Characterization and production of resistant starch from culled banana to encapsulate fish oil | |
| Author | Nasrin, Taslima Ayesha Aktar |
| Call Number | AIT Diss. no.FB-13-04 |
| Subject(s) | Starch--Analysis Agricultural waste--Environmental aspects Encapsulation |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Food Engineering and Bioprocess Technology |
| Publisher | Asian Institute of Technology |
| Abstract | Agricultural waste pollutes our environment and health dangerously every day. Research regarding reuse or recycle of these wastes is an urge to get a sustainable society. Most of the agricultural waste, residues and by-products contain high amount of starch, cellulose, fat, protein and other bioactive compounds. These can be modified for better utilization in application of food, pharmaceutics, medicine, energy, textiles, agriculture, livestock etc as value-additions. Banana (Musa spp.) is the world’s 4th position dietary staple produced mostly in tropical and subtropical countries. Injured, undersized as well as neglected bananas called “cull” are rejected before packing. On the other hand, two-fifth of the total weight of fresh bananas is peels. These huge amounts of underutilized bananas (culls) and peels are disposed of improperly every day which make qualitative and quantitative losses and cause environmental pollution. Culled banana and its peel contains high amount of starch especially resistant starch (RS). Kluai Namwa variety (Musa ABB group) is the mostly grown banana in Thailand containing high amount of resistant starch and amylose. In this study, culled banana pulp starch, peel starch and peel flour were produced from culled green banana of Kluai Namwa variety and characterized to find out the suitable raw materials to produce resistant starch type III (RS III). Starch was extracted from culled banana pulp and peels by wet milling method using 0.05% (w/w) NaOH solution and dried in hot air oven at 40 °C. Banana peel flour was produced by drying the small pieces of peel in hot air oven at 40 °C, grinding and passing through 40 mesh sieve. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), pasting properties, swelling power (SP), solubility, water holding capacity (WHC), free thaw stability and chemical properties were analysed of culled banana pulp starch, peel starch and peel flour. Culled banana pulp starch was used in the next experiments to produce RS III as it contains the highest amount of RSII and amylose. RS III was produced by lintnerization of starch in three different concentrations of hydrochloric acid (HCl) and lintnerization followed by autoclaving. Maximum RS III was produced in culled banana pulp starch when it was treated with 2 N HCl followed by autoclaving treatment. But there was no significant difference (p < 0.01) in RS III content between native autoclaved starch and lintnerization followed by autoclaved starch. Culled banana pulp resistant starch (CBPRS) was used to stabilise fish oil (7.5% w/w and 5% w/w) emulsion with soy protein isolate (SPI) and compared with that produced by the mixture of Hylon VII and SPI and only SPI with same oil load. Emulsions made by the mixture of CBPRS and SPI was stable without any creaming off or phase separation up to 9 days in both oil loads where as that made with SPI only was destabilised on 5th days storing at 4 °C. In each emulsion, peroxide value (PV) and anisidine value (AV) was increased with increasing storage time, but the rate of increment was the highest in emulsion made by only SPI and 7.5% (w/w) fish oil and the lowest in that made by CBPRS, SPI and 5% (w/w) fish oil. The lowest score (1.2) of sensory quality (fishy smell) was obtained by the emulsions made by CBPRS and SPI, followed by 2.8 in that made with Hylon VII and SPI, 3.2 in that made with SPI only in 5% oil content and 7.8 in fish oil. The oil loads (33% and 50% w/w) of freeze dried fish oil microcapsules were produced by lyophilizing the previous emulsions. The highest encapsulation efficiency (EE), 82.49% was found in the microcapsule containing CBPRS, SPI and 33% fish oil, while the minimum was 70.78% in that containing SPI and 50% oil. Flow ability of the microcapsules made with the mixture of protein and RS was regarded as “poor flow” type and that made with only protein was “very poor flow” type by analyzing their bulk density (BD), tapped density (TD), compressibility index (CI), Hasner ratio (HR) and angle of repose (AR). Oxidative stability also suggested that the microcapsules contained the mixtures of CBPRS and SPI with 33% oil load was the most stable as it produced the lowest amount of PV and AV throughout the storage period. Functional muffins were prepared by using the fish oil emulsions containing the mixture of CBPRS and SPI and the mixture of Hylon VII and SPI. Muffins made with emulsions containing mixture of CBPRS and SPI was able to mask fishy flavour in a great extent than that containing mixture of Hylon VII and SPI. Overall acceptability of muffin made with emulsions containing mixture of CBPRS and SPI obtained the second highest score of 8.3, following control muffin (no fish oil). CBPRS may be used to produce slowly digestible, high fiber and low glycemic index bakery foods, noodles, cookies. Moreover, fish oil emulsions and microcapsules stabilized with CBPRS and SPI was stable with less fishy odour and less oxidised products up to 10 days and 10 weeks respectively at 4 °C storage temperature. So these fish oil- enriched emulsions or microcapsules can be incorporated into other different baking foods like bread, cake, biscuit, cookies etc. |
| Year | 2013 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Anal, Anil Kumar |
| Examination Committee(s) | Athapol Noomhorm;Datta, Avishek |
| Scholarship Donor(s) | National Agricultural Technology Project Phase 1/Bangladesh Agricultural Research Council (BARC) |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2013 |