American Journal of Plant Sciences, 2013, 4, 1941-1948 http://dx.doi.org/10.4236/ajps.2013.410240 Published Online October 2013 (http://www.scirp.org/journal/ajps) 1941 Chemical Analysis of Carica papaya L. Crude Latex Jeana S. Macalood * , Helen J. Vicente, Renato D. Boniao, Jessie G. Gorospe, Elnor C. Roa Mindanao State University at Naawan, Naawan, Misamis Oriental, Philippines. Email: * jmacalood@yahoo.com Received July 11 th , 2013; revised August 11 th , 2013; accepted September 15 th , 2013 Copyright © 2013 Jeana S. Macalood et al. This is an open access article distributed under the Creative Commons Attribution Li- cense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Crude latex of Carica papaya L. has been known to offer a lot of benefits and potentials especially in the agricultural industry and human health. This study focuses on the latex coming from its fruits of Papaya CX variety. Seven to eight longitudinal incisions were made in order to allow latex to appear and drain in the collecting devices. 439.5 g dried la- tex was stored in plastic containers and freezed. Results showed that dried latex contained higher amount of crude pro- tein (57.24 ± 0.69%), followed by moisture (17.76 ± 0.09%), ash (7.00 ± 0.01%), crude fat (5.21 ± 0.13%) and crude fiber (0.67 ± 0.09%) based on the complete proximate analysis. In the enzyme analysis, papain had protease activity of 2655 units·g −1 at pH 5.5 and 285 units·g −1 at pH 9.0. These results provided evidence that papain as a protease enzyme is found in the crude latex of papaya which is a major constituent in various proteolytic activities. Crude latex from C. papaya L. can be utilized to address the issues in agricultural farms to accelerate production and reduce environmental hazards. Keywords: Carica papaya; Papaya CX Variety; Latex; Protease Activity; Papain; Complete Proximate Analysis 1. Introduction Latex-bearing plants are believed to provide protection against the attack of herbivores. Latex is known to com- pose of various kinds of proteins including enzymes which interact with the cellular aspect of the host insects resulting in growth inhibition, physiological damages and mortality. This prompted much research endeavour aim- ing to provide exact information on the defense mecha- nisms offered by the constituting compounds among lateces. Many of these compounds provide resistance to herbivores via toxicity or antinutritive effects, whereas others are involved in the stickiness that can mire insect herbivores [1]. These defense-related components appear- ing in latex of distant phylogenetic groups are thought to have possible biological effects on herbivores. Among these compounds are the proteases which have shown toxicological effects on insects. Proteases from a variety of sources (viruses, bacteria, fungi, plants, and insects) have toxicity towards insects [2]. Some of these insecti- cidal proteases evolved as venom components, herbivore resistance factors, or microbial pathogenicity factors, while other proteases play roles in insect development or digestion, but exert an insecticidal effect when over-ex- pressed from genetically engineered plants or microbial pathogens. Many of these proteases are cysteine proteases, al- though insect-toxic metalloproteases and serine proteases have also been examined [2]. Cysteine proteases are re- ported from latex of plant families such as Caricaceae, Moraceae and Apocynaceae [3,4]. In addition, some la- tex proteins are confined to specific plant taxa and have been suggested to be involved in plant defense. These compounds include phosphatase in Euphorbiaceae [5]; lipase in Caricaceae, Euphorbiaceae, Apocynaceae [6-8]; and glutaminyl cyclase in Caricaceae (papaya) [9,10]. Ca- rica papaya Linn. being a monoecious, dioecious or her- maphrodite tree is the most common species of the fam- ily Caricaceae [11,12]. Carica papaya preparations can be efficiently used in tissue burn and microbial/helmintic in- fection. It can be also used as insecticidal/molluscicidal activity against various pests [13]. This plant contains specialized cells (laticifers) dispersed throughout most plant tissues that secrete “latex” [14]. Papaya latex is a thixotropic fluid with a milky appearance that contains about 85% water. An insoluble particulate fraction whose composition is still practically unknown, makes up 25% of the dry matter. The soluble fraction, however, contains both the usual ingredients such as carbohydrates (~10%), salts (~10%) and lipids (~5%), and representative biomo- lecules such as glutathione, cysteine proteinases (~30%) * Corresponding author. Copyright © 2013 SciRes. AJPS