Effect of orange juice added in different concentrations on bioactive properties, phenolic components, fatty acid composition and sensory properties of tahini halva

The moisture contents of tahini halva samples fortified with different concentrations of 10%, 20%, and 30% orange juice ranged between 1.41% in the tahini halva with 30% orange juice addition and 2.41% in the tahini halva with 10% orange juice addition. The lowest and highest fat contents of the halva samples were determined in the tahini halva with 30% orange juice addition (28.70%) and the plain tahini halva (30.60%), respectively. The total phenolic content of halvahs ranged between 0.36–0.68 mg GAE/100g, and the highest value was found in the tahini halva made with 10% orange juice addition (0.68 mg GAE/100g). The flavonoid content of the control and halva samples produced with 10%, 20%, and 30% orange juice concentrations was found to be 4.43, 14.43, 8.71, and 5.00 mg QE/100g, respectively, and a decreasing trend was observed as the concentration of orange juice increased. The antioxidant activity values of the halva samples ranged between 0.12–0.30 mmol/kg, and the highest value was determined in the tahini halva prepared with 10% orange juice addition (0.30 mmol/kg). Kaempferol was the dominant constituent of halva samples (0.57–172.98 mg/100g), followed by gallic acid (16.13–74.70 mg/100g), catechin (0.50–21.24 mg/100g), and rutin (0.28–4.96 mg/100g) in decreasing order. The gallic acid, caffeic acid, and kaempferol contents of tahini halva increased up to the sample with 20% orange juice addition, and then decreased. In halva fats, linoleic acid was the most abundant component and ranged between 42.00% and 44.10%, followed by oleic, palmitic, and stearic acids, respectively. In color analysis, L* value (lightness) ranged between 62.35–89.08, while a* (redness) and b* (yellowness) values decreased. Phosphorus, magnesium, potassium, and calcium contents of tahini halva were determined to be between 2925.58–3131.91 ppm, 1103.89–1586.06 ppm, 1305.85–1367.98 ppm, and 841.32–1051.20 ppm, respectively. The amounts of iron, zinc, copper, manganese, boron, aluminum, and other minerals also varied depending on the addition of orange juice. In terms of taste, odor, color, texture, and sandiness, the plain tahini halva received the highest appreciation score. The overall acceptability score was determined as 4.57 for the plain tahini halva, while it was 3.57 for the tahini halva prepared with 10% orange juice addition. The results obtained show that the addition of orange juice is effective on the composition and functional properties of tahini halva, but a decrease was observed in some parameters as the concentration increased.