Quality Characteristics of Crisp Biscuits Made from Xinyang Maojian Tea Residue by Its Different Additions

This study investigated the preparation of crisp biscuits by adding powdered Xinyang Maojian tea residue to wheat flour. The effects of Xinyang Maojian tea residue on the dynamic rheological properties of the dough were studied. The effect of adding 0%, 1%, 2%, 3%, 4%, and 5% tea residue on the texture property and sensory evaluation of the biscuits was explored. Scanning electron microscopy (SEM) was used to observe the microstructure of the biscuits, and Angiotool software was employed for analysis. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were used to compare the structural changes in the biscuits. The results showed that as the amount of Xinyang Maojian tea residue increased, the G' and G" values of the dough increased, indicating that the structure of the dough became progressively more compact. The hardness, brittleness, and chewiness of the biscuits increased, and the porosity also gradually increased. However, when the addition amount reached 2%, further increases in tea residue caused the structure of the biscuits to become looser, resulting in a decrease in hardness, brittleness, and chewiness, as well as a reduction in porosity. The biscuits with 2% Xinyang Maojian tea residue had a softer internal structure and the largest porosity, which might be one of the reasons for their better taste. Sensory evaluation showed that the biscuits with a 2% addition received the highest score. XRD and FTIR analysis indicated that the addition of tea residue caused changes in the crystalline structure of the starch. Although it did not alter the functional group structure of low gluten powder, the addition of Xinyang Maojian tea residue led to a reduction in the intensity ratio of the peaks (1047/1022 cm⁻¹) and (1022/995 cm⁻¹) in the resulting crisp biscuits.