Assessment of fatty acid composition and response surface optimization of ultrasonic-assisted extraction of phenolic compounds from Pouteria campechiana pulp

Pouteria campechiana (PC) pulp was analyzed for its fatty acid composition. Fourteen different kinds of fatty acids were found with the major fatty acids viz. palmitic acid (C16:0), oleic acid (C18:1), myristic acid (C14:0) and linolenic acid (C18:2), making up approximately 73.8 % of the total fatty acid content (TPC). An ultrasonic-assisted extraction (UAE) of the polyphenolic bioactive components in PC pulp powder were statistically optimized using the Central Composite Design (CCD). Factors that gave maximized TPC in the crude extract of PC pulp powder were assessed for factors, ratio of ethanol:water, extraction temperature and extraction time. The established optimum conditions of the CCD model with R2 = 0.8833 were within the studied range and agreed well with the predicted values. Under an optimized condition [30 min, 35 °C and ratio of ethanol:water, 60:40 (%, v/v)], the highest TPC was 1162.80 mg GAE/100 g in comparison to the predicted 1115.06 mg GAE/100 g. High Performance Liquid Chromatography confirmed that gallic acid and its derivatives were the major components, comprising a ?0.03 % (w/w) of the PC pulp crude extract. Pertinently, a high recovery value in the HPLC validation data (109.84 %, R2 = 0.9995) suggests the method was accurate

Pouteria campechiana pulp ethanol-water extract as a bioactive ingredient for topical delivery of oil-in-water nanoemulsion

The aging process is an inevitable natural course of each human, affecting the entire body, notably the skin's surface. Numerous over-the-counter nanoformulations are available, but none has considered Pouteria campechiana (Pc) extract as a source of the active ingredient in the formulation. In this study, the hydrophilic fraction of the Pc fruit extract was used as an O/W formula for topical application to the human skin. Fatty acid analysis showed that over 18 types of fatty acids were present in the Pc pulp, with the Pc oil showing an acid value of 6.451. The proximate analysis gave an 8.4% moisture content, 1.7% ash, 4.0% protein, 1.0% fat, 84.9% carbohydrates, with a total energy value of 364.60 Kcal/100g. Next, ultrasonic-assisted extraction (UAE) used in this study facilitated satisfactory extraction of phenolic compounds from the Pc pulp. Under optimized UAE conditions (extraction time = 30 min, extraction temperature = 25 °C, ratio of ethanol:water = 60%, v/v), the experimental response surface methodology-assisted optimization, a maximum total phenolic content (TPC) of 1162.80 mg GAE/100 g (DW) was obtained. In the screening process, compositions of jojoba oil (JO), grapeseed oil (GSO), Tween 80, and glycerol (GLY) at 6–12%, 20–26%, 5–7%, and 25–27% gave good particle sizes and PdI between 280–420 nm and 0.18–0.44, respectively. The resultant Pc extract showed a percentage 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition at 82.91%, IC50 of 2.344 mg/mL, ferric reducing antioxidant power (FRAP) value of 836.30±30.60 μmol/100 g DW, and total flavonoid content (TFC) of 813.29 mg QE/100 g. In the D-optimal Mixture Experimental Design experiment, the optimized Pouteria campechiana extract nanoemulsion (OPT-PcE-Ne) formulation comprised JO amount (6.25%), GSO amount (34.38%), T80 (14.06%), and GLY (45.31%) at fixed 0.5% phenoxyethanol, 5% PcE, 2% xanthan gum (XG), and 0.5% perfume oil. The OPT-PcE-Ne yielded the lowest particle size at 222±0.61 nm and PdI of 0.16. The OPT-PcE-Ne gave good organoleptic and stability profiles by remaining creamy white, without any color change for up to 90 days, with a zeta potential of –32.6±0.5 mV and an acceptable pH (4.81±0.02). The OPT-PcE-Ne droplets were averagely sized at 93.46−183.13 nm in the transmission electron microscopy (TEM) micrograph and gave conductivity of 0.22 μS/cm. The OPT-PcE-Ne rheology followed a Bingham plastic behavior, suggesting that the cream must be applied to the skin in successive layers. In the accelerated tests, phase separation in the OPT-PcE-Ne was absent in the ultracentrifugation and freeze-thaw cycle studies. Next, samples stored for 6 weeks showed mean particle size and PdI between 155–315 nm and 0.16−0.28 for 4±2 °C, 415–150 nm and 0.16−0.26 for 28±2 °C and 125–295 nm and 0.14−0.45 for storage at 50±2 °C. The general non-linearity for the OPT-PcE-Ne stored at 4±2 °C, 28±2 °C proved the system was not destabilized by coalescence but more so by Ostwald ripening when stored for long durations at 28±2 °C (R2=0.7753). The OPT-PcE-Ne exhibited a release of ~0.18% of PcE in the 0–6 h duration, with a maximal level of 5.17% after 24 h. Pertinently, the OPT-PcE-Ne was also free from microorganisms- and heavy metal contamination. In the sensory evaluation study, the OPT-PcE-Ne exhibited the highest color and texture scores compared to other commercial lotions scoring 7.3 and 6.6, respectively. However, the scent was the lowest-rated factor at a collective scale of 6.1. The study findings supported the use of the PcE as a natural-based ingredient in cosmeceuticals and the OPT-PcE-Ne as a topical lotion on human skin

An overview of nanoemulsion: concepts of development and cosmeceutical applications

The interest in nanoscale emulsions has considerably grown in recent decades as a consequence of their specific attributes such as high stability, attractive appearance, in addition to high performance and sensorial advantage. In fact, it nanoemulsions are one of the major popular formulation systems in the pharmaceutical and cosmeceutical fields. The thermodynamic and high kinetic stability, besides the minute droplet size of nanoemulsions have spurred their rapid development as a system for delivery of bioactive substances/drugs in cosmetics and dermatological formulations. The composition and the technique of preparation very much define the quality of nanoemulsions. They are mainly targeted at high performance, product distribution to consumers, alongside the prospects of mass production. Formulators, however, do face certain limitations especially regarding the diffusion of active ingredients into the human skin. This review describes the popular techniques used by formulators in recent years to prepare nanoemulsions as final application products for cosmeceutical application. Correspondingly, an overview of characterisation technologies to differentiate between the micro and nanoemulsions - alongside their benchmarks in terms of their physical and thermodynamic stabilities, is also described in this review

An overview of technologies for immobilization of enzymes and surface analysis techniques for immobilized enzymes

The current demands of sustainable green methodologies have increased the use of enzymatic technology in industrial processes. Employment of enzyme as biocatalysts offers the benefits of mild reaction conditions, biodegradability and catalytic efficiency. The harsh conditions of industrial processes, however, increase propensity of enzyme destabilization, shortening their industrial lifespan. Consequently, the technology of enzyme immobilization provides an effective means to circumvent these concerns by enhancing enzyme catalytic properties and also simplify downstream processing and improve operational stability. There are several techniques used to immobilize the enzymes onto supports which range from reversible physical adsorption and ionic linkages, to the irreversible stable covalent bonds. Such techniques produce immobilized enzymes of varying stability due to changes in the surface microenvironment and degree of multipoint attachment. Hence, it is mandatory to obtain information about the structure of the enzyme protein following interaction with the support surface as well as interactions of the enzymes with other proteins. Characterization technologies at the nanoscale level to study enzymes immobilized on surfaces are crucial to obtain valuable qualitative and quantitative information, including morphological visualization of the immobilized enzymes. These technologies are pertinent to assess efficacy of an immobilization technique and development of future enzyme immobilization strategies

Candida rugosa lipase immobilized onto acid-functionalized multi-walled carbon nanotubes for sustainable production of methyl oleate

The chemical production of methyl oleate using chemically synthesized fatty acid alcohols and other toxic chemicals may lead to significant environmental hazards to mankind. Being a highly valuable fatty acid replacement raw material in oleochemical industry, the mass production of methyl oleate via environmentally favorable processes is of concern. In this context, an alternative technique utilizing Candida rugosa lipase (CRL) physically adsorbed on multi-walled carbon nanotubes (MWCNTs) has been suggested. In this study, the acid-functionalized MWCNTs prepared using a mixture of HNO3 and H2SO4 (1:3 v/v) was used as support for immobilizing CRL onto MWCNTs (CRL–MWCNTs) as biocatalysts. Enzymatic esterification was performed and the efficiency of CRL–MWCNTs was evaluated against the free CRL under varying conditions, viz. temperature, molar ratio of acid/alcohol, solvent log P, and enzyme loading. The CRL–MWCNTs resulted in 30–110 % improvement in the production of methyl oleate over the free CRL. The CRL–MWCNTs attained its highest yield (84.17 %) at 50 °C, molar ratio of acid/alcohol of 1:3, 3 mg/mL of enzyme loading, and iso-octane (log P 4.5) as solvent. Consequently, physical adsorption of CRL onto acid-functionalized MWCNTs has improved the activity and stability of CRL and hence provides an environmentally friendly means for the production of methyl oleate

Sustainable production of the emulsifier methyl oleate by Candida rugosa lipase nanoconjugates

Acid functionalization of multi-walled carbon nanotubes (F-MWCNTs) using a mixture of HNO3 and H2SO4 (1:3, v:v) was used as support materials for the adsorption of Candida rugosa lipase (CRL) as nanoconjugates (CRL-MWCNTs) for producing methyl oleate. To evaluate the competency of the CRL-MWCNTs nanoconjugates, parameters viz. reaction time, surfactant as well as thermostability and reusability were investigated. The characterization of CRL-MWCNTs nanoconjugates using Fourier transform infrared spectroscopy, Field Scanning Electron Microscopy and Transmission Electron Microscopy revealed successful attachment of CRL onto the F-MWCNTs. Utilization of CRL-MWCNTs nanoconjugates resulted in a higher acid conversion in the synthesis of methyl oleate (79.85% at 11 h of reaction time) when compared with the free CRL i.e. an approximately 1.5-fold improvement over the free CRL. The highest percentage of esterification (83.62%) was observed following the use of nonionic surfactant when compared with the anionic and cationic ones. The CRL-MWCNTs nanoconjugates could be used up to 5 cycles, retaining 50% of its residual activity. Since the preparation of the CRL-MWCNTs nanoconjugates was facile and cheap while producing reasonable yield, the CRL-MWCNTs nanoconjugates developed here were found as promising biocatalysts for the production of methyl oleate

Statistical modelling of eugenol benzoate synthesis using rhizomucor miehei lipase reinforced nanobioconjugates

The chemical route for synthesizing eugenol benzoate is concomitant with a myriad of environmentally unfavorable practices viz. the use toxic chemicals, tedious separation process and emancipation of harmful unwanted by-products. In this perspective, an alternative technique utilizing Rhizomucor miehei lipase (RML) immobilized onto activated chitosan-multiwalled carbon nanotubes (RML/CS/MWCNTs) is proposed. The properties and morphology of the RML/CS/MWCNTs were characterized using field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The approach of response surface methodology employing the central composite design (CCD) based on four parameters (incubation time, temperature, substrate molar ratio, and enzyme loading) were used to optimize the experimental conditions for the RML/CS/MWCNTs catalyzed synthesis of eugenol benzoate. The study found that the high yield production of eugenol benzoate is greatly affected by factors such as temperature and incubation time. Under optimized conditions, the highest yield of eugenol benzoate was obtained (56.13%) at 60 °C, 6 h of incubation time, enzyme loading (15 mg) and molar ratio of eugenol/benzoic acid of 4:1. Therefore, the RML/CS/MWCNTs developed here appear to be a promising alternative yet environmentally friendly biocatalyst for a sustainable production of eugenol benzoate