Introduction

Ocimum basilicum.L (Basil) is one of the endemic plants and its seed is especially used for its pharmaceutical property¹.This plant is grown in many parts of the globe chiefly in warm regions of Asia, Africa, and Central and South America. Besides its use as a standard medicine, basil seeds are commonly incorporated into food products, like puddings, sweets, ice-creams and liquid refreshments, and are used as a source of dietary fiber. Basil seeds contain 9.19% moisture, 17.32% crude protein, 9.68% crude fat, 5.80% ash, 7.11% fiber, 50.9 % carbohydrates and 63.78±1.75 mg GAE/g of total phenolic content².

Basilseeds  are  proven  to  have  good  antimicrobial,  antioxidant  and  anticancer  activities.Bioactivity of  O.basilicum seeds  has  projected  the  great  importance of functional foods³.

Idli being a fermented and steamed food, contributes to wholesome meal with sufficient carbohydrates, source of protein and B-Complex vitamins⁴ and has been accepted as a healthy breakfast for all ages by the different health organizations, including WHO. The main ingredients in Idli are rice and black gram. The synergistic interactions between the polysaccharides, starch and mucilage in black gram, results in an enhanced foam stability during and after fermentation, and also the increased viscosity offers a spongy porous⁵ steamed rice cake.

The rising popularity of O.basilicum seeds and its gelatin-like consistency, has created an interest to use these seeds as an effective ingredient to enrich the steamed rice cakes^6. It has also been reported that the polysaccharides proportion of basil seeds namely glucomannan, xylan, glucan and the presence of a highly branched arabinogalactan⁷ contribute to the mucilaginous or gelatin like property. This property of the basil seed is utilized in the steamed rice cake preparation, instead of black gram, which is a prime ingredient and a causative factor for obtaining a soft textured steamed rice cake⁸.

Even though, most breakfast grains and traditional food items have a unique place with the power pack of nutrients⁹, the misfortune is that they are categorized as carbohydrate rich foods, and this is applicable for steamed rice cake too. Hence, this study has been devised with the primary objective of preparing value added steamed rice cakes by incorporating various proportions of unprocessed and processed basil seeds and also, to analyse the proximate, textural and sensory characteristics and its acceptance in comparison with the control steamed rice cake.

Materials and Methods

Selection of Samples

The raw materials required for the study such as parboiled rice (Oryza sativa), dehulled black gram (Vigna mungo) and basil or sabja seeds (Ocimum basilicum L.), were purchased from the local market of Salem district, Tamilnadu. The ingredients rice and dhal were hand sorted, to make sure that only quality grains are used and the impurities were removed by washing with water. The basil seeds were hand sorted and sieved to ensure quality.

Formulation of Ocimum basilicum L.  Seed Incorporated Steamed Rice Cake

The cleaned parboiled rice and dehulled black gram were soaked separately in the ratio of 4:1 (100g,25g) for control and different proportions for respective variations, as depicted in Table-1 for 5 hrs in water at room temperature¹⁰.The rice was ground coarsely, while black gram to a fine batter with requisite amount of water for grinding. Salt was added as required for taste and the batter was allowed to ferment for 7 hours¹¹. For variations V1, V2, V3 and V4 raw basil seeds of 1.25g, 2.5g, 3.75g and 5g were added respectively in the batter. Meanwhile, the basil seeds for variations V5, V6, V7 and V8 (1.25g, 2.5g, 3.75g and 5g) was dry roasted at 115⁰ C for 6-8 minutes and cooled, roasting beyond this temperature charred the seeds, while roasting lesser than 115⁰ C did not bring about changes in the colour and  aroma. The basil seeds required for the variations V9 (1.25g), V10 (2.5g), V11 (3.75g) and V12 (5g) was steamed for 8-10 minutes.  The batter was beaten well and basil seeds (unprocessed and processed) at 5, 10, 15, and 20% levels of black gram were incorporated into the respective proportions of batter and was allowed to stand for a period of 15 minutes¹², for the seeds to gel. Soaking for a longer period of time will result in unfavorable batter consistency. About 40ml of the batter with appropriate proportion of basil seed for each variation was poured in an Idli steamer and steamed till doneness which approximated to 5 to 8 minutes¹³. The O. basilicum seed incorporated steamed rice cake is done. Simultaneously the control steamed rice cake was prepared by following the same procedure without the addition of basil seeds.

Table 1: Ingredients for the Preparation of Different Variations of Steamed Rice Cake

Proximate Analysis

Proximate composition such as moisture, ash, fat, protein and fiber of unprocessed, roasted and steamed basil seeds incorporated steamed rice cake was determined according to the standard procedures. The standard procedures recommended by FSSAI (2016)¹⁴ for cereal and cereal products, was used as a test method for determination of moisture, ash and fibre and fat. The FAO (2002)¹⁵ procedure was used to determine the amount of calories present in the developed product.

Texture Profile Analysis           

The Texture Profile Analysis (TPA) test  consists  of  compressing  a  bite-size  piece  of  steamed rice cake  two  times  in  a  reciprocating  motion  that  imitates  the  action  of  the  jaw. The  texture  of  each  steamed rice cake was  analyzed  using  P/25mm  compression  plate in  Texture Analyzer (Perten Instruments, Sweden). The steamed rice cake was cooled to room temperature and was cut into an inch cube using an inch cubic mould. The extra top and bottom layers were sliced off to make the steamed rice cake fit to the mould. The cut piece was placed on the heavy duty platform and the test speed was set to 5mm/sec and the probe compressed a distance of 10 mm of the cut steamed rice cake to get the TPA of the steamed rice cake. Parameters like peak force, stringiness, stickiness, adhesiveness, springiness, cohesiveness, chewiness and gumminess has been calculated based on the force deformation curves, captured as a graph and stored in separate projects/files for analysis and export to spreadsheet programs¹⁶.

Organoleptic Analysis

The organoleptic characteristics of the different variations of prepared steamed rice cake was determined using 120 panelist. All members were familiar with the steamed rice cake as it is a common and frequently consumed food. The samples of uniform size and shape were coded with random numbers. The panelists were asked to score and comment on the color, appearance, texture, mouth feel, taste, flavour and overall acceptability. These sensory attributes were measured on a 9-point hedonic scale with the highest score being extremely good and the lowest being poor.

Statistical Analysis

All experiments in the present analysis were conducted in triplicate, and mean values were reported. The descriptive statistical analyses were performed using IBM SPSS Statistics 16 Software package. The data were subjected to analysis of variance (One-way ANOVA) with Duncan’s Post Hoc test (P<0.05) to determine the significant difference between the means.

Results and Discussion

Proximate Analysis

The processing methods are employed to enhance the sensory characteristics like aroma and texture. Food processing also improve the nutritional and antioxidant values by reducing the anti-nutritional factors, destruction of seed microflora, improving the carbohydrate and protein digestibility, increasing the prebiotic dietary fiber, shelf life and consumer acceptance of the developed value-added dietary products¹⁷. To trace the difference in the acceptability and nutritional parameters the processing methods like roasting and steaming were done along with the utilization of raw O.basilicium seeds for developing value added Idlis.

The results of proximate analysis presented in Table-2 is discussed herewith. The moisture content of the raw O. basilicum seeds incorporated steamed rice cakes ranged from 57.72 to 63.91%, which shows a gradual decrease of moisture content in variations. The decrease in moisture content is proportional to the increase in the quantity of basil seeds, which may be attributed to the water holding capacity of basil seeds¹⁸. The moisture percentage was found least in the roasted variations, as the roasting time and temperature play a vital role in moisture control¹⁹. The steamed rice cake variations V9 to V12 with steamed basil seeds projected more moisture, V9 showing the highest percentage 69.33. The cause of increased moisture being, during steaming a certain proportion of steam was absorbed by the seeds, as the basil seeds have more affinity to water²⁰. Moisture is an important parameter in the quality and acceptability of food products, as it influences texture and affects the shelf life and microbial growth throughout storage²¹.

Table -2 indicates that the calorie content of the variations has significantly increased when compared to control product. It should also be pointed that the variations with roasted basil seed provided more calories ( 141-159 Kcals) than the control (139.14 Kcals) followed by the raw seeds incorporated steamed cakes(137.17-151.55 Kcals), while the steamed basil seeds incorporated variations of steamed rice cakes provided lesser calories( 113-115 Kcals), which proves similarity with the results of Uche Samuel Ndidi etal²².

Protein composition of all the variations of steamed rice cake has increased marginally when compared to control as the raw basil seeds contribute to 17 to 20% of protein, which is twice more than that of the contribution from black gram. Of all, the roasted basil seeds incorporated steamed rice cake projects more protein, which is also justified by the study of Olawepo etal²³.

Results on ash reveal that on comparison with the control steamed rice cake, the processed as well the unprocessed variations have higher ash content. Ash content increment is an indication of the level of mineral composition of the substrates²⁴. The 20% roasted basil seed incorporated variation, V8 records highest percentage (1.81%) of ash, which may be due to the fact that roasting retains more nutritents²⁵. The fat percentage was more in the roasted basil seeds incorporated variation, while steaming has reduced the fat.

It is evident from Table -2 that, the fiber content has shown a drastic increase in the highest proportion of roasted basil seed incorporated variation V8, favouring the nutritional profile. A similar effect of increased fibre on dry roasting of chia seeds has also been reported²⁶. The dietary fibre in basil seeds regulate blood sugar levels and proves beneficial for Type 2 diabetes²⁷. It may be correlated to the fact that the presence of fibre in the roasted basil seeds steamed rice cake could increase the micro flora population that uses fiber in their metabolism and would prove to be a promising source of prebiotic ²⁸.

It is also important to understand that combination of foods or food groups improve the nutritional value of meal and elicits a positive outcome on post prandial blood glucose levels²⁹. Hence this amalgamation of O. basilicum seeds into high glycemic indexed Idlis may decrease post prandial glycemic response which can be proved by clinical trials.

Table 2: Mean Proximate Analysis of the Raw, Roasted and Steamed Ocimum basilicum L. Seeds Incorporated Steamed Rice Cake

Each value in the table are represented as Mean ± SD (n=3). Statistically significant at p < 0.05, where ^a<b<c<d<e<fin each column. Different superscripts denote significant difference at (p<0.05).

Texture Profile Analysis of the raw, roasted and steamed Ocimum basilicum L. seeds incorporated steamed rice cake is presented in Table-3.

Results of Table-3 has shown that there was a significant difference (p<0.05) in the hardness of the basil seed incorporated steamed rice cake prepared from different variations. Firmness or hardness which has been represented by peak force A, increased with the increase in basil seed proportion. Greatest hardness was noticed in variation 12. Lower the hardness softer is the Idli³⁰. The hardness may be correlated with the moisture percentage of the steamed rice cakes, as well the level of incorporation of carbon dioxide, which could have been hampered because of the intact packaging of the seeds.

Stickiness is the force required to separate the material that sticks to the teeth while eating³¹. The stickiness ranged between -0.5 and -1.71 N. In this more stickiness was observed in V12 and lowest was found in V4. The gelation in the steamed basil seeds may be a contributing factor for more stickiness in V12. The lowest stickiness shows that the variation 4 -steamed rice cake has a good firm texture.

Springiness is related to fluffiness as it determines the extent of recovery between the first and second compression³².  Springiness ranged from 0.67 to 0.93 and there were significant differences in the springiness between variations and control sample (p < 0.05). Table 3 depicts that more springiness has been observed in roasted basil seeds incorporated steamed rice cakes. Springiness reflects the softness of steamed rice cake which in turn depends on the quantity and quality of the black gram used. The globulin and arabinogalactan components in black gram play a vital role in the steamed rice cake. Also as stated earlier, the polysaccharides present in basil seeds also owe to springiness of steamed rice cake.

Adhesiveness depends on the gelatinization and more fluidity of rice starch structure in the cooked samples³³. In this study the gelation property of basil seeds would have contributed to adhesiveness, stickiness, chewiness and gumminess of the steamed rice cakes. However, the textural attributes such as hardness, stickiness, cohesiveness and springiness are dependent on one another³⁴. Though, the variations were significantly different when compared with the control, it need not necessarily mean that the products are unacceptable. The entire TPA results signify that the textural parameters of Variations, V7 and V8 seem to be more acceptable, but cannot be concluded. Hence, all the variations were further subjected to organoleptic evaluation.

Table 3: Texture Profile Analysis of the Unprocessed, Roasted and Steamed Ocimum basilicum L. Seeds Incorporated Steamed Rice Cake

Each value in the table are represented as Mean ± SD (n=3). Statistically significant at p < 0.05, where ^a<b<c<d in each column. Different superscripts denote significant difference at (p<0.05).

The sensory scores of raw and processed (roasted and steamed) basil seeds incorporated steamed rice cakes are depicted in Table-4. According to the results presented, there is a significant difference between the appearance, colour, flavor, texture, taste, mouth feel and overall acceptability of the steamed O.basilicum seeds incorporated variations of the steamed rice cake, with respect to the processing techniques. The overall acceptability of the variations V9 to V12 was very less which is also slightly similar to the results depicted by TPA. Wherein, the overall acceptability of the raw or unprocessed O.basilicum seeds incorporated variations and roasted O.basilicum seeds incorporated variations of the steamed rice cake was maximum and the variations V4 and V8 show acceptance index parallel to the control. Although the TPA and the organoleptic evaluation indicate different results, as in certain parameters, (V7 was more competent to V8 than V4), the acceptability by human subjects will be of high significance. The literature has also stated that the TPA data need not be relevant substitutions for the sensory attributes always^35.

Table 4: Mean Organoleptic Analysis of the Unprocessed, Roasted and Steamed Ocimum basilicum L. Seeds Incorporated Steamed Rice Cake

Each value in the table are represented as Mean ± SD (n=3. Means with same superscript are not significantly different using Duncan’s Multiple Range Test (P < 0.05).

Conclusion

Steamed rice cakes being a versatile conventional product, the acceptability after value addition poses doubt. Hence prior to supplementation it was proposed to subject the developed twelve variations of steamed rice cake to different analytical procedures to test its nutritional, textural and sensory properties. It can be concluded from the results that the nutritional parameters were better in variation 8 and the organoleptic analysis has projected an overall acceptability of Variation 8 in which 20% of the roasted basil seeds were incorporated. Hence, considering the nutritional profile, textural analysis outcomes and the overall acceptability steamed rice cake with 20% of roasted basil seeds incorporation can be considered optimal for further studies, which will prove beneficial to persons who should be devoid of proteins from pulses for example, as in case of gout and other renal diseases. Further being a source of protein, minerals and fibre and can be recommended for diabetics, subjects with cardiovascular disorder and gastrointestinal disorders. With these inferences, the accepted variation (V8) will be subjected to supplementation in future studies and the constructive reports will be stated accordingly.

Acknowledgement

Nil

Funding Sources

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Conflict of Interest

The authors declare no conflict of interest.

 References

1. Naghibi F, Mosaddegh M, Mohammadi Motamed S, Ghorbani A. Labiatae family in folk medicine in Iran: from ethnobotany to pharmacology. Iranian J Pharm Res 2005; 2:63–79.
2. Munir, M., A. Qayyum, S. Raza, N.R. Siddiqui, A. Mumtaz, N. Safdar, S. Shible, S. Afzal and S. Bashir. Nutritional assessment of basil seed and its utilization in development of value added beverage. Pakistan Journal of Agricultural Research, 2017; 30(3): 266-271.
   CrossRef.
3. Anudurga Gajendiran, Vidhya Thangaraman, Suji Thangamani, Dhatchayani Ravi and Jayanthi Abraham. Antimicrobial, antioxidant and anticancer screening Of Ocimum basilicum Bulletin of Pharmaceutical Research. 2016;6(3):114-19
   CrossRef.
4. Renuagarwal, E.R. Rati, S.V.N. Vijayendra, M.C.Varadaraj, M.S. Prasad and Krishna Nand. Flavour profile of Idli batter prepared from defined microbial starter cultures. World Journal of Microbiology and Biotechnology. 2000; 16(7):687-690.
   CrossRef.
5. Elizabeth Yorke. Future of Idlis: A Scientific assessment. Dept. of Culinary Arts, Manipal University, Karnataka, 2014; 15-17.
6. Ivana Mezeyova, Alzbeta Hegedusova et al. Basil seeds as a source of antioxidants affected by fortification with selenium.Folia Horticulturae.2020;  32(1):11–20
   CrossRef.
7. Hosseini-Parvar SH, Mortazavi SA, Razavi SMA, Matia-Merino L, Goh KKT. Steady shear flow behavior of gum extracted from basil seed gum (Ocimumbasilicum L.): Effect of concentration and temperature. J Food Eng. 2010; 101:236–243.
   CrossRef.
8. P, Shalini. S. Standardization and Quality Evaluation of Idli Prepared from Pearl Milllet (Pennisetum glaucum). International Journal of Current Research. 2010; (5): 84-87.
9. Jenkins DJA, Wolever TMS, Jenkins AL. Starchy foods, and glycemic index. Diabetes Care. 1988; 11:149–59.
   CrossRef
10. Ghosh, Debasree, and Parimal Chattopadhyay. Preparation of Idli batter, its properties and nutritional improvement during fermentation. Journal of Food Science and Technology. 2011; 48(5): 610-51. Doi: 10.1007/s13197-010-0148-4.
    CrossRef
11. Nagarjuna VD, Manohar B. Rheology and particle size changes during Idli fermentation. J Food Eng. 2000; 43:167–171. doi: 10.1016/S0260-8774(99)00146-6.
    CrossRef
12. Samateh, Malick, Pottackal, N., Manafirasi et al. Unravelling the secret of seed-based gels in water: the nanoscale 3D network formation. Scientific reports. 2018; 8(1): 7315. doi: 10.1038/s41598-018-25691-3.
    CrossRef
13. Desikachar HSR, Radhakrishnamurthy R, Rao GR, Kadol SB, Srinivasan M, Subramanyan V. Studies on Idli fermentation. Part I. Some accompanying changes in the batter. J Sci Ind Res (India). 1962; 19C:168–172.
14. Manual of Methods of Analysis of Foods. Cereal and Cereal Products. Food Safety and Standards of India. Ministry of Health and Family Welfare. Govt.of India.2016.
15. FAO Food and Nutrition Paper 77, Food Energy – Methods of Analysis and Conversion Factors. Report of a Technical Workshop. Rome.2002; 3-6.
16. https://www.agriexpo.online/prod/perten-instruments/product-169961-65980.html
17. Kora, A.J. Applications of sand roasting and baking in the preparation of traditional Indian snacks: nutritional and antioxidant status. Bull Natl Res Cent. 2019; 43(158):1-11 https://doi.org/10.1186/s42269-019-0199-2
    CrossRef
18. Hussain N, Ishak I et al. Water Soluble Hydrocolloid from Basil Seed (Ocimum basilicum) Mucilage. Malaysian Applied Biology. 2019; 49 (2): 97-101.
19. A Shakerardekani, R Karim, HM Ghazali, NL Chin. Effect of roasting conditions on hardness, Moisture Content and Colour of Pistachio Kernels. International Food Research Journal. 2011; 18:704–710.
    CrossRef
20. Seyed M.A. Razavi. Emerging Natural Hydrocolloids: Rheology and Functions. John Wiley & Sons, 2019; 500-502.
    CrossRef
21. Batool SA, Rauf N, Tahir SS, Kalsoom R. Microbial and physico-chemical contamination in the wheat flour of the twin cities of Pakistan. Int J Food Saf. 2012; 14:75–82.
22. Uche Samuel Ndidi, Charity Unekwuojo Ndidi, Abbas Olagunju, Aliyu Muhammad, Francis Graham Billy, Oche Okpe, “Proximate, Antinutrients and Mineral Composition of Raw and Processed (Boiled and Roasted) Sphenostylis stenocarpaSeeds from Southern Kaduna, Northwest Nigeria”, International Scholarly Research Notices,  2014; 1-9.
    CrossRef
23. D. Olawepo O.T. Banjo, W.A. Jimoh et al. Effect of Cooking and Roasting on Nutritional and Anti-Nutritional Factors in Kenaf (Hibiscus Cannabinus L.) Seed Meal. Food Science and Quality Management. 2014;24.
24. Ntuli V, Mekibib SB, Molebatsi N, Makotoko M, Chatanga P, Asita OA. Microbial and physicochemical characterization of maize and wheat four from a milling company, Lesotho. Int J Food Saf. 2013; 15: 9-11.
25. AA Mariod, SY Ahmed et al. Effects of roasting and boiling on the chemical composition, amino acids and oil stability of safflower seeds. Journal of Food Science and Technology.2012; 47(8):1737-1743.
    CrossRef
26. Haripriya and Aparna NV. Effect of roasting on selected nutrient profile and functional properties of chia seeds (Salvia hispanica) and optimization of chia seed based instant soup mix. International Journal of Food Science and Nutrition. 2018; 3(2): 200-206.
27. Cherian, R. P. Health benefits of basil seeds. International Journal of Scientific Research in Science, Engineering and Technology.2019; 6(2):511–515
    CrossRef
28. Ayyappan Appukuttan Aachary, Duraiswamy Gobinath etal. Short chain xylooligosaccharides: a potential prebiotic used to improve batter fermentation and its effect on the quality attributes of Idli, a cereal–legume‐based Indian traditional food. International Journal of Food Science and Technology. 2011; 46(7): 1346-55
    CrossRef
29. S. R. Foods Consumed with Rice that Elicit a Reduction in Glucose Response among Healthy Individuals. Curr Res Nutr Food Sci 2020; 8(2).
30. Durgadevi and Shetty. Effect of ingredients on sensory profile of Idli. J Food Sci Technol.2014; 51(9):1773-83.
    CrossRef
31. Delikanli, B and Ozcan, T. Improving the textural properties of yogurt fortified with milk proteins. Journal of Food Processing and Preservation. 2017; 41(5).
    CrossRef
32. Jo Baker-Perrett, https://www.campdenbri.co.uk/, 2019.
33. Esmat Ghasemi, T.Hamed Mosavian etal. Effect of Stewing in Cooking Step on Textural and Morphological Properties of Cooked Rice. Rice Science. 2009; 16(3):243-46.
    CrossRef
34. Coralie Blanchard. On the study of the different factors influencing the structure and the texture of semi-humid baked aerated cereal products: sensory and instrumental dimensions of texture. Other. Université de Bourgogne.2014.
35. AK Thybo, M Martens. Instrumental and Sensory Characterization of Cooked Potato Structure. Journal of Texture Studies. 2007; 30(3): 259-278.
    CrossRef