International Journal of Advanced Science and Technology Vol. 29, No. 7, (2020), pp. 5078-5083 Evaluation of cooking and sensory attributes of selected South Indian rice land races Chitra Kalaichelvan1*, S.Babu2 1*Assistant Professor, VIT School of Agricultural Innovations and Advanced Learning, Vellore Institute of Technology, Vellore, India. Email: [email protected] 2Professor and Dean, VIT School of Agricultural Innovations and Advanced Learning Vellore Institute of Technology, Vellore, India. Email: [email protected] Abstract There is an increased interest in usage of traditional rice landraces amongst the educated urban population of South India due to its varied health benefits. The current study was undertaken with nineteen parboiled rice landraces available in South India along with White Ponni (a popular hybrid variety of Taichung65 and Myang Ebos 6080/2) as the control. Cooking characteristics and sensory evaluation of these varieties were studied. The results showed that the traditional landraces are liked by the sensory panel. Besides, the texture analyser attributes of the rice land races were comparable with that of the White Ponni. The cooking trails revealed that most of the landraces tested had similar cooking time when compared with the control. A few landraces had similar volume of expansion as that of White Ponni. Keywords: Cultivation, Land races, Traditional rice, Cooking characteristics, Rice texture, Texture analysis, Statistical analysis, 1 INTRODUCTION Amongst the varied reasons, consumption of polished rice seems to play a prominent role in developing obesity and diabetics in India. Though rice has been the staple food for South Indians, the prevalence of the life style diseases was not prominent during the 60’s. During the pre-independence era, sustenance farming practices were predominant. Farmers were the custodians of seeds of traditional land races. These landraces possessed certain traits to overcome biotic and abiotic stress, besides catering to the human nutrition and good health [1][2]. With the advent of Green Revolution and advancements in the milling technology, the South Indian population favoured polished white rice over hand pound coloured rice as their staple food. This shift coupled with sedentary lifestyle paved way for the increase incidence of Diabetics among the urban Indian population. In this context, there is a renewed interest in the use of traditional rice landraces by the Indian consumers owing to its enhanced nutritional properties. In a consumer survey conducted among Chennai (South India) population, a slight change in the preference of partially milled rice as against fully milled white rice for health reasons was noted among the consumers. Further, the major hurdle in acceptance of colored rice was its appearance, hard texture and longer cooking time. In this study people were willing to change to unmilled brown rice or partially milled brown rice provided it is cost effective and its health benefits are significant [3]. Consumer preferences are assessed by either using descriptive lexicons or by hedonic testing. [4] developed lexicons for rice flavour, while [5] described lexicons for texture. Various surveys conducted amongst the rice eating population are inconclusive on the consumer demands due to complex interplay of extrinsic ( culture, organic production, geographical area) and intrinsic factors(nutritional content, appearance, texture flavour attributes) of cooked and raw rice. Inherent subjectivity combined with cost and time constraints of sensory panel led to increased usage of instrumental analysis to assess the cooking quality of rice. It has been observed that the results from the compression or extrusion tests can be aanalysed through multiple regression to obtain reliable data ISSN: 2005-4238 IJAST 5078 Copyright ⓒ 2020 SERSC International Journal of Advanced Science and Technology Vol. 29, No. 7, (2020), pp. 5078-5083 on the rice hardness and adhesion to lips[6] while the consistency coefficient (K*) of frequency sweep test in dynamic rheological testing gave reliable correlation to sensory hardness [7]. The increasing cultivation of the rice landraces in various parts of India, along with the inadequacy of biochemical parameters to predict the eating quality of rice, necessitates a systematic study of all the individual landraces for the comparison of sensory data from the local consumers and instrumental (texture and rheology) data, so that a universal selection criteria can be established. In this context, around nineteen South Indian landraces were undertaken for this study. 2 MATERIALS AND METHODS Parboiled and polished White Ponni rice and parboiled, dehulled Brown Ponni rice were purchased from local store at Vellore, India and the rest of the parboiled, dehulled, unpolished traditional rice varieties used in this study were obtained from a FPO (farmers’ producer organisation), Sempulam Sustainable Solutions, Chennai, India. The rice packets were stored at 4℃ until further analysis. 2.1 Studies on cooking attributes Cooked weight, cooked volume, volume of expansion, and cooking time for all the varieties were calculated by cooking five gram of each variety in boiling test tubes with required amount of distilled water for cooking of rice to correct consistency [8]. Each variety had three replicates and the cooking trail was repeated twice. 2.2 Texture Analysis of cooked rice All the rice varieties were washed and soaked for thirty minutes in water and pressure cooked with pre-calculated water. Three replicates of each variety were subjected to texture analysis. Five measurements were taken for each variety. The cooked rice samples were analysed immediately for textural characters using Texture Analyser (TA.HD plus) along with the Texture Exponent 32 data acquisition software (Stable Micro Systems Ltd., Surrey, England).The testing conditions were optimised before taking the sample reading. A 5kg load cell was used. Double compression test (40%) was performed on the rice samples with P/75 probe with test speed of 10mm per sec. 2.3 Sensory analysis of cooked rice All the rice varieties were cooked in the same way as for the texture analyser. Attributes such as flavour, texture, taste and overall acceptability was assessed using modified Hedonic scale rating test with 21 semi-trained participants. Rice samples were assigned random numbers and presented in pre- heated glass bowls covered with watch glass. Rice samples were tested in a batch of five and the participants were asked to rinse their mouth with water after assessing each sample. 2.4 Statistical analysis Statistika Version 13.3 was used to analyse the experimental data for standard deviation and correlation. Sensory data were converted into corresponding numbers and the resulting data were plotted on radar charts using Origin Version 2019. 3 RESULTS AND DISCUSSION The cooking parameters of landraces and the White Ponni are shown in Figure 1.The maximum expansion in volume of cooked rice was observed in the control (White Ponni) (Table 1). Cooking characteristics of rice depends on many factors like variety, preliminary paddy processing (parboiling), degree of milling, chemical composition, storage time and conditions of rice. Besides the mass and heat transfer varies with different cooking methods also. In general, polished white rice expands three times and the results obtained were in concordant to the common observed phenomenon. When compared with the control, the percentage expansion among the traditional rice ISSN: 2005-4238 IJAST 5079 Copyright ⓒ 2020 SERSC International Journal of Advanced Science and Technology Vol. 29, No. 7, (2020), pp. 5078-5083 varieties was highest in Karuppu Kowni (95.3%), followed by Vellaikar (88.13%), Kattu Kuthalam (87.24%) and Karunkuruvai (84.4%). Greater volume of expansion is preferred by customers in lower economic strata and in commercial use since less quantity of raw rice is required. Hence, the afore- mentioned varieties can be easily substituted for the currently used polished rice. Volume expansion has been reported to play no role in sensory property of rice [9]. Mathimuni took ten minutes more to cook when compared with White Ponni. All the other varieties displayed similar cooking time to that of control. Fig. 1. Cooked rice land races used for the study (1-kapakar; 2-karunkuruvai; 3-karuppu kowni; 4- kattu kuthalam; 5-koomvazhai; 6-kuzhiadichan; 7-kullakar; 8-mappilai samba; 9-mathimuni; 10- neelan samba; 11-njavara; 12-poovan samba;13-pisini; 14.sigappu kowni; 15-soorankuruvai; 16- vaigunda; 17-vellaikaar; 18-white ponni; 19-illupai poo samba; 20-brown ponni) TABLE.1. Cooking characters of the some traditional South Indian landraces Traditional rice varieties Cooked Cooked Volume of Cooking weight (g) Volume (ml) expansion (ratio) time(minutes) 1-KAPAKAR 25.83±0.76 18.67±0.29 2.44±0.05 54±1.08 2-KARUNKURUVAI 28.33±2.08 23.17±1.15 3.09±0.15 56±1.10 3-KARUPPU KOWNI 35±1.00 26.67±0.58 3.49±0.20 54±1.23 4-KATTU 56±1.02 KUTHALAM 31±0.00 23.33±1.04 3.18±0.16 5-KOOMVAZHAI 22.33±0.58 17.83±1.15 2.38±0.15 55±1.34 6-KUZHIADICHAN 22.33±0.58 18.67±1.04 2.55±0.20 54±1.47 7-KULLAKAR 22.33±1.15 18.5±0.87 2.58±0.02 53±1.00 8-MAPPILAI SAMBA 22±1.00 17.67±0.58 2.52±0.08 53±1.47 9-MATHIMUNI 22.67±1.53 19.33±1.04 2.64±0.15 62±1.48 10-NEELAN SAMBA 22.67±0.58 20.83±0.58 2.78±0.08 54±1.50 11-NJAVARA 23±0.00 17.83±0.29 2.38±0.17 57±1.35 12-POOVAN SAMBA 22±1.00 18±0.50 2.46±0.12 56±1.52 13-PISINI 22±2.65 15.83±1.15 2.11±0.15 52±1.11 14.SIGAPPU KOWNI 24±1.00 18.33±0.29 2.63±0.20 54±1.36 15- 58±1.27 SOORANKURUVAI 23.67±1.15 19.67±0.58 2.81±0.08 16-VAIGUNDA 27.67±1.15 20±1.50 2.73±0.23 57±1.43 17-VELLAIKAAR 28.67±2.08 24.67±1.26 3.22±0.07 58±1.18 18-WHITE PONNI 31.83±0.76 26.17±1.53 3.66±0.12 51±1.52 19-ILLUPAI POO 52±1.40 SAMBA 24±0.00 17.83±1.04 2.28±0.13 20-BROWN PONNI 27±1 22.13±1.96 3.07±0.12 54±1.26 The values in each column represent mean ± standard deviation.