Development and Characterization of Tamarind Sauce Supplemented With Moringa Leaf Powder

INTRODUCTION

Fruits and vegetables are essential because they provide minerals, dietary fiber, and necessary vitamins to the whole population of the world. Despite having limited calories, fruits and vegetables are vital for the development and proper working of the human body (Ibe et al., 2020). The main components in fruits and vegetables are phenolic compounds and antioxidants, which provide health-promoting benefits and lower the risk of several diseases like cancer (Coman et al., 2020). The World Health Organization (WHO) recommends a daily intake of at least 400g of fruits and vegetables per person (Ibe et al., 2020).

Globally, over 2 billion people suffer from malnutrition, with the highest prevalence rates in Africa and South Asia (Kukreti et al., 2023). Half of the global population, mainly from Africa and Asia, face nutrition deficiency owing to their sole reliance on cereals (Vinoth and Ravindhran, 2017). Despite self-sufficiency in food, 60% population in Pakistan is food insecure. The majority (one-third) of the children in developing countries, including Pakistan, are malnourished (Sultan and Iram, 2023). Consumption of a balanced diet from different food groups with diet diversification and supplementation is one of the options to combat malnutrition. The supplementation is the addition of various nutrients to foods in order to improve the micronutrient status, making fortified products readily available and affordable for people to avoid widespread nutrient shortages and associated deficiencies (Saeed et al., 2021).

Moringa (Moringa oleifera L.) is an Indian herbal plant grown in tropical and subtropical regions. It is referred to as the miracle tree due to its variety of health-promoting attributes like anticancer, antidiabetic, anti-inflammatory, hypocholesterolemic, cardioprotective, antihypertensive, hepatoprotective, antibacterial, and antioxidant characteristics. It is effective to treat skin problems and for weight reduction. Additionally, it aids in boosting blood antioxidant levels, lowering blood sugar, and reducing chronic inflammation (Islam et al., 2021). The traditional use of moringa leaves, seeds, immature seed pods, bark, roots, sap, and flowers in medicine is widespread.

Moringa leaf powder (MLP) is a promising option for fortification to formulate various functional foods as it is enriched with vitamins, minerals, proteins, dietary fiber and phytochemicals including tannins, alkaloids, polyphenols, flavonoids, carotenoids and tocopherols that can have potential health benefits (Ariani et al., 2023). MLP is used as a nutritional supplement for children, infants, and pregnant women in regions with food scarcity to prevent protein-energy malnutrition. MLP contains 27.4% protein, 5.6% oil, and 23.7% dietary fiber, which makes it a potential food supplement. It contains potassium 15 times higher than bananas, 10 times greater vitamin-A than carrots, 7 times more vitamin C than oranges, 17 times more calcium than milk, and 25 times greater iron than spinach (Rockwood et al., 2013).

Tamarind (Tamarindus indica L.) is a tropical fruit and a member of the Leguminosae family, originating from Africa. Its pulp contains a higher quantity of carbohydrate, fiber, protein, calcium, iron, phosphorus, vitamin B2, and C (Abdi and Serrem, 2013). Tamarind pulp is used as a snack and an imperative ingredient in the preparation of various culinary dishes, sauces, curries, chutneys, pulp powder, tamarind juice concentrate, candy, jam, syrup, seasoning, and flavoring. Sauce is a semi-solid or liquid food used to relish foods; to enhance nutritional value, appeal, richness, and moistness, and to garnish foods (Ozolina et al., 2019). Keeping in view the therapeutic and nutritional benefits of tamarind and moringa leaf powder, MLP-supplemented tamarind sauce was developed to improve the nutritional profile, and its sensory attributes were evaluated.

MATERIALS AND METHODS

2.1 Procurement of raw materials

This study was conducted at the Fruit and Vegetable Laboratory, National Institute of Food Science and Technology, University of Agriculture, Faisalabad, Pakistan. Fresh moringa leaves were collected from the University of Agriculture, Faisalabad, whereas tamarind and the remaining raw materials required for sauce preparation were purchased from the local market of Faisalabad.

2.2 Preparation of moringa leaf powder

Fresh moringa leaves were de-stemmed and washed thoroughly with water to remove adhering dirt and foreign matter. The cleaned leaves were dipped in 1% saline solution to reduce surface microbial load and then rinsed with distilled water. For color retention, the leaves were treated with 0.1% potassium metabisulfite solution for 15 min. Thereafter, the solution was drained, and the leaves were shade-dried on aluminum trays, followed by dehydration at 75 °C until the moisture content reached 6–8%. The dried leaves were ground to obtain a fine powder, which was used for product development.

2.3 Preparation of tamarind pulp and moringa leaf powder supplemented tamarind sauce

Dehydrated tamarind was cleaned and soaked in warm water for 15–20 min to soften the pulp. The seeds and outer skin were removed, and the pulp was strained through a fine-mesh sieve to obtain a smooth tamarind base. Tamarind sauce was then prepared by adding water to the pulp and cooking the mixture at 100°C for 30 min. Moringa leaf powder was incorporated according to the treatment plan by replacing tamarind pulp at 0, 1, 2, 3, 4, and 5%, corresponding to treatments T0, T1, T2, T3, T4, and T5, respectively. Red chili, black pepper, salt, and sugar were added according to the treatment plan, and the mixture was further cooked until the desired level of total soluble solids was achieved. Sodium benzoate was added at the end of cooking, and the sauce was removed from the heat. Vinegar was added immediately before filling. Plain tamarind sauce without moringa leaf powder served as the control. The prepared samples were stored under ambient conditions for 28 days and analyzed at 7-day intervals. All analyses were performed in triplicate.

2.4 Proximate analysis of MLP

The proximate composition of moringa leaf powder was determined using AOAC (2016) methods for moisture, ash, crude fat by Soxhlet, crude fiber, and crude protein by Kjeldahl’s method.

2.5 Color, TSS, acidity, pH, and ascorbic acid

Color and TSS of moringa leaf powder supplemented tamarind sauce were determined using a colorimeter and a digital refractometer, respectively. Acidity and pH were determined according to AOAC (2016), and ascorbic acid was determined according to Pavani et al. (2022).

2.6 Antioxidant activity and total phenolics

Sample extracts were prepared in methanol, sonicated, centrifuged, and the supernatant was used for antioxidant capacity measured as percent inhibition of DPPH free radical, whereas the Folin-Ciocalteu method was used to measure total phenolic contents.

2.7 Microbial analysis (Total Plate Count)

Total plate count of moringa leaf powder supplemented tamarind sauce was determined on nutrient agar after serial dilution and incubation at 37°C for 24 h. Results were expressed as log CFU/mL.

2.8 Sensory evaluation

Sensory evaluation of moringa leaf powder supplemented tamarind sauce was conducted at different storage intervals using a 9-point hedonic scale for color, taste, texture, and overall acceptability (Meilgard et al., 2016).

2.9 Statistical analysis

The experiment was conducted using a two-factor factorial arrangement under a completely randomized design (CRD). Data were statistically analyzed using Statistix 8.1 and Tukey’s HSD test at p ≤ 0.05.

RESULTS AND DISCUSSION

3.1 Proximate composition of moringa leaf powder

The means for proximate composition of moringa leaf powder revealed 7.4 ± 0.05% moisture, 25.4 ± 0.4% crude protein, 6.49 ± 0.03% crude fat, 9.82 ± 0.02% ash, 12.45 ± 0.03% crude fiber, and 38.94 ± 0.02% NFE. The change in proximate composition may be due to different varieties, environmental conditions, and processing techniques.

3.2.1 Total soluble solids (TSS)

Treatments, storage, and their interaction exerted a highly significant effect on TSS value of the MLP-supplemented tamarind sauce. TSS increased with an increase in storage time and levels of moringa leaf powder. The highest TSS was noted in T5 (44.88°B), while the lowest was in T0 (38.64°B). The TSS value increased significantly from 39.10°B at day zero to 43.85°B on the 28th day due to acid hydrolysis and breakdown of complex carbohydrates into sugars.

3.2.2 Titratable acidity

Treatments and storage intervals had a highly significant effect on titratable acidity. The highest mean titratable acidity among treatments was recorded in T0 (1.77%), whereas the lowest was observed in T5 (1.09%). In contrast, storage resulted in a gradual increase in acidity, with the lowest mean value at day 0 (1.21%) and the highest at day 28 (1.48%).

3.2.3 pH values

pH increased progressively with increasing concentration of moringa leaf powder. The highest pH was recorded in T5 (2.48), whereas the lowest was observed in T0 (2.11). During storage, however, pH decreased gradually, with the maximum mean pH at day 0 (2.41) and the minimum at day 28 (2.19).

3.2.4 Color of tamarind sauce

Food color is an important attribute appreciated by consumers and a main factor for product acceptance. L, a*, and b* values all declined with increasing concentration of moringa leaf powder and with storage duration, indicating reduced brightness, redness, and yellowness.

3.2.5 Antioxidant activity

The antioxidant activity of moringa leaf powder was 58.62% based on the inhibition percentage of DPPH free radicals. Mean values among treatments revealed that T5 (46.99%) exhibited the highest antioxidant activity, whereas the minimum was observed in T0 (39.28%). During storage, antioxidant activity decreased from 46.49% at day zero to 39.41% on the 28th day.

3.2.6 Total phenolic contents

Total phenolic content increased with the rise in concentration of moringa leaf powder in tamarind sauce. T5 showed the maximum value (119.41 mg/100g GAE), whereas the minimum value was observed in T0 (108.38 mg/100g GAE). During storage, TPC gradually reduced from 116.16 to 112.34 mg/100g GAE.

3.2.7 Ascorbic acid

T5 had the maximum ascorbic acid (40.91 mg/100 g), whereas T0 had the minimum (36.37 mg/100 g). Ascorbic acid declined slightly with storage from 39.02 mg/100 g at day zero to 38.92 mg/100 g on the 28th day.

3.2.8 Total plate count

Mean values revealed the highest total plate count in T0 (1.68 log CFU/ml) and the lowest in T5 (1.35 log CFU/ml). The mean comparison of storage indicated the lowest total plate count was 0.90 at zero days, which increased to the highest total plate count (2.14) after 28 days.

3.2.9 Sensory evaluation

Sensory quality is a key determinant of product acceptability. The highest mean score for sensorial color among treatments was observed in T0/T1, and among MLP-supplemented treatments T1 was considered the best and mostly preferred by the panelists. Taste, texture, and overall acceptability decreased progressively with increasing MLP concentration. Treatments with MLP up to 3% were acceptable, while T4 and T5 showed pronounced aftertaste.

CONCLUSION

Malnutrition or micronutrient deficiency is prevalent globally, and supplementation with vegetal sources like moringa leaf powder being rich in functional ingredients, is a promising option to counter it. Tamarind is a cheap product, easily available year-round, and delivers vitamins and minerals to meals in addition to its sour flavor. TSS, pH, ascorbic acid, total phenolics, and antioxidant activity of moringa-supplemented tamarind sauce showed a rising tendency with increasing levels of MLP addition. Acidity, total microbial count, and color (L, a*, and b*) showed an inverse relation with the addition of MLP. Sensory evaluation showed T1 obtained the best sensory perception scores, whereas T3 showed an improved nutritional profile. T4 and T5 showed pronounced aftertaste.

Competing interests

The authors declare that they have no competing interests.

Funding

No funding.

Author’s contribution

Sidra Bashir performed the methods, investigation, and writing of the original draft. Muhammad Atif Randhawa conceptualized and supervised the research work as well as proofread the manuscript. Zafar Iqbal helped in the conceptualization and investigation of the product. Hafiz Muhammad Jawad Saleem helped in writing this manuscript, applied statistical software, and proofread the manuscript.

Ethical statement

No animals were used or harmed, and the study did not involve clinical or invasive human experimentation.

REFERENCES