In a preliminary test, 16 male volunteers tasted samples of a soup with graded doses of red pepper in order to define a moderate and a maximum tolerable dose of red pepper.
On the day of the experiment, the researchers gave all volunteers the same breakfast. At lunchtime, the subjects ingested one of four experimental soups containing either a placebo, a moderate or a strong dose of red pepper plus placebo capsules, or a placebo soup plus capsules delivering a strong dose of red pepper.
The amount of food, protein and carbohydrate ingested was similar for all conditions. Energy and fat intake were similar after the ingestion of the moderate soup compared with placebo.
However, the strong soup significantly lowered fat intake compared with placebo and ingestion of strong capsules also tended to suppress it, the team wrote in the February 2003 issue of the British Journal of Nutrition (pp 991-995).
Moreover, energy intake after strong soup and capsules tended to be lower than placebo.
The results indicate that the maximum tolerable dose is necessary to have a suppressive effect of red pepper on fat intake, said the researchers based at Japan's Fukuoka University, but they concluded that the main site of the action of red pepper is not in the mouth.
The findings support previous results showing that red pepper decreases appetite and subsequent protein and fat intakes in adults.
Another Japanese team reported two years ago that the essential oil of raspberries melts human fat more than three times as much as the compound capsaicin.
Only found in chilli peppers, capsaicin is an extremely powerful and stable alkaloid produced as a crystal by glands at the junction of the pepper's placenta and pod walls.
Researchers from the University of Zaragoza in Spain last year developed a method to extend the shelf life of burgers using peppers and tomatoes. Published in the February issue of the SCI's Journal of the Science of Food and Agriculture the findings are said to provide conclusive evidence that the shelf life of processed meats can be prolonged without further synthetic additives.
The team of researchers led by Pedro Roncales, produced eight batches of beef burgers containing different amounts of cayenne pepper, red sweet pepper and lycopene-enriched tomato products. They found that the addition of ground peppers (both sweet and hot) to the beef burgers delayed and 'significantly inhibited' the oxidation of both myoglobin and lipids as well as the growth of psychotropic bacteria.
The report indicates that the addition of lycopene rich tomato products was not as effective as the treatment with peppers, although they too exerted a significant antioxidative effect, so that the shelf life was extended to between 8 and 12 days.
According to Pedro Roncales, "peppers and tomatoes are already popular food additives in many parts of the world because they enhance the flavour of food. Now our results have shown that they may also be used as an effective alternative to synthetic antioxidants to prolong the shelf life of meat and meat products."