochemical parameters of the blood. As a result of the research, it was found that the inclusion of white lupine in the structure of the diet allows to improve the bioavailability of nutrients of complete feed, when included in the structure of the diet of white lupine in an amount of 10%, it made it possible to improve the digestibility of crude protein in relation to the control group by 5.5%, crude fat by 0.99%, crude fiber by 1.84%, BEV by 7.99%, crude ash by 4.67%, calcium (Ca) and phosphorus (P) by 6.99%, and 1.02 %. With the inclusion of 20% white lupine in the structure of the diet, it made it possible to improve the digestibility of crude protein in relation to the control group by 9.28%, crude fat by 6.5%, crude fiber by 5.98%, BEV by 2, 78%, crude ash by 11.28%, and absorption of calcium (Ca) and phosphorus (P) by 9.93% and 8.68%. At the same time, the results of hematological analyzes generally indicate the safety of consuming white lupine for 35 days.

Scientific opinion on the risks for animal and human health related to the presence of quinolizidine alkaloids in feed and food, in particular in lupins and lupin-derived products

The European Commission asked EFSA for a scientific opinion on the risks for animal and human health related to the presence of quinolizidine alkaloids (QAs) in feed and food. This risk assessment is limited to QAs occurring in Lupinus species/varieties relevant for animal and human consumption in Europe (i.e. Lupinus albus L., Lupinus angustifolius L., Lupinus luteus L. and Lupinus mutabilis Sweet). Information on the toxicity of QAs in animals and humans is limited. Following acute exposure to sparteine (reference compound), anticholinergic effects and changes in cardiac electric conductivity are considered to be critical for human hazard characterisation. The CONTAM Panel used a margin of exposure (MOE) approach identifying a lowest single oral effective dose of 0.16 mg sparteine/kg body weight as reference point to characterise the risk following acute exposure. No reference point could be identified to characterise the risk of chronic exposure. Because of similar modes of action for QAs, the CONTAM Panel used a group approach assuming dose additivity. For food, the highest mean concentration of Total QAs (TotQAs) (i.e. the 6 most abundant QAs) was found in lupin seed samples classified as 'Lupins (dry) and similar-'. Due to the limited data on occurrence and consumption, dietary exposure was calculated for some specific scenarios and no full human health risk characterisation was possible. The calculated margin of exposures (MOEs) may indicate a risk for some consumers. For example, when lupin seeds are consumed without a debittering step, or as debittered lupin seeds high in QA content and when 'lupin-based meat imitates' are consumed. For horses, companion and farm animals, other than salmonids, the available database on adverse effects was too limited to identify no-observed-adverse-effect levels and/or lowest-observed-adverse-effect levels and no risk characterisation was possible. For salmonids, the CONTAM Panel considers the risk for adverse effects to be low.

Toxicological studies on plant proteins: a review

Nowadays, toxicological studies are contributing to human health more than ever. Reports on the toxicological studies of plant proteins, which are continuously growing in number in the literature, have been reviewed. Two important aspects are discussed: dietary safety evaluation, including toxicity tests and the maximum daily intake allowance, and the appropriate proportion in our daily diets of proteins from traditional foods and of new proteins from plant sources not traditionally employed as foods. Water hyacinth leaf proteins, sweet lupin proteins and canola proteins have not been shown to be toxic, although they are not traditionally employed as food proteins. These findings are very important for exploiting valuable new protein sources that are suitable for human or animal consumption and applicable to the food industry. Acutely toxic proteins, including lectins, ribosome-inactivating proteins, inhibitors of proteolytic enzymes and glycohydro-lases, have been isolated from plant materials and identified. Their toxicities and molecular characteristics have been described. The toxicity of proteins depends upon their specific native structures. Once they are denatured by appropriate treatment, such as heating, their toxicity can be reduced or even eliminated. These findings indicate that raw materials that contain this kind of toxic protein are not edible. However, after proper processing, they may be suitable for human or animal consumption. Although the toxicities of type 2 ribosome-inactivating proteins reported by different authors vary, the maximum dosages are still trace amounts.

The bioavailability and postprandial utilisation of sweet lupin (Lupinus albus)-flour protein is similar to that of purified soyabean protein in human subjects: a study using intrinsically15N-labelled proteins

Sweet lupin (Lupinus albus), a protein-rich legume devoid of anti-nutritional factors, is considered to have a high potential for protein nutrition in man. Results concerning the nutritional value of lupin protein are, however, conflicting in animals and very scarce in human subjects. Furthermore, where fibre-rich protein sources are concerned, the long-term nutritional results are often obscured, particularly since fibre-promoted colonic fermentation may bias the energy supply and redistribute N flux. We therefore studied, during the postprandial phase, the bioavailability and utilisation of lupin-flour protein in nine healthy men who had ingested a mixed meal containing intrinsically15N-labelled lupin flour as the protein source (Expt 1). The real ileal digestibility (RID) and ileal endogenous N losses (IENL) were assessed using a perfusion technique at the terminal ileum, and the N content and15N enrichment of ileal samples. Lupin flour exhibited a high RID of 91 (SD 3) % AND LOW IENL (5·4 (sd 1·3) mmol N/h). Postprandial dietary deamination was also assessed from body dietary urea and urinary dietary N excretion, and compared with results in nine healthy men following an isoenergetic meal containing a15N-soyabean-protein isolate with a similar RID, as a control (Expt 2). Postprandial dietary deamination was similar after lupin and soyabean meals (17 (sd 2) and 18 (sd 4) % ingested N respectively). We therefore conclude that lupin protein is highly bioavailable, even if included in fibre-rich flour, and that it can be used with the same efficiency as soyabean protein to achieve postprandial protein gain in healthy human subjects.

Quantitative sandwich ELISA for the determination of lupine (Lupinus spp.) in foods

The use of lupine in foods has increased considerably during the past decade, reflected by a corresponding increase in reported lupine-induced allergic incidents. Lupine allergy may arise either by primary sensitization or by clinical cross-reactivity in peanut-allergic persons. Detection of lupine proteins in food has previously been based on the use of patient serum. A novel sandwich enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of lupine in processed foods was developed, using a polyclonal rabbit antilupine capture antibody and a biotinylated conjugate of the same antibody for detection. The antibody was highly specific for lupine, apart from minor cross-reactivities to other legumes. The assay had a detection limit of 1 mug/g and was successfully used to quantify lupine protein in various food matrixes. Recoveries ranged from 60 to 116%, while the intra-and interassay coefficients of variation were <6% and <21%, respectively.

Adverse effects of dietary lupine in broiler chickens

This study describes the adverse effects of dietary lupines in broiler chickens for which lupine seeds (Lupinus angustifolius) in raw, dehulled, or autoclaved forms were used as a replacement for soybean meal (SBM) in practical diets. Test diets contained 35% SBM (control) or raw (40%), autoclaved (40%), or dehulled (35%) lupine seed meal. All diets were isocaloric (3,230 kcal/kg AME) and isonitrogenous (23% crude protein). Each diet was offered ad libitum to a group of 16 (four replicates with four birds per replicate) day-old male broiler chicks for 21 d. Chemical analysis of lupine seeds showed no detectable levels of mycotoxins, and total alkaloid contents were below 0.01%. Decreased food intake and growth rate were the main signs observed in all birds fed lupine-based diets. These adverse effects were observed during the first week and persisted throughout the trial. Acute signs of toxicity were observed in four chicks fed the diet containing raw lupine seed during the first week of exposure. Initial clinical signs included leg weakness, lack of coordination, and torticollis. In later stages, during Weeks 2 and 3, some birds fed lupine-based diets showed signs of muscle paralysis and skeletal deformity. Postmortem examination did not show gross pathological changes associated with the dietary treatments. Liver microsomal cytochrome P-50 content was higher (P < 0.05) in birds fed the raw lupine-based diet (mean 0.56 pmol/mg protein) in comparison with controls (mean 0.25 pmol/mg protein), which indicated a systemic effect. Based on the present results, it can be stated that high levels of some varieties of sweet lupines in broiler diets may cause significant adverse effects manifested as 1) decreased feed intake and growth rate in most of the birds, and 2) specific signs of acute and chronic toxicity in some individuals.

A 90-day feeding study of the alkaloids of Lupinus angustifolius in the rat

Groups of 20 Sprague-Dawley rats of each sex were fed diets containing lupin alkaloid at dose levels of 0, 100, 330, 1000 and 5000 ppm supplemented with maltodextrin to attain a level of 4.5%, for 13 wk (equivalent to average daily intakes of lupin alkaloid of approximately 0, 10, 30, 100 and 500 mg/kg body weight/day, respectively, over the course of the study). A further group of rats was fed control (basal) diet over the same period. All control and high-dose animals underwent an ophthalmological examination before the start of the study and before autopsy. Blood samples were collected from all rats prior to the start of treatment, during wk 6 and prior to autopsy for haematological and clinical chemistry examination. All animals were monitored daily for change in clinical condition, and body weight and food intake were measured twice weekly. A range of tissues were preserved for histological examination at autopsy. There was an initial drop in food intake by all rats in the 1000 and 5000 ppm groups and thereafter the intake was between 90% and 95% of that of the controls. In general, no other effects related to treatment were seen. On the basis of the lower body weights and food intakes of the groups fed the alkaloid at levels of 1000 and 5000 ppm, a no-observed-adverse-effect level (NOAEL) of 330 ppm is seen under the conditions of this study. It is likely that these effects are entirely due to the antipalatability effect of the lupin alkaloids. In view of the growth rates, haematology, clinical chemistry and histological findings, a speculative NOAEL of 1000 ppm may be more appropriate.

A 90-day feeding study of lupin (Lupinus angustifolius) flour spiked with lupin alkaloids in the rat

Three groups of 20 male and 20 female Sprague-Dawley rats were given diets based on lupin (Lupinus angustifolius) flour (55.4 g/100 g diet) that had been spiked to provide dietary concentrations of 250, 1050 or 5050 mg lupin alkaloids/kg diet. A control group of 20 males and 20 females received 50 mg/kg (derived from the background level of alkaloid in lupin flour). The rats were treated for a minimum of 90-98 days. A dose-related reduction in red blood cell count and haematocrit (HCT) occurred in both sexes after 45 days, and the mean cell volume (MCV) was decreased in all the male treatment groups. The reductions in HCT and MCV persisted in the males until termination of the study when decreased haemoglobin levels were also observed in the top-dose males. The relative liver weights of female rats showed a dose-related increase. Altered foci of liver parenchymal cells were seen in five females receiving dietary levels of 5050 mg/kg, in one female fed 250 mg/kg and in one male from each of the 250 mg/kg and 1050 mg/kg treatment groups. No foci were seen in the control group. Basophilic foci are uncommon in young rats suggesting that the low incidence in this study is compound related.