Nutrient composition and bioavailability of protein and energy in common fruits and vegetables prepared for human consumption

Growing rats were used as animal model to evaluate the digestibility of energy and protein digestible corrected amino acid score (PDCAAS) in some common fruits and vegetable grown during two subsequent growth seasons in different cultivation systems. The ingredients were cultivated by each of three different farming strategies: LIminusP: low input of feritlizer without pesticides, LIplusP: lowinput of fertilicer and high input of pesticides and LHplusP: high input of fertilizer and high input of pesticides. The protein quality of the dietary ingredients gave rise to the following ranking: apples, carrots, potatoes, kale and peas. The amino acid pattern in peas and potatoes complemented each other fairly well as dietary sources, while lysine turned out to be the limiting amino acid in both carrot and kale. Years, but not cultivation system influenced the protein and amino acid content of the foods

Preference of organic grown carrorts in a rat model

Food preference tests represent an approach in food quality research, taking advantage of the instinctive feeding behavior of animals by allowing them to choose between food samples. A great number of investigations using laboratory rats concerning essential and/or dangerous contents are based on this method and have shown its effectiveness. The selection of food is influenced to some degree by smell and taste, but mostly by wholesomeness and need. In the present study a preference test was used in order to test eventual selective differences among rats with regard to same composition, but cultivated in three different systems. The experimental diets were formulated to meet the NRC requirements for rats by mixing 40% of freeze dried carrots with an Altromin chow diet. The carrots were from a 2-year field study. The carrots were grown by three different cultivation strategies: one conventional (C) and two organic systems (OA, organic using animal manure; and OB, organic using cover crops). Wistar female rats (N=30, 15 per year) weighing 230 g, were kept individually in cages, and were arranged in a block design with three blocks of 5 rats. For 5 days, each rat had free access to each of the three kinds of diets (C, OA, OB), and consumption of feed from each of the diet-troughs was measured every day. Thereafter, the rats were offered an ordinary rat chow until the preference test was repeated 2 weeks later. Preferences expressed by daily food-intake were analyzed statistically taking into account the correlations of the choices of a rat per experimental day, and over the course of the experiment. The overall conclusion of the study is that rats show individual preference for the test diets, and that no clear difference among the dietary treatments could be obtained

Organic diets and physical activity: Research experience using a rat model

Total energy expenditure or heat production is comprised of basal metabolic rate, thermic effect of food, and physical activity. Physical activity is the most variable and easily altered component of total heat production. Physical activity is influenced by a number of biological parameters i.e. diet, genetics, age, and gender. The diet components of the macro as well as micronutrients and other components (secondary metabolites) associated with a diet could contribute to the well being of the animal and cause variation in physical activity. In order to investigate physical activity as a parameter to differentiate diets based on conventional or organic grown carrots the total heat production and physical activity was measured in a rat model. The experimental diets were formulated to meet the NRC requirements for rats by mixing 40% of freeze dried carrots with an Altromin chow diet. The carrots were from a 2-year field study. The carrots were grown by three different cultivation strategies: one conventional (C) and two organic systems (OA, organic using animal manure; and OB, organic using cover crops). The diets were given to weaned female GKMol rats, in groups of five rats per diet and given their assigned diet, for approx. 2.5 months. Throughout the experimental period the rats were monitored and weighed each week. The rat’s heat production and physical activity was measured with two open-air circuit respiration chambers, and measurement was done on a group of 5 rats. In the chamber the rats were placed in individual cages. The activity was measured using both passive infrared detectors and with video recording. There was not surprisingly lower physical activity level of rats during the day. Being night-active animals, rats are usually resting during the day-time

Sundhedseffekt af øko-gulerødder?

Høstår og mark har større betydning end produktionsmetoden hvad angår gulerødders sundhedseffekt målt i en rottemodel

Er økologiske gulerødder sundere end konventionelt dyrkede?

Øger økologiske dyrkningsmetoder kvaliteten af gulerødder, og har indtagelsen af dem en positiv indflydelse på sundhedsmarkører målt i en rottemodel? Det er en af de hypoteser, som forskere ved DJF forsøger at besvare i et igangværende forskningsprojekt

Carbohydrate and lipid composition of vegetables, and bioavalability assessed in a rat model: Impact different cultivation systems

Environmental as well as cultivation factors may greatly influence the chemical composition of plants. The main factors affecting chemical composition of foodstuff is level and type of fertilizer (conventional and organic cultivation systems), location or soiltype and year of harvest. Organic foods are defined as products which are produced under controlled cultivation conditions characterized by the absence of synthetic fertilizers and very restricted use of pesticides. Dietary carbohydrates constitute a major fraction of most feedstuffs and can be divided according to glycosidic linkage into sugars (mono- and disaccharides), oligosaccharides, starch and non-starch polysaccharides (NSP). The bulk of disaccharides and starch will be broken down by the action of pancreatic and mucosal enzymes in the small intestine, while there are no enzymes capable of cleaving some types of oligosaccharides and NSP. A fraction of starch (resistant starch) may also pass the small intestine undegraded either because the starch is physically inaccessible, the starch has a structure that resist amylolysis or the starch is retrograded after heat treatment. Lignin is not a carbohydrate but is tightly associated to cell wall polysaccharides. The term dietary fibre (DF) is used for cell wall and storage NSP and lignin. Adequate intake of dietary fibre are generally accepted as linked to health benefit into a protective role in large bowel cancer, diabetes, coronary heart disease and the issue of faecal bulking. Linoleic (C18:2 n-6) and α-linolenic (C18:3 n-3) are essential fatty acids, which cannot be synthesized in the mammalian organism, and therefore must be supplied in the diet of animals and man. These fatty acids are precursors for the important longer chain higher polyunsaturated fatty acids of the n-6 and n-3 families. Although fats are essential part of the diet, but if consumed in excess, they may exert negative effects on human weight change. Potatoes, carrots, peas, green kale, apple, and rapeseed were grown by three different cultivation strategies, i.e. organic (ORG), conventional (CON), or semi-organic (ORG+) farming system. Each ingredient was treated as for application for human consumption: potatoes, mature, soaked peas and kale were boiled and raw carrots and apples were shredded, and the food was then freeze-dried and packed into airtight bags. Rapeseed oil was produced from the air-dried rapeseeds of the three cultivation treatments, and the residual was discarded. The carbohydrate fraction of the ingredients except rapeseed oil was analysed into: starch, sugars, oligosaccharides and all its constituents and lignin. Likewise the dietary lipids of all ingredients were extracted and the long-chain fatty acids determined by GLC. The ingredients were mixed with a standard synthetic mixture and were formulated to meet the NRC requirements for rats and used in a balance experiments for measuring the bioavalability of the ingredients. Carbohydrate and lignin were predominant dietary constituents with value from 584 g/kg DM in kale to 910 g/kg DM in potatoes. Triacylglycerol was the major lipid class in pea with 82 % of total fatty acids in contrast to apple with only 35 % of fatty acids of the ether extract

Rats show individual preference for short-term choice of three human diets

A preference test was conducted to investigate whether rats could distinguish among three iso-energetic and iso-nitrogeneous human diets prepared with ingredients cultivated by each of three different farming strategies: LIminusP: low input of feritlizer without pesticides, LIplusP: lowinput of fertilicer and high input of pesticides and LHplusP: high input of fertilizer and high input of pesticides. The experimental diets were formulated to meet the NRC requirements for growing rats by mixing potatoes, carrots, peas, green kales, apples, and rapeseed oil. For five days, rats (N=27) had free access to each of the three diets, and consumption of each of the diets was recorded daily. Thereafter, rats were offered a standard laboratory chow until the test was repeated. The results indicated that the majority of the rats showed individual preference for the diets and behaved similarly on different experimental days (ρ = 0.63 in repetition 1 and ρ = 0.73 in repetition 2) and in the two repetitions (τ = 0.79). However, no clear difference among the dietary treatments could be obtained

USE OF A RAT MODEL TO ELUDICATE IMPACT OF ORGANIC FOOD ON HEALTH

Ingredients (potatoes, carrots, peas, green kale, apples, and rapeseed oil) were grown according to three different cultivation systems (“Organic”, low input of fertilizer without pesticides; “Minimally fertil-ised”, low input of fertilizer and high input of pesti-cides, “Conventional”, high input of fertilizer and high input of pesticides). Three iso-energetic and iso-nitrogeneous diets were composed of equal propor-tions of the ingredients originating from each of the cultivation systems, and the diets were investigated with respect to several physiological responses and biomarkers of health using a rat model. In addition, the diets were tested in a food preference test using the same type of rats, but another generation. In both experiments, the diets were optimized according to the nutritional requirements of reproducing rats, except for a high content of fat. Most of the measured variables (biomarkers of health) showed no differ-ences between the experimental diets, however, some differences between dietary treatments were obtained, which were in favour of the “organic” diet contrasted with the “conventional” diet. The prefer-ence test showed a significant interaction between diet choice and mother’s diet. However, the results obtained from the present study cannot be extrapo-lated to all organic and conventional cropping sys-tems, mainly because crops were grown only in one replication. Thus, it is of outmost importance that future investigations on the effect of organic food in relation to human health and well-being should be based on well-defined and controlled food produce system with replication

Performance and diarrhoea in piglets following weaning at seven weeks of age: Challenge with E. coli O 149 and effect of dietary factors

Four dietary factors (ad libitum versus feed restriction, control versus protein restriction at ad libitum feeding, control versus inclusion of lupine as a protein source at ad libitum feeding, and control versus extra vitamin E at ad libitum feeding) were tested in four separate experiments for the effect on diarrhoea. To introduce a diarrhoea-like condition, half of the piglets were challenged with an inoculation of an E. coli O 149 dose of 1 x 108 colony forming units on day two and three after weaning (day of weaning = day one). All piglets were susceptible since the dams were tested mono-zygotic susceptible to the attachment site of E. coli O 149 in the intestines. Each of the four experiments included 32 piglets from 4 sows. The design was 2 x 2 factorial with dietary factor and E. coli O 149 challenge as the two factors, each at two levels. The piglets were housed individually during the experiment which lasted for 10 days from weaning at 7 weeks of age. The daily recordings included feed intake, weight and faeces score (from 1 = firm and solid to 6 = yellow and watery). Faeces from days 2 to 5 were tested for E. coli strains. In addition, blood was sampled and serum was analysed for E. coli antibodies, IgG and IgM. Generally the E. coli challenge had no effect on growth and feed intake whereas faeces score and number of faeces haemolytic bacteria increased and faeces dry matter decreased. Feed restriction decreased the weight gain while faeces characteristics were unaffected. An analysis including all four experiments revealed that a feed intake of less than 200 g day one after weaning seems to be associated with a relatively high incidence of a post-weaning diarrhoea-like condition. Protein restriction decreased faeces score and increased faeces dry matter while weight gain tended to decrease. Inclusion of lupine affected neither weight gain nor faeces characteristics. Extra vitamin E did not affect weight gain while faeces dry matter decreased, and faeces score and number of faecal haemolytic bacteria increased. The dietary treatments had no effect on the immunological responses. In conclusion, the studied dietary factors could not alleviate a diarrhoea-like condition and at the same time maintain the growth rate. Furthermore, the results indicate that performance can be improved if piglets achieve a daily feed intake of at least 200 g from day one after weaning