Development of continuous processing method for pouches in rotary retorts

Caufield, Haley

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https://hdl.handle.net/2142/46606 Copy

Description

Title

Development of continuous processing method for pouches in rotary retorts

Author(s)

Caufield, Haley

Issue Date

2014-01-16T17:56:00Z

Director of Research (if dissertation) or Advisor (if thesis)

Lee, Youngsoo

Department of Study

Food Science and Human Nutrition

Discipline

Food Science and Human Nutrition

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• retort pouches
• rotary retorts
• residual gas volume

Abstract

The benefits of retort pouches compared to metal cans include a smaller weight and volume and an easier and safer opening process. Decreasing the weight and volume would improve the packing and shipping efficiency of Unitized Group RationsTM. Metal cans are efficiently processed in continuous retorts; however, pouches are not compatible with these continuous retorts and must be processed in less efficient batch retorts, resulting in higher operating costs. The overall objective of this study was to supply vegetables packaged and processed in retort pouches for UGRTM packages at a lower cost. The overall objective consisted of three specific aims. The first aim of this study was to develop a retort pouch and a stainless steel container to be processed in existing rotary retorts, increasing processing efficiency at a minimal cost to the processor. The second aim was to determine if the developed retort pouches and stainless steel containers processed in existing continuous rotating retorts can be a viable alternative to pouches processed in less efficient batch retorts. The third aim was to evaluate the effect of product viscosity and residual gas volume in the pouch on the processing time. In order to accomplish these objectives, processed green beans in three packaging options, the developed rotating pouch, a No. 10 can, and an institutional size pouch, were compared in consumer acceptance and physical properties directly after processing and after six months of storage at 100°F. Results of the consumer acceptance tests showed that there was no difference in consumers’ overall liking of the three green bean samples directly after retorting. After six months, consumers rated the green beans from the No. 10 can higher in overall liking than the green beans from either type of pouch. To investigate the effect of viscosity and residual gas volume on processing time, the processing times of rotating pouches and No. 10 cans filled with two different amounts of tomato concentrates were compared. All packages filled with the higher amount of product had significantly lower residual gas volumes than the packages filled with the lower amount of product. The processing times decreased by lowering the product fill by 10% for both the rotating pouches and the No. 10 cans, especially with the more viscous concentrates. Decreasing the product fill led to an increase in residual gas volume, which increased agitation. The findings of this study show that it is possible to process pouches in existing retorts designed for No. 10 cans. Increasing the residual gas volume in rotating pouches can shorten processing times for liquids with higher viscosities due to enhanced agitation. Due to the widespread use of continuous rotary retorts and the advantages and growing popularity of retort pouches, food manufacturers may benefit by using stainless steel baskets for restraining pouches during rotary retorting as an alternative to investing in new pouch compatible retorts.

Graduation Semester

2013-12

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http://hdl.handle.net/2142/46606

Copyright and License Information

Copyright 2013 Haley Caufield

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