Presence of fat, oil, and grease (FOG) in wastewater is an ever-growing concern to municipalities and solid-waste facility operators. FOG enters the sewer system from restaurants, residences, and industrial food facilities. Its release into the sewer system results in a continuous build-up that causes eventual blockage of sewer pipes. Several researchers have investigated FOG deposition based on the local conditions of sewers and lifestyle. This paper attempts to review the physical and chemical characteristics of FOG, sources of FOG, and potential chemical and biological reactions of FOG. The effect of the aforementioned factors on the FOG-deposition mechanism is also discussed. Moreover, insight into the current control and treatment methods and potential reuse of FOG is highlighted. It is expected that this review would provide scientists and the concerned authorities a holistic view of the recent researches on FOG control, treatment, and reuse.

View full abstract

Carotenoids are bioactive compounds with remarkably special properties produced by plants in response to internal and external stresses. In this review paper, we focus on the subject of carotenoid biosynthesis and several factors that have been reported to significantly enhance or reduce carotenoid accumulation in studied plant species. These factors include varietal aspects, location, growing season, and type of stress experienced by a plant. In addition, we propose that there are three stress resistance mechanisms in plants: avoidance, tolerance, and acclimation. Better understanding of the environmental factors affecting carotenoid biosynthesis will help researchers to develop methods for enhancing the production of carotenoids and other pigments to desired concentrations in plant crops.

View full abstract

Carotenoids are antioxidants with pharmaceutical potential. The major carotenoids important to humans are α-carotene, β-carotene, lycopene, lutein, zeaxanthin, and β-cryptoxanthin. Some of the biological functions and actions of these individual carotenoids are quite similar to each other, whereas others are specific. Besides genotype and location, other environmental effects such as temperature, light, mineral uptake, and pH have been found affect carotenoid development in plant tissues and organs. Therefore, this research investigated the effects of the season and storage periods during postharvest handling on the accumulation of carotenoid in pumpkin. This study shows that long-term storage of pumpkins resulted in the accumulation of lutein and β-carotene with a slight decrease in zeaxanthin. The amounts of β-carotene ranged from 174.583±2.105 mg/100g to 692.871±22.019 mg/100g, lutein from 19.841±9.693 mg/100g to 59.481±1.645 mg/100g, and zeaxanthin from not detected to 2.709±0.118 mg/100g. The pumpkins were collected three times in a year; they differed in that zeaxanthin was present only in the first season, while the amounts of β-carotene and lutein were the highest in the second and third seasons, respectively. By identifying the key factors among the postharvest handling conditions that control specific carotenoid accumulations, a greater understanding of how to enhance the nutritional values of pumpkin and other crops will be gained. Postharvest storage conditions can markedly enhance and influence the levels of zeaxanthin, lutein, and β-carotene in pumpkin. This study describes how the magnitudes of these effects depend on the storage period and season.

View full abstract

In recent years, astaxanthin is claimed to have a 10 times higher antioxidant activity than that of other carotenoids such as lutein, zeaxanthin, canthaxanthin, and β-carotene; the antioxidant activity of astaxanthin is 100 times higher than that of α-tocopherol. Penaeus monodon (tiger shrimp) is the largest commercially available shrimp species and its waste is a rich source of carotenoids such as astaxanthin and its esters. The efficient and environment-friendly recovery of astaxanthins was accomplished by using a supercritical fluid extraction (SFE) technique. The effects of different co-solvents and their concentrations on the yield and composition of the extract were investigated. The following co-solvents were studied prior to the optimization of the SFE technique: ethanol, water, methanol, 50% (v/v) ethanol in water, 50% (v/v) methanol in water, 70% (v/v) ethanol in water, and 70% (v/v) methanol in water. The ethanol extract produced the highest carotenoid yield (84.02 ± 0.8 μg/g) dry weight (DW) with 97.1% recovery. The ethanol extract also produced the highest amount of the extracted astaxanthin complex (58.03 ± 0.1 μg/g DW) and the free astaxanthin content (12.25 ± 0.9 μg/g DW) in the extract. Lutein and β-carotene were the other carotenoids identified. Therefore, ethanol was chosen for further optimization studies.

View full abstract

A pilot-scale production of lipase using palm oil mill effluent (POME) as a fermentation basal medium was carried out, and parameters for immobilization of the produced lipase were optimized. Lipase production in a 300-L bioreactor was performed using two proposed strategies, constant power per volume (P/V) and constant tip speed. Moreover, lipase immobilization on different materials was also investigated. Lipase production was performed using liquid-state bioconversion of POME as the medium and Candida cylindracea as the inoculum. The fermentation medium was composed of 1% total suspended solids (TSS) of POME, 0.5% (w/v) peptone, 0.7% (v/v) Tween-80, and 2.2% inoculum. The medium composition was decided on the basis of the medium optimization results of a previous study. The fermentation was carried out for 48 h at 30°C and pH 6. The maximum lipase production was 5.72U/mL and 21.34 U/mL, obtained from the scale-up strategies of constant tip speed and P/V, respectively. Four accessible support materials were screened for their potential use in immobilization. The most suitable support material was found to be activated carbon, with a maximum immobilization of 94%.

View full abstract

Aqueous extracts obtained from five Malaysian brown seaweeds, Sargassum duplicatum, Sargassum binderi, Sargassum fulvellum, Padina australis, and Turbinaria turbinata, were investigated for their abilities to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-induced macrophage RAW 264.7 cell lines as well as to determine their chemical composition. The percentage yield of extracts varied among species, with P. australis having the lowest yield and T. turbinata having the highest yield. The chemical compositions of the extracts showed that the percentage of sulfate ions as well as uronic acid and total sugar content varied significantly. All extracts contained high fucose and inhibited NO secretion in a dose-dependent manner. Extracts of P. australis and T. turbinata dosed at 200 μg/mL were able to inhibit NO secretion by > 75%. Furthermore, cytotoxicity assays revealed that some extracts were moderately toxic, while others were not. Based on these results, brown seaweed of Malaysian origin should be investigated for the production of additional anti-inflammatory compounds.

View full abstract

Biosurfactants are surface-active compounds produced by different microorganisms. The aim of this study was to introduce palm kernel cake (PKC) as a novel substrate for biosurfactant production using a potent bacterial strain under liquid state fermentation. This study was primarily based on the isolation and identification of biosurfactant-producing bacteria that could utilize palm kernel cake as a new major substrate. Potential bacterial strains were isolated from degraded PKC and screened for biosurfactant production with the help of the drop collapse assay and by analyzing the surface tension activity. From the screened isolates, a new strain, SM03, showed the best and most consistent results, and was therefore selected as the most potent biosurfactant-producing bacterial strain. The new strain was identified as Providencia alcalifaciens SM03 using the Gen III MicroPlate Biolog Microbial Identification System. The yield of the produced biosurfactant was 8.3 g/L.

View full abstract

pH-Regulating agents, such as sodium tartrate, disodium succinate, and trisodium citrate, were investigated for their antioxidant activities during the thermal deterioration of vegetable oils. Refined rapeseed and rice bran oils, supplemented with pH-regulating agents and α-tocopherol (0.1%) were heated at 180℃. After heating, acid values (AVs), carbonyl values (CVs), polar material contents, and color (absorbance at 420 nm) of each sample were measured. All pH-regulating agents gave rise to reduced AVs, CVs, and polar material contents of vegetable oils during heating relative to samples not containing a pHregulating agent. Rapeseed and rice bran oils supplemented with sodium tartrate showed the lowest AVs, CVs, polar material contents and absorbances at 420 nm after heating. Sodium tartrate not only retarded the hydrolysis, thermal oxidation, polymerization, and coloration of both oils while heating at high temperatures, but it also showed antioxidant activity at the supplementation level of 0.01%. The antioxidant activity of sodium tartrate was higher than that of α-tocopherol during the deterioration of vegetable oils. Sodium tartrate was particularly effective retarding hydrolysis while heating at high temperatures, resulting in increase of AVs of vegetable oils. Sodium tartrate is therefore expected to be an effective antioxidant for the thermal deterioration of fats and oils during deep-fat frying.

View full abstract

Blends (30:70, 50:50 and 70:30 w/w) of Moringa oleifera seed oil (MoO) with palm olein (PO), palm stearin (PS), palm kernel oil (PKO) and virgin coconut oil (VCO) were prepared. To determine the physicochemical properties of the blends, the iodine value (IV), saponication value (SV), fatty acid (FA) composition, triacylglycerol (TAG) composition, thermal behaviour (DSC) and solid fat content (SFC) tests were analysed. The incorporation of high oleic acid (81.73%) MoO into the blends resulted in the reduction of palmitic acid content of PO and PS from 36.38% to 17.17% and 54.66% to 14.39% and lauric acid content of PKO and VCO from 50.63% to 17.70% and 51.26% to 26.05% respectively while oleic acid and degree of unsaturation were increased in all blends. Changes in the FA composition and TAG profile have significantly affected the thermal behavior and solid fat content of the oil blends. In MoO/PO blends the melting temperature of MoO decreased while, in MoO/PS, MoO/PKO and MoO/VCO blends, it increased indicating produce of zero-trans harder oil blends without use of partial hydrogenation. The spreadability of PS, PKO and VCO in low temperatures was also increased due to incorporation of MoO. The melting point of PS significantly decreased in MoO/PS blends which proved to be suitable for high oleic bakery shortening and confectionary shortening formulation. The finding appears that blending of MoO with other vegetable oils would enable the initial properties of the oils to be modified or altered and provide functional and nutritional attributes for usage in various food applications, increasing the possibilities for the commercial use of these oils.

View full abstract

Formation of a liquid ordered phase in lysophospholipid/cholesterol/1,3-butanediol/water and lysophospholipid/ceramide/1,3-butanediol/water systems was investigated. Differential scanning calorimetry confirmed that a liquid ordered phase was formed in the lysophospholipid/cholesterol/1,3-butanediol/water system similar to that in phospholipid systems. The structure of liquid ordered phase was analyzed by using X-ray scattering measurements. It was revealed that the liquid ordered phase has a lamellar structure in which the hydrophobic chains are less ordered than in α-type crystals. On the other hand, in the lysophospholipid/ceramide/1,3-butanediol/water system, a liquid ordered phase was not formed.

View full abstract

Artemisia argyi Lévl. et Van., a perennial herb with a strong volatile odor, is widely distrbuted in the world. Essential oil obtained from Artemisia argyi was analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 32 components representing 91.74% of the total oil were identified and the main compounds in the oil were found to be eucalyptol (22.03%), β-pinene (14.53%), β-caryophyllene (9.24%) and (-)-camphor (5.45%). With a further isolation, four active constituents were obtained from the essential oil and identified as eucalyptol, β-pinene, β-caryophyllene and camphor. The essential oil and the four isolated compounds exhibited potential bioactivity against Lasioderma serricorne adults. In the progress of assay, it showed that the essential oil, camphor, eucalyptol, β-caryophyllene and β-pinene exhibited strong contact toxicity against L. serricorne adults with LD₅₀ values of 6.42, 11.30, 15.58, 35.52, and 65.55 μg/adult, respectively. During the fumigant toxicity test, the essential oil, eucalyptol and camphor showed stronger fumigant toxicity against L. serricorne adults than β-pinene (LC₅₀ = 29.03 mg/L air) with LC₅₀ values of 8.04, 5.18 and 2.91 mg/L air. Moreover, the essential oil, eucalyptol, β-pinene and camphor also exhibited the strong repellency against L. serricorne adults, while, β-caryophyllene exhibited attracting activity relative to the positive control, DEET. The study revealed that the bioactivity properties of the essential oil can be attributed to the synergistic effects of its diverse major and minor components. The results indicate that the essential oil of A. argyi and the isolated compounds have potential to be developed into natural insecticides, fumigants or repellents in controlling insects in stored grains and traditional Chinese medicinal materials.

View full abstract

Among famous medicinal plants with known antioxidant activity; black seed (Nigella sativa, NS) and garlic (Allium sativum) which have been used in traditional medicine. In recent years, rates of metabolic syndrome (MS) have been increasing globally. The present work was designed to study the potential protective effects of black seed and raw garlic homogenate against fructose-induced MS in rats and to assess the benefits gained from their combination. Fifty male albino Wistar rats were divided into 5 groups. A control group was allowed to feed on normal chow and drink tap water. MS group was fed the same diet plus 10% fructose in drinking water. Treated groups received NS or garlic either alone or in combination as oral supplements along with high fructose diet for 8 weeks. Results revealed that body weight, liver weight, fasting blood glucose, serum triglycerides (TG), total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) levels were significantly increased while high density lipoprotein cholesterol (HDL-C) and the activities of Lactate dehydrogenase (LDH), glucose -6-phosphate dehydrogenase (G-6-PHD) and catalase in liver tissues were significantly decreased in MS group compared to the control group. Administration of NS or garlic either alone or in combination significantly ameliorated all the abovementioned altered parameters. Treatment with both NS and garlic showed the utmost reduction in serum LDL-C and TG levels and could restore the activities of the studied enzymes in liver nearly to normal values. It was concluded that both NS and garlic were effective in attenuating multiple abnormalities of MS. Combination of these medicinal plants may have additional effectiveness in reducing serum TC, LDL-C and increasing HDL-C levels which could be a step in the prevention and management of MS.

View full abstract