Introduction Fruits such as mangoes, pineapples, berries and papaya have diversified tastes and flavours and make excellent sources of various minerals and vitamins in the diet (Rababah, Ereifej, & Howard 2005, p. 4445). Among the numerous antioxidants found in fruits, vitamin C has the most significant biological role in the human body. Vitamin C helps to decrease levels of C-reactive protein (CRP) and to fight inflammations. In addition, vitamin C is a predictor of heart disease, threat of arteriosclerosis, as well as, various forms of cancer. L-Ascorbic acid is both an anti-oxidant and free radical scavenger. It is found in various citrus fruits and leafy vegetables (Brevard, Marques, Renfroe, Lee, & Gloeckner 2010, p. 760). Vitamin C is necessary for human growth and repair of tissues, tendons, ligaments and blood vessels through the formation of collagen. The ease with which vitamin C oxidizes causes it to diminish faster in fresh fruits than in processed ones, when cooked or stored in the open air (Vasco C, Ruales J, & A 2008, p. 817). Ascorbic acid is freely soluble in water, which means tinned fruits retain their vitamin C in the liquid. Vitamin C is slightly acidic and is partly soluble in alcohol, and insoluble in Chloroform, ether and benzene (Rickman, Barrett, & Bruhn 2007). The formula for ascorbic acid is C 6 H 8 O 6 . Its structural formula is shown in figure 1 below: Figure 1: structural formula for ascorbic acid (Rickman, Barrett, & Bruhn 2007). Lack of vitamin C causes Scurvy, which is characterized by weakness and small hemorrhages all over the body that cause the skin and gums to bleed, as well as loosening of teeth. Since human beings cannot store vitamin C in the body, it should be replenished on a daily basis, with a minimum requirement of 30 mg (Connell, Zoellner, Yadrick, Chekuri, Crook, & Bogle 2011). Over 80% of vitamin C in the human diet is obtained from fruits and vegetables. However, fruits face rapid deterioration after cropping due to their high moisture content. As a result, fruits undergo various processing activities in order to reduce their moisture content, which also reduces microbiological activity. Reducing water activity improves the stability of fruits by reducing both physical and chemical reactions that occur during storage (Miller & Knudson 2012, p. 14). Research suggests that heat treatment of fresh fruits during processing causes a significant loss on vitamin C; however, canning preserves the remaining nutrients level over a long time relative to fresh produce (Rickman, Barrett and Bruhn 2007, p. 936). The amount of vitamin C in fresh products begins to reduce immediately after harvest. Research suggests that the level of vitamin C loss depends on crop variety, as well as, grower processes that have a direct impact on vitamin C content (Koyuncy & Dilmacunal 2010, p. 96). A variety of techniques can be used to determine vitamin C in fruits (Koyuncy & Dilmacunal 2010, p. 97). This experiment employs the new calorimetric technique that uses Folin phenol reagent to compare vitamin C content in fresh and processed pineapples and strawberries. Project Aims and Objectives Aims   * To determine the vitamin C (ascorbic acid) content of fresh, frozen and tinned (canned) pineapples and strawberries using new calorimetric technique that uses Folin phenol reagent.   * To compare vitamin C content in fresh, frozen an