No abstract

Virgin coconut oil (VCO) has been gaining popularity in recent times. During its production, byproducts such as coconut skim milk and insoluble protein are obtained which are underutilized or thrown away to the environment at present. This study deals with utilization of these byproducts to obtain a value-added product, namely, coconut protein powder. When coconut milk was subjected to centrifugation, three phases, namely, fat phase (coconut cream), aqueous phase (coconut skim milk), and solid phase (insoluble protein) were obtained. The coconut skim milk and insoluble protein were mixed and homogenized before spray drying to obtain a dehydrated protein powder. The proximate analysis of the powder showed high protein content (33 % w/w) and low fat content (3 % w/w). Protein solubility was studied as a function of pH and ionic content of solvent. Functional properties such as water hydration capacity, fat absorption capacity, emulsifying properties, wettability, and dispersibility of coconut protein powder were evaluated along with morphological characterization, polyphenol content, and color analysis. Coconut protein powder has shown to have good emulsifying properties and hence has potential to find applications in emulsified foods. Sensory analysis showed high overall quality of the product, indicating that coconut protein powder could be a useful food ingredient.

The coconut residual fiber (CRF) is the major byproduct obtained during production of virgin coconut oil. Its application as a biosorbent for adsorption of Congo red was investigated. The CRF was subjected to different pretreatments, namely, pressure cooking, hexane treatment, acid treatment and their combinations. The pretreatment of CRF with the combination of hexane, acid, and pressure cooking resulted in the highest degree of adsorption. The equilibrium data were analyzed and found to fit best to both Langmuir and Freundlich isotherms. Thermodynamic parameters such as standard free energy (ΔG kJ mol), standard enthalpy (ΔH, kJ mol) and standard entropy (ΔS, kJ mol K) of the systems were calculated by using the Langmuir constant. The ΔG, ΔH and ΔS were found to be 16.51 kJ mol, -19.39 kJ mol and -0.12 kJ mol K, respectively, at 300 K. These thermodynamic parameters suggest the present adsorption process to be non-spontaneous and exothermic. The adsorption process was observed to follow pseudo-second-order kinetics. The results suggest that CRF has potential to be a biosorbent for the removal of hazardous material (Congo red dye) with a maximum adsorption capacity of 128.94 mg g at 300 K.

Coconut, a tropical fruit, is a well-known source of drink, food and oil as well. Numerous unprocessed, semiprocessed and processed coconut products have entered the global markets in small and big quantities. In the coconut industry, downstream processing plays vital role as the different products obtained are a result of different unit operations such as extraction, concentration and drying. Products like copra, coconut oil and desiccated coconut have a growing demand along with stringent quality specifications when exported to non-producing countries. These demands can be met only by large scale production using advanced technologies in drying and/or expelling under hygienic conditions and improvised packaging. Value added products such as nata-de-coco, coconut vinegar, toddy, etc. are being produced using microorganisms for bioconversion using coconut as a raw material. Aqueous processing and enzymatic treatment can favor the extraction of coconut oil in environmentally safe and economical manner, also yielding an edible protein product. Diversification of coconut derived products and value addition could only help the coconut growers in getting remunerative returns for the produce. This article aims to review coconut processing and related issues with special emphasis on bioprocessing and bioprocess engineering which have revolutionised the scale at which value added coconut products can be manufactured.