Development and quality evaluation of Spirulina (Arthrospira platensis)-fortified peanut chikki as a protein-rich functional snack

Introduction

The increasing prevalence of lifestyle-related health concerns and micronutrient deficiencies has intensified the demand for foods that provide adequate nutrients along with biologically active components. In recent years, functional foods have received considerable attention because they can combine nutritional value with naturally occurring bioactive compounds. This has encouraged researchers to explore nutrient-dense ingredients for the development of convenient, acceptable, and value-added food products. Among the ingredients of increasing interest, spirulina has gained attention because of its high protein content and diverse range of bioactive constituents (Becker, 2007; Gohara-Beirigo et al., 2022) [1,2] . Arthrospira platensis, commonly known as spirulina, is a filamentous, photosynthetic cyanobacterium that has been widely investigated as a nutrient-rich food ingredient. Its dried biomass is characterized by a high protein content, generally reported in the range of approximately 55-70%, along with essential amino acids, minerals, vitamins, essential fatty acids, pigments, and other bioactive compounds (Habib et al., 2008; Becker, 2007) [3,1] . Spirulina is particularly recognized for its phycocyanin, chlorophyll, carotenoids, phenolic compounds, and other antioxidant constituents. These components contribute to its nutritional and functional potential and make spirulina a promising ingredient for nutritional enrichment of conventional food products (Karkos et al., 2011; Fernandes et al., 2023) [5,4] . The nutritional importance of spirulina extends beyond its protein content. Phycocyanin is one of the characteristic pigments of spirulina and has been extensively studied because of its antioxidant and other biological properties. Carotenoids, chlorophyll, phenolic compounds, and flavonoids may also contribute to the antioxidant potential of spirulina. Consequently, incorporation of spirulina into food products may improve their nutritional density and provide additional bioactive components (Fernandes et al., 2023; Gohara-Beirigo et al., 2022) [4,2] . However, the characteristic blue-green color and distinctive flavour of spirulina can influence the sensory properties and consumer acceptability of food products. Therefore, optimization of the incorporation level is essential to achieve a balance between nutritional enhancement and sensory quality.

Peanut (Arachis hypogaea L.) is an important oilseed legume widely consumed as a food ingredient and is valued for its protein, fat, energy, minerals, and characteristic sensory properties. Its high energy density, pleasant flavour, crunchy texture, and broad consumer acceptance make it suitable for the preparation of traditional and valueadded snack products. Peanut also provides a complementary protein and energy source that can be combined with spirulina to develop nutritionally enriched foods. The successful incorporation of proteinrich ingredients into peanut-based traditional products has previously been investigated, demonstrating the potential of peanut as a suitable food matrix for nutritional enhancement (Pallavi et al., 2014) [6] . Jaggery is a traditional non-centrifugal sugar commonly used in Indian food preparations and traditional confectionery products. It functions primarily as a sweetening and binding ingredient and contributes to the characteristic color, flavor, and texture of products such as chikki. Unlike refined sugar, jaggery retains certain mineral constituents and naturally occurring components derived from sugarcane juice (Jaffé, 2015) [7] . The combination of peanut and jaggery therefore provides a familiar and widely accepted traditional food matrix suitable for incorporation of nutritionally valuable ingredients. Chikki is a traditional Indian confectionery product generally prepared using peanuts and jaggery. It is valued for its characteristic crisp texture, pleasant taste, convenience, and energy density. Conventional peanut chikki provides protein and energy; however, its nutritional quality can potentially be enhanced through the incorporation of nutrient-dense functional ingredients. Previous research has demonstrated the feasibility of nutritional enrichment of peanut chikki with protein, mineral, and vitamin sources (Pallavi et al., 2014) [6] . Incorporating spirulina into peanut chikki may therefore provide an opportunity to combine the nutritional advantages of spirulina with the desirable sensory characteristics and consumer familiarity of traditional peanut chikki. The combination of spirulina, peanut, and jaggery provides complementary nutritional and technological characteristics. Spirulina contributes concentrated protein and bioactive compounds, peanut contributes protein, fat, energy, and desirable sensory properties, while jaggery acts primarily as a sweetening and binding agent. However, increasing the level of spirulina may alter the color, flavor, taste, and texture of the final product. Thus, sensory evaluation is an important step in determining an appropriate level of spirulina incorporation that provides nutritional enrichment without compromising product acceptability. Spirulina has been investigated for incorporation into several food applications, including beverages, bakery products, pasta, snacks, and other value-added foods. The growing interest in microalgae-based food products is associated with their potential contribution of pro-teins, pigments, minerals, and other bioactive compounds (Gohara-Beirigo et al., 2022) [2] . However, comparatively limited attention has been given to the incorporation of spirulina into traditional Indian confectionery products such as peanut chikki. In addition, optimization of the spirulina incorporation level based on sensory acceptability and subsequent evaluation of the nutritional characteristics of the selected product remain important areas for product development. The present study was undertaken to develop and standardize spirulina-enriched peanut chikki using different levels of Arthrospira platensis powder. The developed formulations were evaluated for sensory acceptability to identify the most acceptable level of spirulina incorporation. The selected formulation was further evaluated for its proximate composition and other nutritional and functional characteristics, including phytochemicals, phytopigments, and essential amino acid composition. The study aimed to assess the potential of spirulina as a value-added ingredient for improving the nutritional quality of traditional peanut chikki while maintaining desirable sensory acceptability.

Materials and Methods

Materials

The present investigation was carried out during the academic year 2025-2026 at the Department of Food Chemistry and Nutrition, College of Food Technology, Vasantrao Naik Marathwada Krishi Vidyapeeth (VNMKV), Parbhani, Maharashtra, India, in collaboration with the Department of Food Process Technology, Department of Food Microbiology and Safety, and Department of Food Engineering, College of Food Technology, and Department of Soil Science, College of Agriculture. Spirulina powder (Arthrospira platensis) was procured from the local market of Parbhani. Peanuts, jaggery, liquid glucose and cardamom were procured locally. Analytical-grade chemicals and reagents were used for chemical and instrumental analyses. LDPE, HDPE and PET packaging materials were used for storage studies.

Formulation and preparation of spirulina peanut chikki

Preliminary trials were conducted to standardize the level of spirulina powder incorporation in peanut chikki. Five formulations were prepared, namely T 0 (control), T 1 , T 2 , T 3 and T 4 . The control formulation (T 0 ) was prepared without spirulina powder, while T 1 , T 2 , T 3 and T 4 contained 2, 4, 6 and 8 g of spirulina powder, respectively, per 100 g of peanut. The quantity of jaggery was gradually reduced from 170 g in the control to 162 g in T₄ to obtain an appropriate consistency and taste. Liquid glucose was incorporated to improve the binding, texture and consistency of the chikki, while cardamom powder was added for flavor enhancement.

Methodology for preparation of spirulina peanut chikki

Sensory evaluation

Sensory evaluation of the developed spirulina peanut chikki was conducted using a 9-point hedonic scale as described by Amerine et al.

(1965) [8] . Ten semi-trained judges evaluated the samples for appearance and color, flavor, taste, texture and overall acceptability. The samples were coded and presented to the judges under similar conditions. The judges independently evaluated each sample using the following hedonic scale: 9 = like extremely, 8 = like very much, 7 = like moderately, 6 = like slightly, 5 = neither like nor dislike, 4 = dislike slightly, 3 = dislike moderately, 2 = dislike very much and 1 = dislike extremely. The scores obtained from the ten judges were averaged for each sensory attribute and treatment. The treatment receiving the highest overall acceptability score was considered the most acceptable formulation and was selected for further quality evaluation.

Proximate analysis

The proximate composition of spirulina powder and spirulina peanut chikki was determined using standard AOAC methods. Moisture was estimated by hot air oven drying at 105 ± 1 °C, ash by muffle furnace incineration at 550-600 °C, protein by the Kjeldahl method using a conversion factor of 6.25, fat by soxhlet extraction using petroleum ether, and crude fibre by acid-alkali digestion. Carbohydrate content was calculated by difference. All analyses were carried out in triplicate and expressed as percentage of the sample (AOAC, 1984; AOAC, 2000) [9] .

Phytochemical and phytopigment analysis

The phytochemical constituents of spirulina powder were evaluated for total phenolic content, total flavonoid content and tannin content. Total phenolic content was determined by the Folin-Ciocalteu method using gallic acid as standard, total flavonoids by the aluminium chloride colorimetric method using quercetin as standard, and tannins by the Folin-Denis method using tannic acid as standard. The results were expressed as mg GAE/g, mg QE/g and mg TAE/100 g, respectively (Singleton et al., 1965) [10] . Phytopigments including chlorophyll, phycocyanin, total carotenoids and β-carotene were determined by spectrophotometric and chromatographic methods. Chlorophyll was extracted with 90% acetone and measured at 630, 647 and 664 nm (Jeffrey et al., 1975) [11] . Phycocyanin was estimated spectrophotometrically at 620 nm following phosphate-buffer extraction. Total carotenoids were determined at 450 nm, while β-carotene was quantified by reverse-phase HPLC at 450 nm.

Amino acid profile

The amino acid profile of spirulina powder was determined by HPLC following acid hydrolysis, derivatization and chromatographic separation. Tryptophan was analysed separately using alkaline hydrolysis. Essential amino acids including isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, histidine and valine were identified by comparison with authentic standards and quantified using calibration curves. Results were expressed as g/100 g sample on a dry-weight basis (AOAC, 1984).

Color analysis

Color characteristics of spirulina powder and spirulina peanut chikki were measured using a Hunter color difference meter.

Statistical analysis

All experiments were conducted in triplicate. The data were statistically analysed using a Completely Randomized Design (CRD) and ANOVA. Significant differences among treatments were determined at the 5% level of significance (P < 0.05). Standard error (SE) and critical difference (CD) were calculated wherever applicable, following Panse et al. (1967) [12] . Sensory evaluation of the spirulina peanut chikki samples was carried out using a 9-point hedonic scale as described by Maynard A. Amerine et al. (1965) [8] . Ten semi-trained judges evaluated the samples for appearance and color, flavor, taste, texture and overall acceptability. The sensory scores ranged from 9 (like extremely) to 1 (dislike extremely). Each treatment was evaluated under identical conditions, and the mean scores obtained for each sensory attribute were used for statistical analysis.

Result and Discussion

Sensory evaluation of spirulina peanut chikki

Among the five formulations, T 3 (6 g spirulina powder/100 g peanut) recorded the highest scores for appearance and color (8.5), flavor (8.3), taste (8.3), texture (8.5) and overall acceptability (8.4). The control (T 0 ) also showed good acceptability, with an overall acceptability score of 8.0. The incorporation of spirulina at 2 and 4 g levels (T 1 and T 2 ) resulted in comparatively lower sensory scores. However, T 4 (8 g spirulina) received the lowest scores, particularly for appearance and color (7.0) and taste (7.0), indicating that higher incorporation of spirulina negatively affected the sensory characteristics of chikki. Therefore, T 3 was selected as the most acceptable formulation for further quality evaluation.

Phytonutrients and phytopigments composition of spirulina powder

Table 3. Phytonutrients and Phytopigments composition of spirulina powder

Phytonutrients and Phytopigments Value

Chlorophyll (%) 1.52 ± 0.03 β-Carotene (mg/100g) 6.4 ± 0.08 Phycocyanin (mg/g) 160 ± 0.28 Total carotenoids (mg/100g) 502 ± 0.72 Antioxidant activity (mg TE/g) 15.82 ± 0.32 Total phenolic content (mg GAE/g) 14.25 ± 0.35 Total flavonoid content (mg QE/g) 4.85 ± 0.14 Tannin content (mg TAE/g) 1.62 ± 0.05

Each value is average of three determinations

The spirulina powder showed appreciable levels of bioactive pigments and phytochemicals. Chlorophyll, β-carotene, phycocyanin and total carotenoids were found to be 1.52 ± 0.03%, 6.40 ± 0.08 mg/100 g, 160 ± 0.28 mg/g and 502 ± 0.72 mg/100 g, respectively. The antioxidant activity was 15.82 ± 0.32 mg TE/g, while total phenolic, flavonoid and tannin contents were 14.25 ± 0.35 mg GAE/g, 4.85 ± 0.14 mg QE/g and 1.62 ± 0.05 mg TAE/g, respectively. The appreciable pigment content, particularly phycocyanin and carotenoids, indicates the potential of spirulina as a source of natural bioactive compounds. Similar studies have reported that phycocyanin, carotenoids and chlorophyll contribute significantly to the antioxidant potential of Spirulina, while phenolic and flavonoid compounds may also contribute to its antioxidant activity. The data presented in Table 4 revealed that incorporation of spirulina powder improved the nutritional composition of peanut chikki. The moisture content increased from 2.26 ± 0.08% (T 0 ) to 3.16 ± 0.09% (T 3 ), while fat content increased from 23.06 ± 0.22% to 23.80 ± 0.24%. The protein content showed a marked increase from 14.23 ± 0.19% (T 0 ) to 18.23 ± 0.21% (T 3 ). Similarly, ash content increased from 1.90 ± 0.05% to 2.46 ± 0.06%, and crude fibre increased from 2.20 ± 0.07% to 3.16 ± 0.08%. In contrast, carbohydrate content decreased from 56.76 ± 0.31% (T 0 ) to 49.23 ± 0.28% (T 3 ). The increase in protein, ash and fibre can be attributed to the nutrient-rich composition of spirulina, which is recognized as a valuable source of protein, minerals and dietary components. Similar nutritional improvements have been reported in spirulina fortified food products (Becker, 2007; Khanra et al., 2018) [1,13] . The amino acid composition of the sample is presented in Table 5.

Chemical composition of spirulina peanut chikki

Essential amino acids composition of spirulina powder

The results of the present study revealed variation in the concentration of the analysed amino acids. Phenylalanine showed the highest concentration (8.48 ± 0.07 g/100 g), followed by leucine (7.65 ± 0.06 g/100 g), valine (5.45 ± 0.05 g/100 g), isoleucine (5.40 ± 0.05 g/100 g), and threonine (5.20 ± 0.05 g/100 g). Lysine, methionine, and histidine were recorded at 4.42 ± 0.04, 2.12 ± 0.02, and 1.54 ± 0.02 g/100 g, respectively, while tryptophan showed the lowest concentration (1.02 ± 0.01 g/100 g). The relatively higher levels of leucine, isoleucine, and valine indicate a good contribution of branched-chain amino acids (BCAAs) to the amino acid profile. Overall, the present study demonstrated a diverse essential amino acid composition, indicating the potential nutritional value of the sample. Essential amino acid composition is considered an important parameter for evaluating the nutritional quality of dietary proteins (WHO et al., 2007) [14] .

Conclusion

The present study demonstrated the potential of Arthrospira platensis (spirulina) powder as a nutritionally enriching ingredient in traditional peanut chikki. Spirulina powder exhibited a high protein content along with appreciable levels of phycocyanin, carotenoids, phenolic compounds, flavonoids, tannins and antioxidant activity, indicating its nutritional and functional potential. Incorporation of spirulina at different levels influenced the sensory characteristics of peanut chikki, with the 6% incorporation level (T 3 ) showing the highest sensory scores for appearance and color, flavor, taste, texture and overall acceptability. The selected T 3 formulation also demonstrated improved protein, ash and crude fibre contents compared with the control, while carbohydrate content was comparatively reduced. The amino acid profile of spirulina further indicated the presence of several essential amino acids, particularly phenylalanine, leucine, valine, isoleucine and threonine. Overall, incorporation of spirulina at an optimized level of 6 g per 100 g peanut resulted in a nutritionally enhanced chikki with good sensory acceptability. The developed spirulina-en riched peanut chikki may therefore serve as a promising value-added, protein-enriched traditional snack. Further studies on shelf life, storage stability, bioavailability and consumer acceptance at a larger scale are recommended to establish its potential for commercial application.

Acknowledgement

AcknowledgementThe author sincerely expresses gratitude to the College of Food Technology, VNMKV, Parbhani, for providing the necessary facilities and support to carry out this research work successfully. The author is deeply thankful to the research guide, Dr. K. S. Gadhe, Department of Food Chemistry and Nutrition, for his valuable guidance, continuous encouragement, constructive suggestions, and support throughout the research work. The author also extends sincere thanks to the teaching and non-teaching staff of the department for their cooperation and assistance. Finally, the author is grateful to family members and friends for their constant support, encouragement, and cooperation during the course of this research project.

References

1. Becker EW. Micro-algae as a source of protein. Biotechnol Adv. 2007;25(2):207-210.
2. Gohara-Beirigo AK, Matsudo MC, Cezare-Gomes EA, de Carvalho JCM, Danesi EDG. Microalgae trends toward functional staple food incorporation: sustainable alternative for human health improvement. Trends Food Sci Technol. 2022;125:185199.
3. Habib MAB, Parvin M, Huntington TC, Hasan MR. A review on culture, production and use of Spirulina as food for humans and feeds for domestic animals and fish. FAO Fisheries and Aquaculture Circular No. 1034. Rome: Food and Agriculture Organization of the United Nations; 2008.
4. Fernandes R, Campos J, Serra M, Fidalgo J, Almeida H, Casas A, et al. Exploring the benefits of phycocyanin: from Spirulina cultivation to its widespread applications. Pharmaceuticals. 2023;16(4):592.
5. Karkos PD, Leong SC, Karkos CD, Sivaji N, Assimakopoulos DA. Spirulina in clinical practice: evidence-based human applications. Evid Based Complement Alternat Med. 2011;2011:531053.
6. Pallavi BV, Chetana R, Reddy SY. Processing, physico-chemical, sensory and nutritional evaluation of protein, mineral and vitamin enriched peanut chikki-an Indian traditional sweet. J Food Sci Technol. 2014;51(1):158-162.
7. Jaffé WR. Nutritional and functional components of non-centrifugal cane sugar: a compilation of the data from the analytical literature. J Food Compos Anal. 2015;43:194-202.
8. Amerine MA, Pangborn RM, Roessler EB. Principles of sensory evaluation of food. New York: Academic Press; 1965.
9. Association of Official Analytical Chemists. Official methods of analysis of AOAC International. 17th ed. Horwitz W, editor. Gaithersburg (MD): AOAC International; 2000.
10. Singleton VL, Rossi JA Jr. Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents. Am J Enol Vitic. 1965;16(3):144-158.
11. Jeffrey SW, Humphrey GF. New spectrophotometric equations for determining chlorophylls a, b, c1 and c2 in higher plants, algae and natural phytoplankton. Biochem Physiol Pflanz. 1975;167(2):191-194.
12. Panse VG, Sukhatme PV. Statistical methods for agricultural workers. 2nd ed. New Delhi: Indian Council of Agricultural Research; 1967.
13. Khanra S, Mondal M, Halder G, Tiwari ON, Gayen K, Bhowmick TK. Downstream processing of microalgae for pigments, protein and carbohydrate in industrial application: a review. Food Bioprod Process. 2018;110:60-84.
14. World Health Organization, Food and Agriculture Organization of the United Nations, United Nations University. Protein and amino acid requirements in human nutrition: report of a joint FAO/WHO/UNU expert consultation. WHO Technical Report Series No. 935. Geneva: World Health Organization; 2007.
15. Janda-Milczarek K, Szymczykowska K, Jakubczyk K, Kupnicka P, Skonieczna-Żydecka K, Pilarczyk B, et al. Spirulina supplements as a source of mineral nutrients in the daily diet. Appl Sci. 2023;13(2):1011.
16. Maddiboyina B, Vanamamalai HK, Roy H, Ramaiah S, Gandhi S, Kavisri M, et al. Food and drug industry applications of microalgae Spirulina platensis: a review. J Basic Microbiol. 2023;63(6):573-583.
17. Pathare PB, Opara UL, Al-Said FAJ. Colour measurement and analysis in fresh and processed foods: a review. Food Bioprocess Technol. 2013;6(1):36-60.
18. How to cite this article: Misal RV, Gadhe KS, Ghatge PU, Sadawarte S. Development and quality evaluation of Spirulina (Arthrospira platensis)-fortified peanut chikki as a protein-rich functional snack. International Journal of Advanced Biochemistry Research. 2026;SP-10(9):2496-2500. doi: https://w ww.doi.org/10.33545/26174693.2026.v10.i9Sae.10206