The development of expanded snack product made from pumpkin flour-corn grits: Effect of extrusion conditions and formulations on physical characteristics and microstructure

Pumpkin products confer natural sweetness, desirable flavours and β-carotene, a vitamin A precursor when added as ingredients to extruded snacks. Therefore, a potential use for dried pumpkin flour is as an ingredient in ready-to-eat (RTE) snack foods. Growth in this market has driven food manufactur...

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Published in:Foods
Main Author: Nor N.M.; Carr A.; Hardacre A.; Brennan C.S.
Format: Article
Language:English
Published: MDPI AG 2013
Online Access:https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007231177&doi=10.3390%2ffoods2020160&partnerID=40&md5=1c1260fb4879100329963e363262438d
id 2-s2.0-85007231177
spelling 2-s2.0-85007231177
Nor N.M.; Carr A.; Hardacre A.; Brennan C.S.
The development of expanded snack product made from pumpkin flour-corn grits: Effect of extrusion conditions and formulations on physical characteristics and microstructure
2013
Foods
2
2
10.3390/foods2020160
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007231177&doi=10.3390%2ffoods2020160&partnerID=40&md5=1c1260fb4879100329963e363262438d
Pumpkin products confer natural sweetness, desirable flavours and β-carotene, a vitamin A precursor when added as ingredients to extruded snacks. Therefore, a potential use for dried pumpkin flour is as an ingredient in ready-to-eat (RTE) snack foods. Growth in this market has driven food manufacturers to produce a variety of new high value snack foods incorporating diverse ingredients to enhance the appearance and nutritional properties of these foods. Ready-to-eat snacks were made by extruding corn grits with 5%, 10%, 15% and 20% of pumpkin flour. Snacks made from 100% corn grits were used as control products for this work. The effect of formulation and screw speeds of 250 rpm and 350 rpm on torque and specific mechanical energy (SME, kWh/kg), physical characteristics (expansion ratio, bulk density, true density and hardness) and the microstructure of the snacks were studied. Increasing the screw speed resulted in a decrease of torque for all formulations. When pumpkin flour was added the specific mechanical energy (SME) decreased by approximately 45%. Increasing the percentage of pumpkin flour at the higher screw speed resulted in a harder texture for the extruded products. X-ray tomography of pumpkin flour-corn grit snacks showed that increased levels of pumpkin flour decreased both the bubble area and bubble size. However, no significant differences (p > 0.05) in bubble wall thickness were measured. By understanding the conditions during extrusion, desirable nutritional characteristics can be incorporated while maximizing expansion to make a product with low bulk density, a fine bubble structure and acceptable organoleptic properties. © 2013 by the authors; licensee MDPI, Basel, Switzerland.
MDPI AG
23048158
English
Article
All Open Access; Gold Open Access; Green Open Access
author Nor N.M.; Carr A.; Hardacre A.; Brennan C.S.
spellingShingle Nor N.M.; Carr A.; Hardacre A.; Brennan C.S.
The development of expanded snack product made from pumpkin flour-corn grits: Effect of extrusion conditions and formulations on physical characteristics and microstructure
author_facet Nor N.M.; Carr A.; Hardacre A.; Brennan C.S.
author_sort Nor N.M.; Carr A.; Hardacre A.; Brennan C.S.
title The development of expanded snack product made from pumpkin flour-corn grits: Effect of extrusion conditions and formulations on physical characteristics and microstructure
title_short The development of expanded snack product made from pumpkin flour-corn grits: Effect of extrusion conditions and formulations on physical characteristics and microstructure
title_full The development of expanded snack product made from pumpkin flour-corn grits: Effect of extrusion conditions and formulations on physical characteristics and microstructure
title_fullStr The development of expanded snack product made from pumpkin flour-corn grits: Effect of extrusion conditions and formulations on physical characteristics and microstructure
title_full_unstemmed The development of expanded snack product made from pumpkin flour-corn grits: Effect of extrusion conditions and formulations on physical characteristics and microstructure
title_sort The development of expanded snack product made from pumpkin flour-corn grits: Effect of extrusion conditions and formulations on physical characteristics and microstructure
publishDate 2013
container_title Foods
container_volume 2
container_issue 2
doi_str_mv 10.3390/foods2020160
url https://www.scopus.com/inward/record.uri?eid=2-s2.0-85007231177&doi=10.3390%2ffoods2020160&partnerID=40&md5=1c1260fb4879100329963e363262438d
description Pumpkin products confer natural sweetness, desirable flavours and β-carotene, a vitamin A precursor when added as ingredients to extruded snacks. Therefore, a potential use for dried pumpkin flour is as an ingredient in ready-to-eat (RTE) snack foods. Growth in this market has driven food manufacturers to produce a variety of new high value snack foods incorporating diverse ingredients to enhance the appearance and nutritional properties of these foods. Ready-to-eat snacks were made by extruding corn grits with 5%, 10%, 15% and 20% of pumpkin flour. Snacks made from 100% corn grits were used as control products for this work. The effect of formulation and screw speeds of 250 rpm and 350 rpm on torque and specific mechanical energy (SME, kWh/kg), physical characteristics (expansion ratio, bulk density, true density and hardness) and the microstructure of the snacks were studied. Increasing the screw speed resulted in a decrease of torque for all formulations. When pumpkin flour was added the specific mechanical energy (SME) decreased by approximately 45%. Increasing the percentage of pumpkin flour at the higher screw speed resulted in a harder texture for the extruded products. X-ray tomography of pumpkin flour-corn grit snacks showed that increased levels of pumpkin flour decreased both the bubble area and bubble size. However, no significant differences (p > 0.05) in bubble wall thickness were measured. By understanding the conditions during extrusion, desirable nutritional characteristics can be incorporated while maximizing expansion to make a product with low bulk density, a fine bubble structure and acceptable organoleptic properties. © 2013 by the authors; licensee MDPI, Basel, Switzerland.
publisher MDPI AG
issn 23048158
language English
format Article
accesstype All Open Access; Gold Open Access; Green Open Access
record_format scopus
collection Scopus
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