Asna Urooj

Effect of processing on nutritionally important starch fractions in rice varieties

In the present study the effect of processing on starch fractions (rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch) were measured, using controlled enzymic hydrolysis with pancreatin and amyloglucidase, in six rice varieties; namely, BT rice, Gauri rice, Sona masoori, parboiled rice, Salem parboiled rice, and steamed rice. The processes studied were pressure cooking, boiling, steaming and straining. Rapidly available glucose (RAG) was also measured to derive a Starch Digestion Index (SDI). Cooking of rice by different methods decreased the amylose content. The degree of gelatinization ranged from 56 to 95, with pressure cooking resulting in the maximum degree. The starch fractions varied depending on the cooking method. Significant inverse correlations were seen between RDS and SDS (r = 0.40, P < 0.05), and between amylose and SDI (r = 0.60, P < 0.01). RAG and RDS related positively (r = 0.90, P < 0.01). The SDI of rice varieties cooked by the boiling and straining method were significantly higher (P < 0.05). The results emphasize that cooking methods influence the nutritionally important starch fractions in rice varieties.

In vitro studies on the hypoglycemic potential of Ficus racemosa stem bark.

BACKGROUND Medicinal plants have been reported to play an important role in modulating glycemic responses and have preventive and therapeutic implications. Several mechanisms have been proposed for the antidiabetic effect of medicinal plants such as inhibition of carbohydrate-metabolizing enzymes, manipulation of glucose transporters, beta-cell regeneration and enhancing insulin-releasing activity. The present investigation evaluated the possible mechanism of action through which Ficus racemosa stem bark (Moraceae) exerts its hypoglycemic effect using suitable in vitro techniques. RESULTS Ficus racemosa bark (FRB) exhibited significantly higher (P < or = 0.01) glucose-binding capacity than wheat bran (WB) and acarbose (ACB) consequently showed significantly higher (P < or = 0.01) retardation of glucose diffusion compared to WB and ACB. In case of amylolysis kinetics the liberation of glucose was greatly inhibited by FRB, as reflected by a significantly lower (P < or = 0.01) glucose diffusion rate in the system containing FRB compared to the control and acarbose. Furthermore, FRB significantly increased (P < or = 0.01) the rate of glucose transport across the yeast cell membrane and also in isolated rat hemi-diaphragm. CONCLUSION The findings indicate F. racemosa bark to possess strong hypoglycemic effect and hence can be utilized as an adjunct in the management of diabetes mellitus.

Physico-chemical characteristics of defatted rice bran and its utilization in a bakery product

Defatted rice bran (DRB), a byproduct of rice milling is a rich source of dietary fiber and minerals. In the present study, the physico-chemical characteristics, antioxidant potential of defatted rice bran (Laboratory-LDRB and Commercial -CDRB) and its utilization in preparation of bread were studied. The effect of incorporation of CDRB at varying levels (5, 10 & 15%) on the quality characteristics of bread including physical, rheological and sensory attributes were evaluated and the dietary fiber content and antioxidant activity were determined. The results indicated that LDRB had better nutrient profile, physical and antioxidant properties than CDRB. On the basis of physical characteristics, breads with 5% and 10% CDRB were found to be acceptable as such and those containing 15% were acceptable with addition of bread improvers. The dietary fiber content and total antioxidative activity of bread increased with increasing levels of CDRB, which also improved the shelf life. The results reveal that DRB can be incorporated in breads upto 10% and 15% as such or with bread improvers respectively, as source of fiber and natural antioxidant, as a functional ingredient.

Antioxidant efficacy of mulberry (Morus indica L.) leaves extract and powder in edible oil.

The antioxidant activity of mulberry (Morus Indica L.) leaves was evaluated in rice bran oil (RBO). The oil was subjected to accelerated oxidation at 100° C for 5 days and heat treatment at 180°C for 1 h. In order to examine its potential antioxidant activity, the oxidative stability of the oils was evaluated by employing peroxide value (PV), radical scavenging activity (RSA), thiobarbituric acid reactive substances assay (TBARS), and percent free fatty acids (FFA). Mulberry in two forms viz: the methanolic extract and powder were applied to RBO at 200 ppm and 0.05%, respectively, and results were compared with RBO treated with a synthetic antioxidant-BHT. The PV, RSA, TBARS, and FFA values indicated that both mulberry extract and powder were effective in inhibiting lipid oxidation when compared to synthetic antioxidant BHT. Thus, mulberry leaves may serve as a new source of natural antioxidant for use in food systems.

Glucose-lowering, Hepatoprotective and Hypolipidemic Activities of Stem Bark of Ficus racemosa in Streptozotocin-Induced Diabetic Rats

The present study evaluated the antihyperglycemic, hepatoprotective, and hypolipidemic effects of F. racemosa bark powder and aqueous extract in streptozotocin-induced diabetic rats. Streptozotocin-induced diabetic rats (n = 6) were treated with F. racemosa Linn (Moraceae) bark powder (FRP) and aqueous extract (FRAE) for six weeks. Blood glucose was determined every 15 days using a portable glucometer. At the end of the study period, the rats were sacriÞ ced and levels of serum glucose, protein, total cholesterol, triglycerides, AST, ALT, TBARS, and glutathione were determined as indicators of antihyperglycemic, hypolipidemic, and hepatoprotective activities, as well as of antioxidant potential. TBARS and glutathione levels were determined in the liver and the kidneys also. Both the bark powder and aqueous extract of F. racemosa bark caused a signiÞ cant reduction (P ≤ 0.05) in blood glucose (54 and 66% respectively). A signiÞ cant reduction (P ≤ 0.05) was also observed in serum cholesterol and triglyceride levels to the control levels. The aqueous extract was more effective and caused a signiÞ cant reduction (P ≤ 0.05) in TBARS, AST, ALT levels compared to untreated diabetic rats. However, it did not reach control levels. A signiÞ cant increase in glutathione concentrations over the control levels was also observed in rats treated with F. racemosa bark. It is concluded that F. racemosa bark has a signiÞ cant hypolipidemic and hepatoprotective effect besides being a potent antihyperglycemic agent. Key words: Antihyperglycemic, antioxidant effect, Ficus racemosa, hypolipidemic, hepatoprotective.

Effect of Incorporation of Mint on Texture, Colour and Sensory Parameters of Biscuits

In recent years, there has been a general trend towards replacing the use of synthetic antioxidant by natural antioxidant, derived from various plants, spices and oil seeds, in processed food. The present study deals in the use of mint (Mentha spicta L) as a source of natural antioxidant in different forms viz, powder, extract, and pure menthol for its application in biscuits. Formulation of mint component was designed based on preliminary studies using various parameters such as instrumental assessment for texture and color measurement and sensory evaluation. The selected levels were as follows 1% mint powder (MNT-P), 500 mg mint extract (MNT-E), and 100 ppm pure menthol (MNT-M) for incorporation in biscuits. The biscuits with different mint forms were packed in unit pouches of metallized polyester/poly laminate and stored at room temperature for five months. The texture value of biscuits with mint powder (MNT-P) received higher scores, comparable with the control (CNT) and BHA (BNT) biscuit indicating their crisp nature. However, color measurement (ΔE) values in MNT-P biscuits were higher followed by MNT-E biscuit due to their green color, whereas the values of MNT-M biscuit were comparable with the CNT and BHA biscuit indicating MNT-M did not impart any change in the color of the biscuit. The sensory scores of MNT-M were higher (P ≤ 0.05) than MNT‐P and MNT-E biscuits. MNT-P variation received significantly higher (P ≤ 0.05) scores in terms of texture, taste and mouth feel. The results indicate that MNT-P biscuits were highly acceptable compared to MNT-E and MNT-M biscuits.

Effect of barley incorporation in bread on its quality and glycemic responses in diabetics

Barley has emerged as a new source of dietary fibre with promising evidence of health benefits, viz. both hypoglycemic and cholesterolemic effects in vivo. In the present study, incorporation of both pearled and whole barley at varying levels (5 to 25%) on the quality characteristics of bread-including physical, rheological and sensory attributes were determined. Further, glycemic responses to, as well as satiety scores of barley containing breads were evaluated in diabetic (NIDDM) subjects. On the basis of key attributes, (viz. loaf volume, texture, taste and flavour), breads having 10% whole barley (WB) flour, or 15% pearled barley (PB) flour were found to be acceptable. Both WB and PB bread resulted in significantly lower postprandial blood glucose than standard white bread. Two hours after the test meal, both the experimental breads showed a higher satiety score than did the white bread. The results reveal that by incorporation of barley at suitable levels, it is possible to formulate breads that woul...

Glycaemic responses to cereal-based Indian food preparations in patients with non-insulin-dependent diabetes mellitus and normal subjects

The in vivo glycaemic responses to six cereal-based foods traditionally consumed in South India were evaluated in patients with non-insulin-dependent diabetes mellitus (NIDDM) and healthy volunteers. All foods contained 50 g carbohydrate and were compared with a 50 g glucose load. Also studied were the in vitro starch digestibility and nutrient composition of the foods. The postprandial responses to the foods at 30, 60 and 120 min were significantly (P < 0.05) lower than those to the reference glucose, in both groups. The peak glucose responses for three foods, i.e. chapatti, idli and poori, occurred 60 min postprandially in both groups. The glycaemic index (GI) values ranged from 67 to 90 in NIDDM and from 44 to 69 in healthy subjects with no significant differences within the groups. Significant relationships were observed between peak responses and area under the curve for foods in patients with NIDDM and in vitro rate of starch hydrolysis (r 0.83, r 0.85, P < 0.05). The GI values predicted using in vitro data were found to be similar to the GI values observed in patients with NIDDM. The GI concept is useful for identifying foods in the habitual Indian diet with attributes of the desired glycaemic effect such as delayed peak rise and low area under the curve.

Radical scavenging and angiotensin converting enzyme inhibitory activities of standardized extracts of Ficus racemosa stem bark.

The present study evaluated the radical scavenging and angiotensin converting enzyme (ACE) inhibitory activity of cold and hot aqueous extracts of Ficus racemosa (Moraceae) stem bark. The extracts were standardized using HPLC. Radical scavenging activity was determined using 1,1‐diphenyl‐2‐picrylhydrazyl radical and angiotensin converting enzyme inhibitory activity using rabbit lung and partially purified porcine kidney ACE. HPLC profiles of cold aqueous extract (FRC) showed the presence of bergenin, an isocoumarin, while hot aqueous extract (FRH) was found to contain ferulic acid, kaempferol and coumarin in addition to bergenin. FRH showed significantly higher (p ≤ 0.01) radical scavenging activity than FRC and butylated hydroxytoluene (BHT), consequently resulting in a significantly lower (p ≤ 0.01) IC50 value than FRC and BHT. Both the extracts exhibited a dose dependent inhibition of porcine kidney and rabbit lung ACE. FRH showed significantly higher (p ≤ 0.01) activity than FRC with lower IC50 values of 1.36 and 1.91 μg/mL respectively, for porcine kidney and rabbit lung ACE, compared with those of FRC (128 and 291 μg/mL). Further, a significant correlation (r = 0.893; p ≤ 0.05) was observed between radical scavenging activity and ACE‐inhibitory activity. This is the first report on the ACE‐inhibitory activity of F. racemosa stem bark suggesting its potential to be utilized as a therapeutic alternative for hypertension. Copyright

Application of Phenolic Extracts from Selected Plants in Fruit Juice

Plant phenolics have gained considerable interest in recent years for their potential effects against food related microorganisms. In the present study, phenolic extracts from the leaves of three plants namely Moringa oleifera, Morus indica, and Mentha spicata were prepared by a mixture of methanol/acetone/water. The UV spectra of extracts were recorded and contents of total phenolics determined. The extracts were incorporated in pineapple juice and their solubility and stability were studied. In addition, the acceptability of treated juice samples was sensory evaluated. The solubility of M. indica and M. oleifera extracts was found to be more than that of M. spicata. The two extracts were also stable in the pH environment of pineapple juice when stored at 4°C for two weeks. The pineapple juice treated with M. indica extract was more acceptable compared to that of M. oleifera, according to sensory evaluation. Therefore, the effect of addition of phenolic extract from M. indica on the shelf life of pineapple juice stored at 4°C was investigated by monitoring the changes in titrable acidity and sensory parameters for 8 weeks. Results indicated that the extracts of natural phenolic compounds can be used to improve the quality and safety of foods.