Effect of Domestic Processing and Cooking Methods on Total,HCl Extractable Iron and in vitro availability of Iron in Spinach and Amaranth Leaves

Abstract

Spinach (Spinacia oleracia) and amaranth (Amaranthus tricolor) leaves were stored in polyethylene bags and without packing for 24 and 48 hours in a refrigerator at 5°C and 30°C in polyethylene bags. The fresh leaves were also dried (oven and sun), blanched (5, 10 and 15 min) and cooked in an open pan and a pressure cooker. The processed leaves were analysed for total iron, its availability and antinutrient content. The iron content of these leaves varied from 26.54 to 34.14 mg/l00g, dry weight and its HCl-extractability and in vitro availability were 62.11–67.18% and 3.03–3.97% of total respectively. Drying and storage had no significant effect on total iron content, Hel-extractability and availability (in vitro), while blanching and cooking resulted in significant improvement of iron availability, and a significant reduction in oxalic acid content, while only blanching significantly reduced phytic acid and polyphenol contents. Thus cooking and blanching are good ways to improve HCl-extractability and in vitro availability of iron.

Get full access to this article

View all access options for this article.

References

Astier-Dumas

(1975). Changes in nitrate, vitamin C, magnesium and iron contents of spinach during cooking. Annales de la Nutrition et de l'Alimentation, 29, 239–244.

Bawa

S.F.

Yadav

S.P.

(1986). Protein and mineral contents of green leafy vegetables consumed by Sokoto population. J. Sci. Food Agric., 37, 504–506.

Chawla

Saxena

Seshadri

(1988). In vitro availability of iron in various green leafy vegetables. J. Sci. Food Agric. 46, 125–127.

Cisse

Guiro

A.T.

Diaham

Souane

Doumbouya

N.T.S.

Wade

(1998). Effect of home processing on iron availability of African pearl millet weaning foods. Intrn. J. Food Sci. Nutr., 49(50), 375–381.

Davies

N.T.

Reid

(1979). An evaluation of phytate, zinc, copper, iron and manganese content of soy bean and availability from soya based textured vegetables substitute of meat extrudes. Br. J. Nutr., 41, 579–589.

Daynelic

P.C.

van Dusseldorp

van Staveren

M.A.

Hautvast

J.G.A.G.

(1997). Effect of macrobiotic diets on linear growth in infants and children until 10 years of age. Eur. J. Clin. Nutr., 48 (Suppl), S103–S112.

Fawusi

M.O.A.

(1983). Nitrogen fertilization and storage temperature effects on the nutritive value of Solanum nigrum. J. Plant Foods, 5, 161–167.

Gopalan

Ramasastri

B.V.

Balasubramanian

S.C.

(1971). Nutritive Value of Indian Foods, NIN, ICMR, Hyderabad.

Gopalan

Ramasastri

B.V.

Balasubramanian

S.C.

(1995). Nutrient Composition of Indian Foods, NIN, ICMR, Hyderabad.

10.

Gupta

Barat

G.K.

Wagle

D.S.

Chawla

H.K.L.

(1989). Nutrient contents and antinutritional factors in conventional and nonconventional leafy vegetables. Food Chem., 31, 105–116.

11.

Harris

R.S.

Karmas

(1975). Nutritional Evaluation of Food Processing. AVI Publishing Co., Connecticut, 11, 205.

12.

Kamalanathan

Saraswathi

Devadas

R.P.

(1979). Calcium, iron, thiamin, ascorbic acid content of three vegetables cooked by three methods. Indian J. Nutr. Dietet., 9, 202–205.

13.

Kapanidis

A.N.

Lee

(1995). Heating cruciferous vegetables increase in vitro dialyzability of intrinsic and extrinsic iron. J. Food Sci., 60(1), 128–141.

14.

Lindsey

W.L.

Norwell

M.A.

(1969). A new DPTA-TEA soil test for zinc and iron. Agron. Abstr., 61, 84.

15.

Peterson

W.H.

Skinner

J.T.

Strong

F.M.

(1943). Elements of Food Biochemistry. Prince Hall Inc., New York.

16.

Rao

B.S.N.

Prabhavathi

(1978). An in vitro method for predicting the bioavailability of iron from foods. Am. J. Clin. Nutr., 31, 169–175.

17.

Reddy

M.B.

Love

(1999). The impact of food processing on the nutritional quality of vitamins and minerals. Adv. Exp. Med. Biol., 459, 99–105.

18.

Reddy

S.N.

Malewar

V.G.

(1992). Bio-availability of spinach (Spinacia oleracia) cultivated in soil fortified with graded level of iron. Plant Food Hum. Nutr., 42, 313–318.

19.

Singh

Jambunathan

(1981). Studies on desi and kabuli chickpea cultivars. The level of protease inhibitors, level of potyphenolic compounds and in vitro protein digestibility. J. Food Sci., 46, 1364.

20.

Snedecor

G.W.

Cochran

W.G.

(1967). Statistical Methods. Ames Iowa State University Press, Ames, Iowa, USA.

21.

Sood

D.R.

Chopra

A.K

(1973). Oxalate content of common grasses. Indian J. Animal Sci., 43, 476.

22.

Suarej

J.J.

Pozuelo

J.M.

(1972). Losses of minerals in vegetables. Annales de Bromatologia, 24, 361–456.

23.

Swain

Hills

W.E.

(1959). The phenolic constituents of Prumas domestical. The qualitative analysis of phenolic constituents. J. Sci. Food Agric., 10, 63.

24.

Valencia

Svanberg

Sandberg

A.S.

Ruales

(1999). Processing of quinoa (Chenopodium quino, wild): effect on in vitro iron availability and phytate hydrolysis. Intrn. J. Food Sci. Nutr., 50(3), 203–211.

25.

Zohm

Duden

Fricker

Heintze

Pauhus

Paulus

(1975). Influence of heat treatment of spinach at temperature up to 100°C on important constituents. V. Changes in mineral content (Na, K, Ca, Mg). Lebensmittel Wissenschajt Teehnologie, 8, 151–153.