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2015 - 20194
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Subject: Food and Nutrition × End date: 2019 × Start date: 2014 × Type: Thesis ×
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    ThesisItemOpen Access
    EFFECT OF PROCESSING ON IN-VITRO STARCH DIGESTIBILITY AND GLYCEMIC INDEX OF SELECTED RICE VARIETIES OF ASSAM
    (AAU, Jorhat, 2019-07) Devi, Laishram Maria; Das, Pranati
    Rice is one of the most widely consumed staple foods, especially in Asia. It accounts for 20 per cent of the world’s dietary energy supply. As a major component of rice, starch plays an important role in human nutrition, and consequently its characterisation in rice variants is of high nutritional importance. To this, the present study estimated the in-vitro starch digestibility (resistant starch (RS), non-resistant starch (NRS) and total starch (TS)), available starch (AS), hydrolysis index (HI) and in-vitro glycemic index (GI) of different processing techniques. Ten red kernel rice varieties of Assam were analyzed for the effect of both raw rice flour and freshly cooked rice in dehusked rice and 6 per cent degree of polishing. Dehusked and polished rice yield were 68.33±0.38 to 75.23±0.19 per cent and 64.14±0.13 to 73.67±0.29 per cent, respectively. Head rice yield (HRY) and broken rice yield (BRY) of the dehusked rice varieties were 54.03±0.34 to 74.34±0.05 per cent and 0.68±0.06 to 14.55±0.32 per cent, respectively. Polishing of rice grains decreased HRY (41.76±0.40 to 68.39±0.09%) but increased BRY (2.05± 0.11 to 22.52±0.41%). The dehusked samples had 17.64±0.11 to 19.17±0.04 g/100 g of RS, 61.19±0.07 to 66.28±0.19 g/100g of NRS and 80.01±0.11 to 85.02±0.20 g/100g of TS. Resistant starch decreased significantly (p≤0.05) on polishing as well as cooking, while NRS and TS increased significantly (p≤0.05) in polishing. However, TS decreased on cooking. Available starch, hydrolysis index and glycemic index of the dehusked rice samples were in the range of 51.80±0.14 to 89.57±0.51 per cent, 3.37±0.02 to 14.67±0.03 per cent and 41.91±0.03 to 50.99±0.11 per cent, respectively. Polishing of the rice samples showed no significant (p≥0.05) change in AS, HI and GI. Cooking significantly reduced AS, whereas HI and GI content increased significantly (p≤0.05) upon cooking. Therefore, polishing and cooking of rice grains had significant effect on the in-vitro starch digestibility and GI. In addition, varieties of Jul and Kaoi Jamfri had comparatively higher RS and lower GI, and thus can be recommended for popularization. Also, further research can be extended for analyzing the effect of degree of polishing and different cooking methods on starch digestibility and GI. Such nutritionally distinguished rice varieties could be used to develop rice based products and supplementary food mixes which have therapeutic values.
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    ThesisItemOpen Access
    EFFECT OF PROCESSING ON NUTRIENT COMPOSITION AND BIOACTIVE COMPONENTS OF SELECTED RICE VARIETIES OF ASSAM
    (AAU, Jorhat, 2019-07) Gogoi, Senorita; Das, Pranati
    A study was carried out with the objective to determine the effect of processing on physico- chemical properties and bioactive compounds of selected red rice varieties of Assam. Seven red pigmented rice varieties were selected and procured from Krishi Vigyan Kendra, Silapathar, Dhemaji. A series of laboratory tests were performed on both the uncooked and cooked forms of dehusked and 6 per cent polished rice samples to find out the physico- chemical properties, mineral content and the bio- active compounds. The dehusked and polished rice yield of the selected red rice varieties was found to be in the range of 68.33±0.52 to 75.23±0.47 per cent and 64.14±0.39 to 73.67±0.69 per cent, respectively. Head rice yield (HRY) and broken rice yield (BRY) of the varieties ranged from 55.13±0.99 to 73.93±0.73 per cent and 0.93±0.16 to 13.60±0.58 per cent, respectively and polishing of the rice grains decreased HRY (40.82±1.12 to 67.44±1.23 per cent) but increased the BRY (2.96± 0.19 to 23.15±1.06 per cent). Length, breadth, thickness and length/breadth ratio of the dehusked rice samples ranged from 5.00±0.33 to 5.90±0.32 mm, 2.10±0.21 to 2.75±0.35 mm, 1.59±0.14 to 2.03±0.02 mm and 1.89±0.40 to 2.85±0.36, respectively. Thousand grain weight, volume and bulk density ranged from 13.46±0.00 to 19.40±0.00 g, 16.67±0.29 to 25.83±0.29 ml and 0.69±0.01 to 0.88±0.01 g/ml in the dehusked samples. The length, breadth, thickness, thousand grain weight and thousand grain volume of rice varieties significantly (p≤0.05) reduced on polishing, whereas the length/ breadth ratio and bulk density increased. Water absorption capacity (WAC), cooking time and grain elongation ratio of the dehusked rice samples ranged from 2.06±0.16 to 2.77±0.21 ml/g, 21.66±1.53 min. to 38.33±1.15 min. and 0.98±0.01 to 1.14±0.02. Water absorption capacity and grain elongation ratio significantly (p≤0.05) increased whereas the CT decreased significantly (p≤0.05) on polishing. The dehusked samples had 11.64±0.08 to 12.75± 0.04 g/100 g of moisture, 9.31±0.00 to 13.50± 0.66 g/100 g of crude protein, 2.53± 0.09 to 3.71±0.04 g/100 g of crude fat, 0.56±0.01 to 0.81±0.03 g/100 g of crude fibre, 1.24±0.01 to 2.60±0.03 g/100 g of total ash, 68.60±1.44 to 73.87±0.18 g/100 g of carbohydrate and 352.99±0.80 to 361.86±2.78 kcal/100 g of energy. The crude protein, crude fat, crude fibre and total ash content decreased significantly (p≤0.05) on polishing as well as cooking. The carbohydrate content significantly (p≤0.05) increased on polishing as well as cooking. The dehusked samples had iron, zinc, calcium, phosphorus and magnesium content in the range of 4.47±0.18 to 12.46±0.63 mg/100g, 1.41±0.11 to 2.93±0.05 mg/100 g, 9.96±0.11 to 37.73±0.58 mg/100g, 134.54±3.44 to 221.57±3.48 mg/100 g and 0.13±0.01 to 1.21±0.00 mg/100 g, respectively. Polishing significantly (p≤0.05) reduced the iron, zinc, calcium, phosphorus and magnesium content. Cooking of the rice samples showed no significant (p≥0.05) change in the iron, zinc, calcium content on cooking, while magnesium content reduced significantly (p≤0.05). No significant (p≥0.05) change in phosphorus content was seen in the dehusked samples, whereas the polished samples showed significant (p≤0.05) loss of phosphorus upon cooking. The bioactive compounds were determined in terms of total antioxidant capacity (TOA), total anthocyanin content (TAC), total phenolic content (TPC), total flavonoid content (TFC) and total carotenoid content (TCC) and were observed to significantly (p≤0.05) decreased on polishing as well as cooking. The TOA, TAC, TPC, TFC and TCC of the dehusked samples ranged from of 44.67±0.45 to 81.08±0.45 per cent, 11.35±0.45 to 23.71±0.94 mg/100 g, 46.13±0.88 to 109.50±0.64 mg GAE/100 g, 12.24±1.19 to 39.23±1.59 mg QE/100 g and 0.42±0.02 to 1.85±0.07 μg/100 g, respectively. The present study provides the evidence that polishing and cooking of the rice grains has significant effect on the physical and nutrient quality of the rice varieties. The variety Kaoi Jamfri showed better mineral content and antioxidant capacity than rest of the varieties and can be recommended for popularization among rural and urban population. Further studies may be taken out to find out the degree of polishing at which maximum milling recovery and retention of nutrient takes place. The rice varieties may be used to formulate supplementary food mixes, develop rice based products. The unpolished rice varieties may be recommended for consumption to prevent nutrient deficiencies among the people. Further studies can be taken out to study the use of the rice bran to formulate functional food.
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    ThesisItemOpen Access
    PHYSICO-BIOCHEMICAL CHARACTERISATION AND VALUE ADDITION TO SELECTED MINOR FRUITS OF ASSAM
    (AAU, Jorhat, 2016-07) Firdusi, Syeda Nishat; Bhattacharyya, Ruma
    The present investigation entitled “Physico-Biochemical Characterisation and Value Addition to selected Minor Fruits of Assam” was carried out in order to study the physico-chemical properties of the selected minor fruits namely Rhus semialata (Local name- Nagatenga), Baccaurea sapida (Local name- Leteku), Flacourtia gangomos (Local name - Poniol) and Garcinia cowa (Local name – Kujithekera) and products were developed from these selected fruits. The qualities of the developed products were also evaluated. The entire study was sectioned in four well defined separate parts i.e. 1) Evaluation of the physico-chemical composition of the selected minor fruits. 2) Development of products from the selected fruits and their quality evaluation, 3) Quality evaluation of the developed products across storage, 4) Microbial load of the developed products was studied to determine the shelf life of the products. The physical parameter of the minor fruits was studied and found that all the fruits possess good amount of edible portion except Leteku. The shelf-life of Nagatenga (Rhus semialata), Leteku (Baccaurea sapida), Poniol (Flacourtia gangomas) and Kujithekera (Garcinia cowa ) was recorded as 1.83±0.28, 6.00±1.00, 4.00±1.00 and 2.33±0.57 days respectively under ambient temperature. The shelf life of fruits can be extended by processing it to different food products like jam, jelly and squash. In case of value addition to Leteku (Baccaurea sapida) only those products should be considered which required juice of fruits such as beverages as the pulp content (26.16±1.25 g/100g) of the fruit is very low with high juice content (40.00±2.64 ml/100g). The acid content of Nagatenga (Rhus semialata) (3.46±0.25%) and Kujithekera (Garcinia cowa) (4.87±0.19%) are high with good amount of pulp content and so can be consider for pickle, chutney and sauce making. The juice content of Poniol (Flacourtia gangomas) was found to be low (20.33±4.04 ml/100g) but the TSS content of the fruit was highest (21.33±3.21°Brix) and thus can be preferred to develop beverages products from the fruit. A considerable amount of pectin was present 0.94±0.10%, 0.64±0.07%, 1.55±0.05% and 0.43±0.07% in the selected minor fruits - Nagatenga (Rhus semialata), Leteku (Baccaurea sapida), Poniol (Flacourtia gangomas) and Kujithekera (Garcinia cowa) respectively which are enough to develop jelly but due to pH below 3.0, fruits other than Poniol (pH -3.28±0.15) do not produce good jelly. The selected minor fruits are lauded for their pleasing flavor and colour as well as therapeutic properties and encompassed with most of the nutritional qualities. All the selected minor fruits Nagatenga (Rhus semialata), Leteku (Baccaurea sapida), Poniol (Flacourtia gangomas) and Kujithekera (Garcinia cowa) can be considered as good source of fibers (3.51±0.21 g/100g, 2.37±0.31 g/100g, 8.40±0.33 g/100g and 10.34±0.44 g/100g respectively), minerals (iron -26.33±1.15 mg, 7.16±1.44 mg, 29.83±1.44 mg and 15.16±2.25 mg per 100g respectively, calcium - 250.44±5.05 mg/100g, 143.24±4.00 mg/100g, 65.83±3.52 mg/100g and 192.81±2.44 mg/100g respectively and potassium - 111.0±7.0 mg/100g, 59.00±4.00 mg/100g, 44.00±3.00 mg/100g and 33.33±4.04 mg/100g, respectively), vitamins (ascorbic acid -216.66±14.40 mg, 24.16±7.21 mg, 43.33±7.21 mg and 67.78±3.40 mg per 100g of fruits respectively and carotenoids - 126.60±0.06 μg/100g, 50.76±0.99 μg/100g, 190.16±0.33 μg/100g and 890.33±0.94 μg/100g respectively) and phytochemicals (the total phenolic content-538.83±5.01 mg, 149.5±2.17 mg, 261.16±1.04 mg and 347.00±3.04 mg per 100g respectively, flavonoid - 246.45±21.55 mg, 44.64±5.61 mg, 87.17±2.70 mg and 98.03±2.01 mg respectively and total alkaloid - 104.00±13.52 mg, 170.33±5.77 mg, 143.33±7.09 mg and 156.33±1.52 mg respectively) as well as low in fat (1.02±0.05 g/100g, 0.66±0.09 g/100g, 0.88±0.10 g/100g and 0.25±0.02 g/100g, respectively). Based on the quality characteristics of the selected minor fruits, following products were developed namely – squash, spicy squash and sauce from Nagatenga (Rhus semialata), squash and RTS from Leteku (Baccaurea sapida), squash and jelly from Poniol (Flacourtia gangomas) and squash, candy and pickle from Kujithekera (Garcinia cowa). The acceptability of the products was determined through organoleptic evaluation using 9 point Hedonic scale by 10 panel judges and found highly acceptable, except the colour and appearancee of Nagatenga sauce was scored low (7 point). The chemical parameters namely TSS, acidity and pH of the products was evaluated and was within the range of FSSAI specification (squash TSS- ≥40 and acidity - ≤3.5, sauce TSS- ≥15 and acidity – ≥1, RTS TSS- ≥10 and acidity - ≥0.3, jelly TSS- ≥65 and acidity - 0.5-0.75 and candy TSS- ≥70). The nutrient content of the products was evaluated and found good amount of nutrients, that help to improve nutritional status of the people. The present investigation reveals that the RTS is more susceptible to spoilage due to high moisture content (89.04±1.13%) and low sugar content (11.93±0.28%) followed by the squashes. Whereas sugar based products jelly and candy have low moisture content (40.26±1.37% and 37.59±0.36% respectively) and good amount of sugar (75.01±3.06% and 90.47±5.69% respectively) may be considered to have long shelf life. Again pickle contain good amount of oil (17.56±1.86%) and salt which enhance quality retention thus increasing shelf life. The results as per physico-chemical parameters, sensory evaluation and microbial assay across storage reveals that in case of Nagatenga squash stored in glass bottle, plastic bottle and standing pouch are safe for consumption upto 180 days, 150 days and 60 days respectively. The Nagatenga spicy squash stored in glass bottle, plastic bottle and standing pouch showed a shelf life of 180 days, 150 days and 60 days respectively. The shelf life of Nagatenga sauce was 180 days in all the packaging materials. The shelf life of Leteku squash stored in glass bottle, plastic bottle and standing pouch are 180, 180 and 150 days respectively. The Leteku RTS can be consume safely upto 30 days when stored in glass bottle and get spoiled in other two packaging material on the 30 days of storage. The shelf life of Poniol squash stored in glass bottle and plastic bottle are upto 180 days and when stored in standing pouch the shelf life is till 150 days. The Poniol jelly stored in all the three packaging material showed acceptable shelf life across the entire storage period. The Kujithekera squash stored in glass bottle, plastic bottle and standing pouch are at safe and consumable state upto 180, 180 and 90 days of storage respectively in terms of physic-chemical evaluation. The Kujithekera candy was safe and within acceptable quality during all the storage period (0-180 days) stored in the all the three packaging material. The results depicts that in terms of sensory, physico-chemical (Significant at P < 0.05) and microbial evaluation of the developed products in different packing material across storage it can be concluded that glass bottle packaging is the best packaging materials for storing both liquid and solid products due to its highly inert, durable and chemical resistant properties. Plastic bottle can be considered next to glass bottle in terms of light weight and easy to handle properties and this packaging material also showed less prominent spoilage characters compared to standing pouch.
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    ThesisItemOpen Access
    PROCESSING AND VALUE ADDITION OF JACKFRUIT (Artocarpus heterophyllus. Lam.)
    (AAU, 2015) Baruah, Barnali; Dr Mridula Saikia Barooah
    A series of laboratory experiments were carried out to study the prospects of processing and value addition of jackfruit (Artocarpus heterophyllus Lam). Initially, five widely grown indigenous jackfruit genotypes of Assam i.e. Dhol Kathal, Nohoru-phutia Kathal, Pat-kathal, Mridongia Kathal and J-5 were collected and among these, Dhol Kathal having superior pulp quality and seed yield, which was selected for further evaluation. The study was confind under four well defined separate aspects i.e. 1) Study on physico-chemical composition of jackfruit seed and pulp 2) Standardization of seed-flour extraction process and quality assessment of seed-flour stored in different packaging materials 3) Incorporation of jackfruit seed flour in different baked products and study of their quality characteristics 4) Standardization of processing methods for jackfruit pulp-products and their quality assessment. Crude protein, crude fat, ash, crude fiber, iron and total sugar contents of jackfruit pulp was recorded to be 1.74 (g/100g), 0.28 (g/100g), 1.26 (g/100g), 1.30 (g/100g), 0.70 (mg/100g) and 18.52 (g/100g) respectively, whereas for seed these were 9.18 (g/100g), 1.28 (g/100g), 1.34 (g/100g), 1.68 (g/100g), 1.84 (mg/100g) and 7.32 (g/100g) respectively. Two different seed flour extraction methods for raw (Flour I) and heat processed seeds (Flour II) were standardized. Between Flour I and Flour II, no significant difference in nutrient contents was observed, however, they differed significantly in their functional properties. Heat processing significantly improved the functional properties rendering the Flour II suitable for use in bakery industry. Flour I and Flour II were further stored for 180 days in three different packaging materials viz. Laminated Aluminum (LA) foil pouches (100G), Polyethylene tetraphthalate (PET) containers and Poly propylene (PP) pouches (100 microns). The moisture content of Flour I stored in PP pouch was increased from 6.09% to 14.14% whereas in Flour II it was increased from 6.13% to 11.77%. In all the packaging materials, Flour II exhibited better storage quality. This flour can be stored safely for 180 days in LA foil pouches, 90 days at PET container and PP pouches, whereas Flour I can be kept better only for 90 days and 30 days in LA foil pouches and PP pouches, respectively. Wheat flour was successfully substituted up to 50% and 60% by Flour II in biscuits and cakes respectively with acceptable sensory qualities. Nutritional and sensory qualities remained unaltered up to 180 days and 30 days in Flour II incorporated biscuits cakes respectively. Processing methods of toffee, leather and jam prepared from jackfruit pulp were standardized. With the increase in pulp percentage in jackfruit toffee, a marked decrease in sensory scores (texture, hardness, taste, smell and over all acceptability) were observed. Toffee with 10% jackfruit pulp recorded the highest mean sensory score (7) for overall acceptability. Though there was a significant change in moisture content of toffee from initial (7.73%) to 180 days storage (8.63%) period, the other nutritional and sensory parameters showed no significant change during storage. The texture of the leather was not affected by the increase in sugar content, however 5% added sugar level got the highest sensory score for taste (8.8) as compared to 10% (6.6) and 15% (5.4) level in 9 point Hedonic scale. Drying method had a pronounced impact on the moisture content, taste and aroma of jackfruit leather. The sundried leather had a higher percentage of moisture content (12.56) as compared to oven dried (9.38) one. Moreover, the sundried leather obtained a significantly lower sensory score. Jackfruit leather was found to be a shelf stable product in terms of nutritional and sensory quality. The processing method for jackfruit jam was standardized to meet the FPO specification for fruit jam. The sensory and nutritional qualities were observed to be intact during 180 days of storage period. From the study it can be concluded that there is immense scope for product development from jackfruit and enhancing farm income through entrepreneurship and industrial exploitation of the fruit.