Development and Evaluation of Functional Food Pasta

Abstract

<p>My PhD project, entitled "Development and Evaluation of Functional Food Pasta", mainly addresses the potential applications of technology at different scales for evaluating the functional food pasta. The project aimed to apply new concepts and engineering approaches involved in micro and nanotechnology to deliver bioactive compounds for the control of some of the chronic diseases.</p> <p>Major objectives of the study were: The development of functional pasta using different concentrations of selected potential functional ingredients with specific health value (targeting chronic diseases)" Evaluation of the technological quality of pasta using instrumental and sensory methods" Determining the quantity, quality and functional properties of uncooked, cooked, and partially digested pasta with enzymes <i>in vitro</i>" Understanding the structural changes at the micro and nano-scales in uncooked, cooked and digested pasta developed from various functional ingredients using techniques like Scanning Electron Microscopy (SEM), Confocal Laser Scanning Microscopy (CSLM), Nuclear Magnetic resonance (NMR), X-ray diffraction (XRD), Small-Angle X-ray Scattering (SAXS)" Determining structure function correlations in modified pasta through materials science characterisation.</p> <p>My work involved the development of pasta as a functional food by incorporation of ingredients such as Novelose 330 (RSIII), Hi-Maize 1043 (RSII), inulin, Barley Balance (β-glucan concentrate), bran and pollard in pasta formulations made from durum semolina. Semolina was mixed with ingredient at various concentrations and made into spaghetti. The cooked pasta was evaluated for quality and enzymatic <i>in vitro</i> starch hydrolysis</p> <p>Above mentioned techniques were effectively used further for a better understanding of structure-function correlations in each of these modified pasta. Among results obtained, substitution with RSII and RSIII to semolina had subtle affects on pasta quality at 10 % and 20% substitution whereas RSII starch substitution at 50% increased cooking loss (4-7%) and decreased pasta firmness and water absorption. Each of the resistant starches was found effective in lowering the reducing sugar release indicating that resistant starch could be a very useful additive. XRD diffractograms showed that both RSII and RSIII increased the crystallinity of the pastas.</p> <p>Substitution with Inulin had a minor impact on pasta quality, giving reduced firmness and higher cooking loss with increasing inulin content and some changes to sensory scores. Starch hydrolysis of the inulin pasta reached a minimum at 5% inulin then increased to higher levels than the control at 20% inulin. SEM and CSLM images of cooked pasta support the hypothesis that up to 5% inulin encapsulates the starch granules in a protective coat, while higher inulin appears to disrupt the starch/protein matrix. XRD diffractograms of digested sample showed that at 5% inulin the crystallinity was maximum.</p> <p>Substitution of semolina with 7.5, 15 and 20% β-glucan concentrate increased the β-glucan content from 0.3% in semolina to 6% in uncooked and 8% in cooked pasta. Pasta firmness and stickiness increased while the pasta was a yellow-brown colour. Pasta substituted with β-glucan had a very good impact in lowering the glycemic index. With an increase in β-glucan, an increase in thick protective coat matting was seen over starch granules in CSLM and SEM images.</p> <p>As far as insoluble fibres were concerned it was found that addition of bran and pollard strongly influenced the organoleptic characteristics, colour and textural attributes of pasta. No significant increase in cooking loss could be observed up to 30% addition of insoluble fibres like bran and pollard. Among results obtained, it could be concluded that pasta with bran and pollard is functionally superior in terms of increased antioxidant activity and total dietary fibre content. An increase in RSR was observed in pasta developed with pollard whereas <i>in vitro</i> starch hydrolysis didn‟t change significantly for bran enriched samples compared to control" suggesting bran inclusion does not affect the glycemic index of pasta. Microscopy images showed that pollard inclusion resulted in breakdown of the starch-protein continuum, thus increasing accessibility of starch degrading enzymes resulting in an increased level of RSR. X-ray diffractograms showed that crystallinity levels also did not change for pasta with bran substitutes whereas for pollard enriched samples a decrease in crystallinity with increase in pollard was observed supporting the disruption to the matrix.</p> <p>The results of the study demonstrate the importance of the gluten matrix in affecting the functional properties, mechanical strength and cooking quality of pasta.</p>