4 Maataloustieteellinen A ikakauskirja Vol. 56: 49—59, 1984 Dietary fibre and available carbohydrates in Finnish vegetables and fruits PERTTI VARO, RAILI LAINE, KIRSTI VEIJALAINEN, AILA ESPO, ANNE WETTERHOFF and PEKKA KOIVISTOINEN Department of Food Chemistry and Technology, University of Helsinki, SF-00710 HELSINKI 71, Finland Abstract. The dietary fibre and available carbohydrate contents of vegetables, fruits and berries commonly consumed in Finland were analysed using the Englyst total carbohydrate method. The tables give the composition of 73 fresh and processed vegetables and fruits. The estimated average daily intakes of carbohydrates received from this category of foods were: total soluble sugars 23.7 g, starch 30.6 g and dietary fibre 7.2 g (energy level 10 MJ). Introduction Vegetables and fruits are the main sources of dietary fibre after cereal products. A con- siderable portion of vegetable and fruit fibre is water soluble. Consequently, its physical properties are different from those of cereal fibre; its waterbinding capacity is especially high (Eastwood 1983). Some fruit and berry products contain added sugar, but on the whole, natural sugars occur in greater amounts in this category of foods. The starch content is generally low, except in potato, which is one of the main sources of starch in Finland. In the present study the dietary fibre and available carbohydrates in the vegetable foods commonly consumed in Finland were analysed in an attempt to establish in detail the carbo- hydrate composition of Finnish foods (Varo et ai. 1984). The foods were analysed ac- cording to the method of Englyst (1981). Material and methods The sample material, 2—4 subsamples (1.5 —2 kg each) per item, was bought from local retail shops. Subsamples were washed and cut as in common household practice into edible portions, which were then united as one sample proper. Part of this was freeze- dried and homogenized in a blender. Only one sample per item was analysed. This is a Index words: food composition, dietary intake, sugars, starch, dietary fibre 49 JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=BfDphzXDFXKqqPX3.uqUt8lIxCT2TLJSOrA40pQ.endHQzQ4dWQFL7KSRY-s7CL0NYl9YgZgPYHIMhhAf6axRgEiIaHSt34xOs5yIavz-tfFbBsDjXL4XrD8whpRHoNCccq3D6wDV_WyCUh7EEAGFilvZ5Qw1eeEeQE9TSRgG2c0Ya8Xq0MnHGP-5huYcHlGG_MxVOG41p6GYcp0Z8MkJEIZjVohLQQ34SdjAyHioBbzyCFwRppEjYjRdfBrm7hAFLa_DYU9KfzkDfNjCQc2hkUNSsEueo2L2sjFumWGqBjrVXT3EBz8QNXlMQ 50 Table 1. Carbohydrate composition of fresh and processed vegetable foods. (W.s. = water soluble, W.i.s. = water insoluble, NCP = non-cellulosic polysaccharides) Content in 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 100 g of food Potato Carrot Beetroot Parsnip Celery Turnip Rutabaga Radish Horse- White (edible portion) root radish cabbage Water g 80 89 88 81 89 90 90 93 74 92 Available carbo- g 15.7 5.3 6.9 6.2 4.6 4.2 4.6 1.9 10.5 3.4 hydrates Free sugars g 0.8 5.1 6.8 3.2 3.6 3.9 3.9 1.6 6.6 3.4 fructose g 0.3 1.5 0.1 0.4 0.3 1.4 1.2 0.6 0.1 1.4 glucose g 0.3 1.8 0.2 0.9 0.5 2.0 2.4 1.0 0.6 1.9 sucrose g 0.2 1.8 6.5 1.9 2.8 0.5 0.3 tr 5.9 0.1 Starch g 14.9 0.2 0.1 3.0 1.0 0.3 0.7 0.3 3.9 0.0 Dietary fibre g 1.4 2.4 2.5 4.5 3.1 1.9 1.8 1.6 7.3 2.0 W.s. NCP g 0.4 0.8 1.3 1.7 1.1 0.7 0.6 0.6 1.0 0.9 W.i.s. NCP g 0.5 0.7 0.6 0.9 0.7 0.4 0.4 0.3 2.3 0.4 Cellulose g 0.4 0.8 0.5 1.8 1.1 0.7 0.7 0.6 2.9 0.6 Lignin g 0.1 0.1 0.1 0.1 0.2 0.1 0.1 0.1 1.1 0.1 Content in 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19 2.20 100 g of food Red Cauli- Broccoli Chinese Lettuce Spinach Nettle Onion Leek Chive (edible portion) cabbage flower cabbage Water g 92 92 89 95 95 93 82 87 91 91 Available carbo- g 3.5 2.2 1.9 2.2 0.8 0.4 1.3 4.8 2.4 1.7 hydrates Free sugars g 3.5 2.1 1.9 2.2 0.8 0.3 1.3 4.8 2.4 1.7 fructose g 1.2 0.9 0.7 0.9 0.4 0.1 0.5 1.5 1.0 0.9 glucose g 2.1 1.1 1.2 1.3 0.3 0.1 0.6 1.6 1.1 0.8 sucrose g 0.2 0.1 tr tr 0.1 0.1 0.2 1.7 0.3 tr Starch g 0.0 0.1 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 Dietary fibre g 1.9 1.9 2.5 1.2 1.2 1.3 4.1 1.2 2.1 2.1 W.s. NCP g 0.8 0.7 0.9 0.5 0.4 0.4 1.4 0.5 0.8 0.7 W.i.s. NCP g 0.3 0.4 0.6 0.2 0.2 0.4 0.8 0.2 0.5 0.4 Cellulose g 0.7 0.7 0.8 0.4 0.5 0.4 1.7 0.4 0.7 0.8 Lignin g 0.1 0.1 0.2 0.1 0.1 0.1 0.2 0.1 0.1 0.2 fructo- sane 4.0 51 Content in 2.21 2.22 2.23 2.24 2.25 2.26 2.27 2.28 2.29 2.30 100 g of food Dill Parsley Pea, Bean Tomato Sweet Cucumber Zucchini Rhubarb Apple (edible portion) fresh with pepper, pod red Water g 83 83 76 90 94 91 96 92 95 86 Available carbo- g 0.9 1.1 5.7 4.2 3.4 4.5 1.4 2.5 0.5 8.0 hydrates Free sugars g 0.8 0.8 4.0 2.4 3.3 4.5 1.4 2.5 0.5 7.9 fructose g 0.2 0.3 0.1 0.7 2.0 2.1 0.7 1.4 0.3 4.5 glucose g 0.3 0.5 0.2 1.1 1.3 2.3 0.7 1.1 0.2 2.1 sucrose g 0.3 tr 3.7 0.6 tr 0.1 tr tr 1.3 Starch g 0.1 0.3 1.7 1.8 0.1 0.0 0.0 0.0 0.0 0.1 Dietary fibre g 2.8 2.9 5.5 2.4 1.4 1.9 1.1 2.0 1.4 1.8 W.s. NCP g 1.1 0.8 0.5 0.9 0.6 0.9 0.4 0.6 0.7 0.7 W.i.s. NCP g 0.3 0.5 2.2 0.5 0.2 0.1 0.1 0.4 0.2 0.4 Cellulose g 1.1 1.3 2.7 0.9 0.4 0.7 0.5 0.9 0.4 0.6 Lignin g 0.3 0.3 0.1 0.1 0.2 0.2 0.1 0.1 0.1 0.1 52 Content in 2.31 2.32 2.33 2.34 2.35 2.36 2.37 2.38 2.39 2.40 100 g of food Pear Grape Orange Grape Mandarin Banana Plum Peach Bilberry Lingon- (edible portion) fruit berry Water g 84 82 87 89 87 74 84 87 87 85 Available carbo- g 8.0 15.0 8.9 6.5 8.3 18.3 8.4 7.8 6.4 6.8 hydrates Free sugars g 8.0 15.0 8.9 6.5 8.2 13.5 8.2 7.8 6.4 6.7 fructose g 4.8 7.3 2.7 2.6 1.4 2.7 1.3 1.3 2.9 2.9 glucose g 2.3 7.4 2.6 2.2 1.7 4.4 3.1 1.4 3.0 3.6 sucrose g 0.9 0.3 3.6 1.7 5.1 6.4 3.8 5.1 0.5 0.2 Starch g 0.0 0.0 0.0 0.0 0.1 4.8 0.2 0.0 0.0 0.1 Dietary fibre g 2.8 1.6 2.4 1.9 1.9 1.7 1.7 2.1 3.1 2.5 W.s. NCP g 0.7 0.7 1.2 1.0 0.9 0.7 0.7 0.8 0.5 0.4 W.i.s. NCP g 1.0 0.2 0.4 0.3 0.4 0.4 0.4 0.4 0.6 0.6 Cellulose g 0.7 0.5 0.6 0.5 0.5 0.4 0.4 0.6 0.7 0.6 Lignin g 0.4 0.2 0.2 0.1 0.1 0.2 0.2 0.3 1.3 0.9 53 54 Content in 2.41 2.42 2.43 2.44 2.45 2.46 2.47 2.48 2.49 2.50 100 g of food Cran- Rasp- Cloud- Straw- Black Red Goose- Rose Rowan Trivial (edible portion) berry berry berry berry currant currant berry hip berry milk-cup (Lactarius trivialis) Water g 87 86 84 89 82 84 88 60 74 90 Available carbo- g 3.4 4.1 7.7 7.4 7.8 7.5 5.4 9.6 6.2 1.2 hydrates Free sugars g 3.4 4.1 7.7 7.4 7.8 7.5 5.4 9.6 6.2 0.4 fructose g 1.2 2.2 3.7 2.4 4.0 4.4 2.4 5.2 2.5 tr glucose g 2.2 1.6 4.0 2.9 3.5 2.9 2.8 4.2 3.7 0.4 sucrose g tr 0.3 tr 2.1 0.3 0.2 0.2 0.2 tr— Starch g 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.8 Dietary fibre g 3.3 3.7 6.3 2.4 4.9 3.4 3.4 10.8 6.0 1.9 W.s. NCP g 0.5 0.4 0.5 0.9 1.9 1.1 1.1 3.5 0.9 0.1 W.i.s. NCP g 0.3 0.3 0.3 0.3 0.5 0.4 0.3 1.4 1.4 0.8 Cellulose g 0.6 0.8 0.6 0.5 0.7 0.6 0.9 3.3 1.2 1.0 Lignin g 1.9 2.2 4.9 0.7 1.8 1.3 1.1 2.6 2.5 0.0 55 Content in 2.51 2.52 2.53 2.54 2.55 2.56 2.57 2.58 2.59 2.60 100 g of food Cantha- Cep Gryromitra Potato Mashed Carrot, Pea, Mixed Pea, Champig- (edible portion) relle (Boletus (G. escu- starch, potato frozen frozen vegeta- canned non, (C. ciba- edulis) lenta) pearled powder bles, (with canned rius) frozen liquid) (drained) Water g 90 89 90 16 8 91 78 91 84 89 Available carbo- g 0.4 2.9 0.5 81.6 69.0 3.3 5.3 2.9 3.4 0.2 hydrates Free sugars g 0.4 2.0 0.3 0.9 5.7 3.2 4.0 1.9 2.1 0.0 fructose g tr 0.1 0.2 0.1 0.9 0.8 0.1 0.2 0.1 tr glucose g 0.4 1.2 0.1 0.5 1.1 0.7 0.1 0.1 0.1 tr sucrose g tr 0.7 0.2 0.7 1.7 3.8 1.6 1.9 Starch g 0.0 0.9 0.2 80.7 63.3 0.1 1.3 1.0 1.3 0.2 Dietary fibre g 2.3 1.3 1.4 1.4 6.9 2.5 6.5 2.2 4.4 2.4 W.s. NCP g 0.1 0.1 0.1 0.7 1.8 0.8 0.3 0.4 0.6 0.1 W.i.s. NCP g 1.1 0.6 0.3 0.5 2.8 0.6 1.7 0.5 0.5 1.6 Cellulose g 0.9 0.4 0.7 0.1 1.9 1.0 4.3 1.2 3.1 0.6 Lignin g 0.2 0.2 0.3 0.1 0.4 0.1 0.2 0.1 0.2 0.1 maltose lactose 0.1 3.0 Content in 2.61 2.62 2.63 2.64 2.65 2.66 2.67 2.68 2.69 2.70 100 g of food Cucumber, Beet- Sauer- Raisin Prune Date, Peach, Straw- Lingon- Apple (edible portion) pickled root kraut dried canned berry berry marma- in (with jam jam lade vinegar liquid) Water g 93 87 93 22 24 20 80 56 50 47 Available carbo- g 3.0 6.7 0.1 60.1 37.6 72.3 15.2 38.0 43.5 44.9 hydrates Free sugars g 3.0 6.7 0.1 60.1 37.6 72.3 15.2 37.5 43.5 44.9 fructose g 1.0 1.6 tr 28.9 14.6 23.0 3.2 7.2 14.0 12.3 glucose g 0.7 1.4 tr 29.7 14.4 28.9 4.2 6.6 15.3 10.6 sucrose g 1.3 3.7 0.1 1.5 8.6 20.4 7.8 23.7 14.2 22.0 Starch g 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 Dietary fibre g 1.8 1.8 1.7 9.7 7.7 6.0 0.8 1.3 1.5 0.9 W.s. NCP g 0.6 0.5 0.4 3.5 2.5 1.0 0.3 0.6 0.4 0.5 W.i.s. NCP g 0.5 0.4 0.4 1.7 1.4 1.2 0.2 0.2 0.3 0.2 Cellulose g 0.6 0.8 0.8 2.3 2.8 1.3 0.2 0.4 0.4 0.2 Lignin g 0.1 0.1 0.1 2.2 2.0 2.5 0.1 0.1 0.4 0.0 56 57 reflection of the complexity of the analytical procedure, which allowed only a very limited number of samples to be analysed within the context of the present study. The analytical scheme used was that de- veloped by Englyst(l9Bl) and slightly mod- ified by Laine et ai. (1981). The method has been described in detail in the preceding pa- per (VARoet al. 1984). The standard sample was the same as in the cereal study. For com- parison, the total dietary fibre of some vege- tables and fruits was also analysed with the enzymatic-gravimetric method of Asp et al. (1983). This showed that the results obtained with the present method were 10—15 % lower than those obtained with the enzymatic- gravimetric analysis in this category of foods (Varo 1984). The results of the water-soluble non-cel- lulosic polysaccharide (w.s. NCP) fraction tended to be the most variable, and the whole fraction was therefore completely re-analysed on a sample 10 times bigger using gravimetric determination of filtered and dried precipitate. Free sugars and, less often, lignin caused re- checks. Content in 2.71 2.72 2.73 100 g of food Marma- Tomato Mustard, (edible portion) lade ketchup prepared Water g 45 70 66 Available carbo- g 46.6 19.2 14.1 hydrates Free sugars g 46.6 19.2 14.1 fructose g 14.7 3.8 3.0 glucose g 12.9 4.3 3.5 sucrose g 19.0 11.1 7.6 Starch g 0.0 0.0 0.0 Dietary fibre g 0.9 1.2 1.7 W.s. NCP g 0.6 0.4 0.6 W.i.s. NCP g 0.1 0.2 0.6 Cellulose g 0.1 0.5 0.3 Lignin g 0.1 0.1 0.2 Table 2. Sugar and uronic acid composition of w.s. NCP and w.i.s. NCP in some vegetables and fruits. w.s. NCP w.i.s. NCP % of total g/100 g % of total g/100 g rha man glu gal ara xyl uro total» rha man glu gal ara xyl uro total» Potato 2 3 4 26 6 4 57 2.0 3 3 33 32 9 7 14 2.5 Carrot 2 1 2 13 12 2 69 7.3 3 2 5 28 19 3 42 6.4 Beetroot 2 1 4 6 12 2 74 10.8 2 2 4 11 39 5 38 5.0 Cabbage 2 1 2 7 9 2 77 11.3 3 2 4 13 15 8 56 5.1 Lettuce 3 3 4 18 10 5 57 8.0 5 2 3 12 6 8 63 4.0 Tomato 1 2 4 12 9 6 66 10.2 2 10 17 22 17 21 12 3.3 Apple tr tr 1 5 14 2 79 5.0 114 19 28 15 31 2.9 Strawberry 3 2 5 9 12 5 65 8.2 6 4 9 16 16 35 15 2.7 Black currant 4 3 6 9 13 6 59 10.6 3 17 15 19 16 18 12 2.8 " In dry product Abbreviations: rha = rhamnose, man = mannose,glu = glucose, gal = galactose, ara = arabinose, xyl = xylose, uro = uronic acids, tr = traces w.s. = water soluble, w.i.s. = water insoluble, NCP = non-cellulosic polysaccharides Results and discussion The results of the present study are given in Table 1. Free sugars, starch and the main components of dietary fibre are tabulated. By and large, the results are consistent with findings from earlier carbohydrate studies (Salo 1967, Paul & Southgate 1979, Eng- lyst 1981, Souci et al. 1981). Sugars. Most vegetables, fruits and berries contain considerable amounts of natural sug- ars. Usually the three sugars glucose, fruc- tose and sucrose are present, fructose often being the most abundant. Sorbitol may be present, too (Souci et al. 1981), but it was not measured in the present study. Canned fruits, jams and marmalades contain appre- ciable added sugar. Starch. The amount of starch, if present, is usually quite low. Its concentration is dis- tinctly highest in potato and banana. Some vegetables contain fructosanes (Salo 1967). In this study they were detected in onion. In the present analytical scheme these carbo- hydrates were cohydrolysed with starch. Dietary fibre. The fibre content of vege- tables and fruits is high in relation to their energy content. It was highest in some berries with seeds, which increase the lignin fraction in particular. The water-soluble fraction was usually quite large. The sugar and uronic acid composition of w.s. NCP and w.i.s. NCP of some vegetables and fruits is given in Table 2. Uronic acids were the main con- stituents of the w.s. NCP fraction; the com- position of w.i.s. NCP was more variable and included large amounts of galactose, pentoses and uronic acids. According to statistics (Anon. 1981, Agric. Econ. Res. Inst. 1983), the average consump- tion of vegetables in 1981 was 116 g/d and that of fruits 239 g/d. The average consump- tion of potato was 162 g/d. The vegetables with the highest consumption are cucumber, tomato, cabbage and carrots, their share being over 60 % of the total. Citrus fruits, apples and banana are the principal fruits, their share being nearly 70 % of total fruit consumption. The most common processed products are various juices, especially orange juice. The estimate of the daily intakes of sugars and fibre given in Table 3 is based on these statistics. The estimated fibre intake from cereals was 11.6g/d (VARoet al. 1984). Thus, the total fibre intake is 19 g/d. This is well within the range of other estimates of the average fibre intake in Finland (Laakko- nen & Haaramo 1983). It was also calculated that added sugar accounts for about 20 °/o of the total intake of soluble sugars received from this category of foods. Acknowledgement. This study was supported by the Academy of Finland and the Finnish Sugar Company Ltd. Table 3. The estimated average intake (g/d) of dietary fibre and available carbohydrates derived from vegetables and fruits (energy level 10 MJ). Vegetables Fruits Potato Total Total sugars 3.3 19.3 1.1 23.7 fructose 1.2 7.3 0.4 8.9 glucose 1.2 5.9 0.4 7.5 sucrose 0.9 6.1 0.3 7.3 Starch 0.2 0.6 29.8 30.6 Dietary fibre 1.8 3.3 2.1 7.2 w.s. NCP 0.6 1.3 0.6 2.5 w.i.s. NCP 0.3 0.6 0.7 1.6 cellulose 0.7 0.8 0.6 2.1 lignin 0.2 0.6 0.2 1.0 58 References Agricultural Economics Research Institute, 1983. Food balance sheet 1981. Helsinki. Anon 1981. Vihannesten kulutus. Puutarhauutiset No. 47, 1112. Asp, N.-G., Johansson, C.-G., Hallmer, H. & Siueström, M. 1983. Rapid enzymatic assay of insoluble and soluble dietary fiber. J. Agric. Food Chem. 31: 476 —482. Eastwood, M.A. 1983. Physical properties of fibre towards bile acids, water and minerals. In: Dietary Fibre (Eds. G.G. Birch & K.J. Parker), p. 149—164. Applied Science Publishers, London. Enclyst, H. 1981. Determination of carbohydrate and its composition in plant materials. In: The Analysis of Dietary Fiber in Food (Eds. W.P.T. James & O. Theander), p. 71—93. Marcel Dekker, N.Y. Laakkonen, E. & Haaramo, A.-M. 1983. Ravintokuidun saannin kehitys 1900-luvulla,Elintarvikkeiden Tutki- mussäätiö, Julkaisu No. 13: 86—103. Laine, R., Varo. P. & Koivistoinen, P. 1981. Observa- tions on the analysis ofdietary fiber. In: The Analysis of Dietary Fiber in Food (Eds. W.P.T. James& O. Theander), p. 21—27. Marcel Dekker, N.Y. Paul, A.A. & Southgate, D.A.T. 1979. McCance and Widdowson’s the Composition of Foods, 4th ed. FIMSO, London. Salo, M.-L. 1967. Carbohydrates of some vegetables. Acta Agric. Fenn. 109, 1: 101—104. Souci, S.W., Fachmann. W. & Kraut, H. 1981. Food Composition and Nutrition Tables 1981/82. Wis- senschaftliche Verlagsgesellschaft, Stuttgart. Varo, P. 1984. Suomalaisten elintarvikkeiden ravinto- kuitututkimus. Elintarvikeylioppilas No. 2: 24—27. Varo, P., Laine, R., Veijalainen, K., Pero, K. & Koivis- toinen, P. 1984. Dietary fiber and available carbo- hydrates in Finnish cereal products. J. Scient. Agric. Soc. Finl. Ms received January 30, 1984 SELOSTUS Suomalaisten elintarvikkeiden hiilihydraatti- tutkimus kasvisten, hedelmien ja marjojen ravintokuitu-, tärkkelys- ja sokeripitoisuudet Pertti Varo, Raili Laine, Kirsti Veijalainen, Aila Espo, Anne Wetterhoff ja Pekka Koivistoinen Elintarvikekemian ja -teknologian taitos, Helsingin yliopisto, 00710 Helsinki Tässä tutkimuksessa määritettiin meillä kulutuksen kannalta tärkeimpien kasvisten, hedelmien ja marjojen sekä niistä saatavien valmisteiden hiilihydraattikoostu- mus. Analyyttisenä menetelmänä käytettiin ns. Englys- tin kokonaishiilihydraattimenetelmää. Julkaisussa on taulukoitu tiedot 73 elintarvikenimikkeen hyväksikäy- tettävien hiilihydraattien ja ravintokuidun määrästä ja laadusta. Tutkimus on osa poikkileikkaustutkimusta. jonka tavoitteena on saada yleiskuva suomalaisten elin- tarvikkeiden hiilihydraattikoostumuksesta. Saatujen tu- losten ja kulutustietojen perusteella arvioitiin hiilihyd- raattien keskimääräinen päiväsaanti kasvisryhmän elin- tarvikkeista. Saantiarvot olivat: liukoisia sokereita yh- teensä 23.7 g, tärkkelystä 30.6 g ja ravintokuitua 7.2 g (energiataso 10 MJ). 59