This lap trial was conducted in the research & development laboratory of Yemeni company for industry & trade, Taiz (2007/ 2008) to study effect of six levels of Al- haidwan flour (0, 0.4, 0.8, 1.2, 1.6 and 2%) and tow levels of ascorbic acid (0 and 40 ppm) on quality of three sorts of biscuit/cookie (Tops, Abu-Walad and Al-belad) produced in Yemen. All levels of al-haidwan were used to study its effect on chemical and rheological properties of biscuit dough, while only the first four levels, were used accompanied with ascorbic acid, for biscuits quality investigation, Results showed an increase of water absorption, mixing time and development time with the increase of al- haidwan levels (except 0.4% level). Dough stability was not affected by al- haidwan. Extensibility decreased with al-haidwan increase, but resistance to extensibility and number ratio, were increased. Spread ratio of biscuit decreased at lower level of al-haidwan, compared to control, and increased at higher levels. There was a significant reaction between al-haidwan and ascorbic acid addition, but ascorbic acid didn't affect spread ratio. Al-haidwan levels significantly affected biscuit diameter, but not ascorbic acid, where reaction between these factors was observed. Biscuit defects were decreased by increasing al-haidwan levels. Sorts of biscuits were significantly different in defect percent. Reaction between sorts of biscuit and al-haidwan addition showed a significant affect, but not ascorbic acid. Sensory evaluation had showed showed a sginificant affect of al- haidwan, ascorbic acid, biscuits and within reaction.

Key Words :Biscuit/cookie, haidwan, spread ratio, defects.