182 JOURNAL OF COSMETIC SCIENCE PROTEIN LOSS IN ug/g OF HAIR 200 COCONUT OIL MINERAL OIL SUNFLOWER OIL TYPES OF OILS [] NORMAL WITHOUT [] BLEACHED WITHOUT [] NORMAL WITH [] BLEACHED WITH Figure 5. Comparison of protein loss from normal and bleached hair in a salon trial. and then weighed. In the next step, the dry weight of the hair was determined by drying the tress in a vacuum oven at 50øC for 90 min, and then weighing it again. The percentage water retention index (WRI) is given by: WRI -- (Wwe t - Wary ) 100/Wary Half-head tests, Each half-head test involved 20 clients each with normal and bleached hair. The hair was parted in the middle and half the head was treated with the respective oil (3 ml approx.) and massaged thoroughly, while the other half was left without treatment. The oil was left on the hair for approximately 8 hr. Then the hair was washed with warm water (28øC, 200 ppm hardness) using 20% SLES, and rinsed well to remove any residue. To avoid inherent differences in damage from left to right side, the appli- cation of the treatment was randomized. Panelists with odd numbers were treated on the left side, while those with even numbers were treated on the right side. After shampooing and rinsing, the hair was combed with a fine-tooth comb (separate

EFFECT OF COCONUT OIL ON HAIR DAMAGE 183 Table III Pair-Wise Comparison Data for Treatment Effects for Protein Loss (t-values at 95% confidence level) Treatment Straight Wavy Curly Permed without MO (MO as post-wash) 0.452 -- 0.106 -- without CNO (CNO as 1.779 -- -- without SFO (SFO as post-wash) -- -- -- 0.461 without MO (MO as pre-wash) -- 0.431 -- 0.103 without CNO (CNO as 1.814 -- -- without SFO (SFO as pre-wash) -- -- 0.515 -- water--with and without MO 0.507 1.312 -- water--with and without CNO -- -- 1.762 water--with and without SFO -- 1.108 -- -- water--with and without MO -- 0.484 -- 0.354 water--with and without CNO 1.738 -- water--with and without SFO Undamaged--with and Undamaged--with and post-wash) Undamaged--with and Undamaged--with and Undamaged--with and pre-wash) Undamaged--with and Treatment with boiling (MO as post-wash) Treatment with boiling (CNO as post-wash) Treatment with boiling (SFO as post-wash) Treatment with boiling (MO as pre-wash) Treatment with boiling (CNO as pre-wash) Treatment with boiling (SFO as pre-wash) Treatment with bleaching agent--with and without MO (MO as post-wash) Treatment with bleaching agent--with and without CNO (CNO as post-wash) Treatment with bleaching agent--with and without SFO (SFO as post-wash) Treatment with bleaching agent--with and without MO (MO as pre-wash) Treatment with bleaching agent--with and without CNO (CNO as pre-wash) Treatment with bleaching agent--with and without SFO (SFO as pre-wash) Exposure to UV light--with and without MO (MO as post-wash) Exposure to UV light--with and without CNO (CNO as post-wash) Exposure to UV light--with and without SFO (SFO as post-wash) Exposure to UV light--with and without MO (MO as pre-wash) Exposure to UV light--with and without CNO (CNO as pre-wash) Exposure to UV light--with and without SFO (SFO as pre-wash) 1.565 0.139 1.588 0.345 0.684 0.210 0.345 0.265 0.092 0.583 2.012 0.098 1.850 1.728 0.407 1.780 0.087 t theoretical for 48 degrees of freedom at 95% confidence level = 1.645. comb for each side). After each of the ten combing strokes, both the hair and the comb were dipped in 200 ml of distilled water to recover broken cuticle debris. A total of 100 strokes (50 on each side) were applied. The suspension with cuticle debris was used for protein estimation. Analytical controls were run in the form of determination of the