Simultaneous extraction and fractionation of pufa from tropical tuna (thunnus tongol) head using pressure swing technique of supercritical CO2 (SC-CO2)

Tuna fishes are known as one of the main commodity of fisheries which is generally marketed as canned food or as loins/steaks. Tuna head is about 25% of body weight and discarded as processing leftover during canning process. The objective of this study was to use this fish waste (head) as a source of fish oil especially PUFA. Simultaneous extraction and fractionation of PUFA from tuna head were conducted using pressure swing technique of SC-CO2. The dry and grinded sample was pressurised with pure CO2 and then soaked in the vessel for 1 hrs, and extracted continuously for 20 min at optimal conditions of 35 MPa, 65 oC, 3 ml min-1. The pressurization-soaking-extraction treatment was denoted as “pressure swing method” in this study. The total fish oil (13.11 g/100 g wt.) from head was extracted in 7 successive pressurization-soaking-extraction steps and the yield of each step was defined as fractional yield. Fatty acid constituents of each fractional yield were analyzed separately by gas chromatography. The short chain fatty acid constituents were found to be extracted mainly in the first 3 fractions and the next 4 fractions were predominant in MUFA and PUFA. Significant amount of DHA (26.83%) were extracted from fraction 4 followed by fraction 7. During the holding periods the liquid CO2 penetrated into the sample matrix and dissolved the readily soluble SFA portion of the oil which was eluted preferentially faster compared with either MUFA or PUFA. Therefore, multiple pressure swing steps could extract and fractionate the short chain fatty acid from relatively less soluble portions of long chain PUFA-rich sample matrix. However, PUFA-rich fraction extracted from tuna head may effectively serve as a source of EPA and DHA in food and pharmaceutical industries

Cellulosic nanocomposites from natural fibers for medical applications: a review

The nanocellulose and its composites have been covered in this chapter which is confirmed to be a very versatile material having the wide range of medical applications, including cardiovascular implants, scaffolds for tissue engineering, repair of articular cartilage, vascular grafts, urethral catheters, mammary prostheses, penile prostheses, adhesion barriers, and artificial skin. These implants were produced from bioresorbable and/or biodegradable materials. Nanocellulose, such as that produced other than microfibrillated cellulose and cellulose nanowhiskers, is also produced by the bacteria (bacterial cellulose, BC) which is also an emerging biomaterial with great potential as a biological implant, wound and burn dressing material, and scaffolds for tissue regeneration. Moreover, the nanostructure and morphological similarities with collagen make cellulose attractive for cell immobilization and cell support. This article describes current and future applications of cellulosic nanofibers in the biomedical field. Cellulose micro-/nanofibril as a reinforcing material for composites is becoming more and more attractive to researchers in composite science because of its potential lightweight and high strength. In the present article, we have reviewed the nanocellulosic fibers-based nanocomposites for medical applications. Processing methods, properties, and various applications of cellulosic composites are also discussed in this article. However, the separation of cellulose nanofibers along with the manufacture of cellulose nanocomposites is still challengeable. The aim of this chapter is to demonstrate the current state of development in the field of cellulose nanofibril-based nanocomposite research and application through examples

Supercritical carbon dioxide fractionation of palm kernel oil and formulation of cocoa butter replacers fat.

The extraction of dehulled ground palm kernel using supercritical carbon dioxide (SC-C02) as a solvent at temperatures of 40 and 80°C and pressures of 20.7,27.6, 34.5, 41.4 and 48.3 MPa was studied. Continuous extraction was fractionated into four fractions and each fraction was collected for every 10 minutes. Thus the total extraction process was performed for 40 minutes extraction time. Kajian ke atas pengekstrakan isirung sawit tanpa testa hancur menggunakan lampau genting karbon dioksida (LG-C02) sebagai pelarut pada suhu 40 dan 80°C dan tekanan 20.7, 26.7, 34.5, 41.4 dan 48.3 MPa. Pengekstrakan berterusan dipemeringkatkan kepada empat pemeringkat dan setiap pemeringkat dikumpul selarna 10 minit dengan jumlah proses pengekstrakan dibuat selama 40 minit masa pengekstrakan

Dual modification of starch via partial enzymatic hydrolysis in the granular state and subsequent hydroxypropylation.

The effect of enzymatic pretreatment on the degree of corn and mung bean starch derivatization by propylene oxide was investigated. The starch was enzymatically treated in the granular state with a mixture of fungal alpha-amylase and glucoamylase at 35 degrees C for 16 h and then chemically modified to produce enzyme-hydrolyzed-hydroxypropyl (HP) starch. Partial enzyme hydrolysis of starch in the granular state appeared to enhance the subsequent hydroxypropylation, as judged from the significant increase in the molar substitution. A variable degree of granule modification was obtained after enzyme hydrolysis, and one of the determinants of the modification degree appeared to be the presence of natural pores in the granules. Enzyme-hydrolyzed-HP starch exhibited significantly different functional properties compared to hydroxypropyl starch prepared from untreated (native) starch. It is evident that the dual modification of starch using this approach provides a range of functional properties that can be customized for specific applications

Hydrolysis of granular starch at sub-gelatinization temperature using a mixture of amylolytic enzymes.

Native granular starches (corn, cassava, mung bean, and sago) were hydrolyzed using a mixture of alpha-amylase and glucoamylase at 35 °C for 24 h. Hydrolyzed starches were analyzed for the degree of hydrolysis and for physicochemical and functional properties. Corn starch showed the highest degree of hydrolysis, as evidenced by the presence of distinct pores penetrating deep into the granules. Enzymatic erosion occurred mainly at the surface for cassava, whereas isolated porous structures were observed in hydrolyzed mung bean and sago starch. The amylose content was significantly lower in all starches except for sago starch. The powder X-ray diffraction of all starches showed no significant changes after hydrolysis, but hydrolyzed starches showed a more crystalline nature. The action of enzymes caused significant changes in some pasting properties and in the swelling/solubility of starches. Evidently, enzymes were able to hydrolyze granular starches to a variable degree at sub-gelatinization temperature, and produced a relatively high degree of conversion

Modification of a gas chromatography-mass spectrometry method for the determination of acrylamide in fried snacks

Acrylamide is a toxic and probably carcinogenic compound and also neurotoxin in humans and animals that is formed naturally in certain foodstuffs, especially those rich in carbohydrate, during heat processing or cooking at high temperatures. This study was carried out to develop and validate the determination of acrylamide in fried snacks using gas chromatography-mass spectrometry (GCMS). The developed method involved the extraction of acrylamide with water followed by a cleanup treatment using Oasis HLB and MCX solid-phase extraction cartridges, bromination using reduced amount of saturated bromine water (from 15 to 2.5 ml due to bromine vapour is harmful and inhalation may be fatal as a result of spasm, inflammation, edema of the larynx and bronchi, also causes respiratory tract irritation with possible burns), then dehydrobromination by adding sodium thiosulfate solution until the yellow color has disappeared and using triethylamine to convert 2,3-dibromopropionamide to 2-bromopropenamide. This derivative is less polar compared to the acrylamide and is therefore easily soluble in non–polar organic solvents like ethyl acetate and hexane. The limit of detection (LOD) and limit of quantitation (LOD) of the method were 5 and 15 µg kg-1, respectively, and the regression coefficient was 0.9997. The recoveries of acrylamide in banana fritter samples at low, medium and high concentrations of 100, 200 and 4000 µg kg-1, respectively, were in the range of 84 to 109%. The repeatability and reproducibility values of the method ranged to 3-10 and 0.6–6, 0.3–8 for different days and different operators, respectively

Effects of meat preheating and wrapping on the levels of polycyclic aromatic hydrocarbons in charcoal-grilled meat.

The contamination of polycyclic aromatic hydrocarbons PAHs by thermally treated high-protein foods, such as charcoal-grilled meat products, is due to the generation by direct pyrolysis of food nutrients and the direct deposition of PAHs from smoke produced through incomplete combustion of the thermal agents. This study investigated the effects on the PAH (BaP, BbFln and Fln) contents by using two different types of treatments, preheating (steam and microwave) and wrapping (aluminium and banana leaf) of the meat samples prior to charcoal grilling. PAHs were extracted through tandem solid-phase extraction. The results showed that the applied preheating and wrapping treatments on the samples strongly affect the PAHs levels in the charcoal-grilled meat. No carcinogenic PAHs (BaP and BbFln) were detected in the samples after steam and microwave preheating or aluminium wrapping treatments. Significant reductions of Fln content, of up to 46% and 81% in beef and chicken samples, respectively, were observed in the study

Determination of acrylamide in banana based snacks by gas chromatography-mass spectrometry

Fried and baked banana-based snacks are popular in South East Asia and banana chip is popular in other countries, such as India, Indonesia, China, African countries, etc; these snacks may contain acrylamide in concentration which may be of concern due to its toxicity. This study was carried out to determine acrylamide concentration in popular banana based snacks in Malaysia using a modified method of gas chromatographymass spectrometry. The limit of detection and limit of quantitation of the modified method are 5 and 15 μg/kg, respectively. Acrylamide concentration of five types of Malaysian popular fried and baked banana based snacks from different local markets ranged from 74.0 to 7468.8 μg/ kg for banana fritter (pisang goreng), 28.9 to 243.7 μg/kg for banana chips (kerepek pisang), 160.7 to 500.4 μg/kg for sweet banana chips (kerepek pisang manis), not detected to 154.4 μg/kg for banana cake (kek pisang) and 31.7 to 609.1 μg/kg for banana balls (cekodok pisang). Analysis of variance showed a significant difference (P<0.05) in acrylamide concentration between different food types. From the estimate of banana fritter consumption data, the highest exposure to acrylamide in Malaysia is 1.2 μg/kg body weights