In food and beverages, it is being processed into ready-to-drink juices and juice concentrates to use as refreshing drinks. The juice is primarily valued for making acid beverages. Some people use its extract as an ingredient to some delicacies and some sauces. Some of them boil the sliced fruits with cranberries to make a start sauce. In the Philippines, the extracted juice, with the addition of gum tragacanth as an emulsifier, is pasteurized and bottled commercially. This product must be stored at low temperature to keep well. Pectin can also be recovered from the peel as a by-product of juice production.

In addition, a study conducted by Dr. Lee Seong Wei and his team from the Department of Fisheries and Aquaculture of the University of Malaysia on the antimicrobial properties of tropical plants against 12 pathogenic bacteria isolated from aquatic organisms. In their study, 9 tropical plants including calamansi were used in the test for antimicrobial activity. It was found out that all the 9 plants tested showed antimicrobial activity against one or more species of the 12 bacteria tested. The 12 bacteria strains used were Vibrio aglinolyticus, Vibrio parahaemolyticus, Vibrio harveyi, Vibrio vulnificus, Vibrio cholera, E. coli, Citrobacter freundii, Edwardsiella tarda, aeromonas hydrophilla, Salmonella, sp., Schewanella putrifaciens, and Streptococcus sp. It was also found out that Taro, Calamansi, Gotu Kola, and Morinda were the most active antimicrobial plants [Lee,, 2008]. Another study conducted by him on the antimicrobial property of 2-hydroxypropane-1,2,3-tricarboxylic acid isolated from Calamansi Extract. It was found out in his study that the crude extract and its bioactive component might have potential as antimicrobial agent for aquaculture use [Lee, 2009].

As for its pharmaceutical use, the Calamansi extract is taken orally as a cough remedy and anti-inflammation. When slightly diluted and drunk warm, it serves as a laxative. Combined with pepper, it is prescribed in Malaya to expel phlegm. The root enters into a treatment given at childbirth. The distilled oil of the leaves can induce the expulsion of gas from the stomach with more potency than peppermint oil. The fruits may be crushed with the saponaceous bark of Entada Phaseoloides Merr for shampooing the hair, or the fruit juice applied to the scalp after shampooing. It eliminates itching and promotes hair growth. Rubbing calamansi juice on insect bites banishes the itching and irritation. It bleaches freckles and helps to clear up acne vulgaris and pruritus vulvae. It may also serve as a body deodorant.

Moreover, a study was conducted by Che Rugayah from the Department of Pharmacology in the Universiti Sains Malaysia on the Antianxiety and Antidepressive Effects of Essential Oils of Citrus Spp in Mice. Their study provides some evidences to indicate that the smelling of essential oils (0.1 mL) of calamansi confer anti-anxiety effect. They have concluded in their study that essentials oils of the Citrus family may affect behavior. However, the mechanism of actions of these essential oils is not known. Further studies will be needed to explore in the possible mechanism of action. These will require neurological test and related test to ascertain the effects observed in their study [Rugayah, 2011].

A study was also conducted in the year 2010 by the Chemistry Analytical and Research Laboratory of the Ateneo de Davao University on the Comparison of the Nutritive Values of Calamansi (Citrofortunella microcarpa), Lemon (Citrus limon) and Orange (Citrus sinensis) Juices. In their study, the amounts of sugar, sodium, calcium, magnesium, phosphorus, iron, zinc, and ascorbic acid in the three juices were determined. The results of their analysis are shown in table 1.

Table 1. Results of the determination of sugar, sodium, calcium, magnesium, phosphorus, iron, zinc, and ascorbic acid of Calamansi, Lemon, and Orange juices.

Calamansi Nutrition
As seen from the Table 1, Calamansi juice was found to have the highest amounts of essential nutrients namely calcium, iron, magnesium, sodium, and zinc, as well as a lower amount of ascorbic acid and sugar compared to lemon and orange juices [Tan, 2010].

In cosmetics and households, it is used as a whitening agent and a grease remover [Morton,1987]. The juice is used to remove or bleach ink stains in fabrics. The essential oil can also be employed as scenting agent in lotions, detergents, soaps, perfumes, and colognes.