The evaluations contained in this publication were prepared by the
    Joint FAO/WHO Expert Committee on Food Additives which met in Rome,
    4-13 June 19741

    World Health Organization     Geneva     1975


    1  Eighteenth Report of the Joint FAO/WHO Expert Committee on
    Food Additives, Wld Hlth Org. techn. Rep. Ser., 1974, No. 557.
    FAO Nutrition Meetings Report Series, 1974, No. 54.



         This substance has been evaluated for acceptable daily intake by
    the Joint FAO/WHO Expert Committee on Food Additives (see Annex 1,
    Refs Nos 19 and 34) in 1969 and 1973.

         Since the previous evaluation additional data have become
    available and are summarized and discussed in the following monograph.
    The previously published monographs have been expanded and are
    reproduced in their entirety below.



         These partially methoxylated polygalacturonic acids occur
    naturally and widely in fruits especially citrus fruits and apples and
    are part of the cell walls. They are therefore part of the normal
    diet. For the past 30 years some newer pectins have been in use, in
    which the de-esterified carboxyl groups have been partially amidated.

         At one time pectins have been used as plasma extenders as 1%
    solution but large intravenous doses have led to pectin deposition in
    the kidney, liver and lungs with consequential degenerative changes
    (Merck Index, 1968).

         Pectin has been shown to lower blood cholesterol in man (Keys et
    al., 1961) and in the rat (Wells & Ershoff, 1961). Four groups of
    three male and three female pigs were given diets for four weeks
    supplemented with either 5% pectin or 5% cellulose with or without
    dietary cholesterol. Pectin had no effect on body weight or plasma
    cholesterol level unless cholesterol was given in the diet. Pectin
    lowered significantly alimentary hypercholesterolaemia (Fisher et al.,
    1966; Fisher & Kannitz, 1964). Chicken fed cholesterol in the diet
    excrete more cholesterol if pectin is also added. Pectin has no effect
    on endogenous plasma cholesterol or may raise the level (Fisher et
    al., 1964). On the other hand swine fed pectin developed significantly
    higher blood cholesterol levels in other experiments (Fausch &
    Anderson, 1965).

         The digestibility of pectin was determined in groups of six rats
    fed 17.4% or 34.8% pectin in their diet for three weeks. At the lower
    dietary level there was no adverse effect on the utilization of other
    nutrients but at the higher level utilization of other nutrients was
    reduced. Pectin produced diarrhoea and growth was retarded at both
    dietary levels. Faecal recovery showed only 20% of orally ingested
    pectin to be digestible (Carey, 1958).

         Four normal dogs and two dogs with ileostomies were fed 140 g of
    pectin in a mixed diet over a seven-day period. An average of 90% of
    pectin was broken down. When fed during fasting periods an average of
    only 50% was broken down. In the case of studies with humans more
    pectin was broken down than in the dog study. A study involving two
    human patients with ileostomies showed that the breakdown of pectin
    occurred in the colon rather than in the upper intestine, and that
    bacterial enzymes were involved rather than enzymes of the animal
    organism (Werch & Ivy, 1941).

         Rats were fed diets containing 0.04 ppm Pb210 and either 5%
    pectin or 5% starch. The control group retained 15.8% of the
    radioactive lead and excreted 10.9% in the urine and 71.7% in the
    faeces. The pectin-fed animals retained an average of 24% less lead
    than controls, significantly less being excreted in the urine and more
    in the faeces (Murer & Crandall, 1942).


    Acute toxicity

         None available.

    Short-term studies


         Rats were fed 2.5-10% pectin without any deleterious effects - no
    details are available (Ershoff & McWilliams, 1945).

         In another experiment four groups of 10 male and 10 female rats
    were fed diets containing 0, 5%, 10% or 15% pectin (nonamidated) for
    90 days. No adverse effects were noted on general condition, behaviour
    and survival. Growth was slightly decreased at the 15% level, an
    observation previously noted in a range-finding test using 20% pectin.
    At 20% also reduced food consumption and food efficiency had been
    noted. Total serum protein and albumin were decreased at the 15%
    level but the haematological indices showed no treatment related
    differences. Blood chemistry showed no significant findings. The
    relative caecal weight was increased at the 15% level, a phenomenon
    also seen with modified starches and other high food intake of complex
    carbohydrates. Gross and histopathology were essentially normal (Til
    et al., 1972).

         In another experiment four groups of 10 male and 10 female rats
    were fed on diets containing 0, 5, 10 or 15% pectin (21% amidated) for
    90 days. No adverse effects were noted on general condition, behaviour
    and survival. Growth was slightly decreased at the 15% level and this
    finding was also noted in a range finding test using 20% pectin in the
    diet. Some decrease in growth occurred inconsistently also at the 10%

    dietary level. Food intake and food efficiency were not affected at
    any level. Haematological parameters showed no significant treatment
    related changes. Total serum protein and albumin were reduced at the
    15% level but the other clinical biochemical parameters and urinalysis
    were essentially normal. Caecal weights were increased at all levels
    but in a dose-related manner. These findings are reminiscent of what
    is seen when high amounts of starch, modified starch or certain other
    carbohydrates are fed. Gross and histopathology were normal but a
    slight degree of hyperkeratosis of the forestomach in some males was
    seen at the 10% and 15% level but is probably not of toxicological
    significance (Til et al., 1972).

    Long-term studies


         Groups of 20 male weanling Wistar rats were fed diets of Purina
    laboratory meal to which was added L.M. Pectin (approximately 18%
    amidated) or Pectin, N.F. at 10% of the diet. Control diets contained
    10% alphacellulose (Alphacel). The rats were fed for two years. The
    diets were made isocaloric by supplementing the alphacel with dextrose
    assuming a caloric equivalent for pectin of 0.6187 cal./mg.

         Mortality did not vary significantly between groups. Body weights
    for the pectin fed groups were similar but significantly less than
    that of the control animals. A comparison of grams of diet/kgm body
    weight showed a slightly greater food utilization for the pectin fed
    groups. The controls, however, consumed more food and gained more
    weight. There was no significant difference in average organ to body
    weight ratios for adrenal, heart, kidney, liver and spleen. The
    testes/body of the pectin fed groups did not differ from each other
    but both were significantly larger than those of the control group.

         Blood chemistry, SGOT and SPGT done at sacrifice showed no
    abnormalities in the pectin groups.

         Gross examination at necropsy showed no unusual findings. Two
    tumours were noted in the control group and one in the amidated pectin

         All gross lesions and adrenal, heart, kidney, liver, lung, spleen
    and testes will be examined histologically (Palmer, G. H. & Jones,
    T. R., 1974).

         Wistar rats of the Center for Investigation and Medical Research
    at Marseille strain were administered 100 mg/kg bw of, and 18.4%,
    amidated pectin, daily in the synthetic diet of Lacassagne MABI.
    Feeding was ad lib.

         Groups of 20 males and 20 females housed five to a cage were
    used. Controls consisted of a group of 450 rats fed the basic
    synthetic diet.

         Although the design of the experiment is not apparent the author
    mentions the littering of two generations. The author also stated
    there was no difference in growth and body weights of fed animals as
    compared to historical controls. Likewise electrophoretic examination
    of blood drawn just prior to sacrifice did not differ from controls. A
    complete histologic examination was carried out on 20 males and 20
    females after 24 months on experiment. Tissues of fed animals did not
    differ from those of the controls. The author states further that no
    adverse effects were noted on the ability of the animals to reproduce
    nor was the substance shown to be teratogenic (Mosinger, M., 1974).


         Nonamidated pectins and their salts as specified are normal
    constituents of the human diet and have also been administered
    intravenously at high levels to man without acute toxic effects. The
    available short-term tests show that even at 5% dietary levels no
    adverse effects are seen. The caecal enlargement without any
    accompanying histological changes is probably related to the presence
    of large amounts of a polysaccharide in the diet.

         Amidated pectins produced mild growth depression at a lower level
    (10%) than was seen with nonamidated pectins in a 90-day test as well
    as in a two-year study in rats. The available short-term study in rats
    revealed caecal enlargement but not associated with any histological
    abnormality. The available one-generation reproduction study and the
    two-year studies in rats lack histopathological and biochemical
    details. They cannot therefore be used for evaluation.


    Level causing no toxicological effect

         Rat: 5% (= 50 000 ppm) in the diet equivalent to 2500 mg/kg bw.

    Estimate of acceptable daily intake for man

         0-25 mg/kg bw.*


    *    Temporary.


         Required by June 1978.

         The results of histological examinations in the long-term
    studies. Adequate reproduction and embryotoxicity including teratology


    Carey, P. L. (1958) Thesis submitted to Purdue University

    Ershoff, B. H. & McWilliams, H. B. (1945) Amer. J. dig. Dis., 12, 21

    Fausch, H. D. & Anderson, T. A. (1965) J. Nutr., 85, 145

    Fisher, H. & Kannitz, H. (1964) Proc. Soc. Expl. Biol. Med., 116, 278

    Fisher, H. et al. (1964) Science, 146, 1063

    Fisher, H. et al. (1966) J. Atheroscler. Res., 6, 190

    Keys, A., Grande, F. & Anderson, J. T. (1961) Proc. Soc. Expl. Biol.
         Med. (N.Y.), 106, 555

    Merck Index (1968)

    Mosinger, M. (1974) Center for Investigation and Medical Research,

    Murer, H. K. & Crandall, L. A. jr (1942) J. Nutr., 23, 249

    Palmer, G. H. & Jones, T. R. (1974) Unpublished data Sunkist Growers

    Til, H. P., Seinen, W. and de Groot, A. P. (1972) CIVO Report No. 3843
         dated August 1972

    Wells, A. F. & Ershoff, B. J. (1961) J. Nutr., 86, 113

    Werch, S. C. & Ivy, A. C. (1941) J. Digest. Dis., 8, 101

    See Also:
       Toxicological Abbreviations
       Pectin (amidated) (WHO Food Additives Series 8)