Review of the effects of different processing technologies on cooked and convenience rice quality

Abstract

19Background 20Commercially available convenience rice such as retorted, quick cooking or frozen rice suffers 21 from sensory deficiencies compared to home cooked rice. The mechanisms causing deterioration in 22 texture and flavour during convenience rice processing are, in many cases, poorly understood. 23 Scope and Approach 24This review describes pre-cooking methods including washing and soaking, cooking methods 25 including cooking in excess water, by absorption and by high pressure, and post-cooking 26 technologies including cooling, freezing, retorting, canning, drying and storage, as well as the 27 influence of each process on physical properties and sensory attributes of cooked rice. 28 Key findings and conclusions 29Water diffusion and starch leaching, which occur in many processing steps, are important factors 30 affecting cooked rice quality. Soaking saves energy by reducing cooking time. Cooking by 31 absorption increases stickiness, but does not ensure uniform moisture distribution compared to 32 cooking in excess water, thus is not applicable for rice manufacturers. Leached amylose during 33 soaking and cooking affects hardness and stickiness of cooked rice significantly. Non-thermal 34 treatments such as high pressure soaking and cooking has potential to improve rice sensory 35 M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPTAbstract 2 properties compared to high temperature treatments, which change colour and flavour of 36 convenience rice. Drying and freezing results in a porous structure resulting in spongy texture after 37 rehydration and thawing, respectively. During storage, starch retrogradation deteriorates texture, but 38 can be retarded by high pressure processing or storage below the glass transition temperature. Much 39 is known about processing factors that affect freshly cooked rice, but more substantial knowledge of 40 how processing steps affect the structure property relationships and sensory properties of 41 convenience rice will assist manufacturers to specifically design products to meet the ever growing 42 consumer demands for convenience food. 43 44

Comparison of a Double Compression Test for the Prediction of Sensory Texture Attributes of Cooked Rice to a Single Compression Test

“…First of all, it was decided to analyze the correlation between the intact milled rice kernel size (length, width, and thickness) and the instrumental parameters of hardness and stickiness, which have been reported to be the most dominant attribute in affecting cooked rice texture (Yu et al, 2017). These correlations were assessed because the cooked rice kernel dimensions could influence the reaction forces observed during instrumental testing.…”

Volatile compounds profile of Brazilian aromatic brown rice genotypes and its cooking quality characteristics

“…Cooking time of rice can be affected by factors including grain moisture content, grain composition (mainly related to amylose and protein characteristics), cooking procedure, and processing methods (Yu, Turner, Fitzgerald, Stokes, & Witt, 2017). Higher cooking times are known to be a result of the greater extent of amylose-amylose, amylose-amylopectin, and starch-protein interactions that hamper the water absorption ability of brown rice and increase the time required for starch gelatinization (Li & Gilbert, 2018).…”

Effect of Atmospheric Packaging Method on Quality of Ready-to-eat Cooked Rice from IR 64 Rice (Oryza sativa L. indica)

“…This was attributed to browning enzymatic that probably happened in cooked rice. Polyphenol oxidase was one of the enzyme which responsible to this phenomenon (Yu et al, 2017). pH analysis Generally, cooked rice has a neutral pH (± 7) , the taste of freshly cooked rice was sweet and creamy taste.…”