Change in firmness is one of the main indicators in judging qual-ity of fruit and is closely affected by ripening. Reduction in fruit texture can occur via two possible mechanisms of action. The first mechanism is due to the breakdown of polymeric carbohydrates that happens during ripening and which cause weakening of the cell walls. Though at the initial stages, the texture makes the fruit more palatable, the plant structures will eventually disintegrate and this will lead to fruit softening (Wills et al., 2007). Carrageenan, being a polysaccharide, provides a good barrier against oxygen and other non-polar substances (Lacroix and Tien, 2005). Appli-cation of carrageenan as a surface coating for papaya was expected to reduce oxygen permeability and thus reduce respiration rate. This would subsequently delay ripening and possibly the hydrolysis activities that can cause fruit softening. This phenomenon was indi-rectly shown by the positive linear coefficient value of carrageenan (+11.1070) with firmness, which indicates that firmness of papaya fruit was better when carrageenan concentrations increased.