Antibacterial effect of modified sago starch-alginate edible film incorporating lemongrass oil at various concentrations was studied. Edible films were prepared from a mixture of modified sago starch and alginate. Lemongrass oil (0.1 - 0.4%, v/w) and glycerol (0 and 20%, w/w) were incorporated in the films to act as natural antimicrobial agent and plasticizer, respectively. The films were characterized for antibacterial activity against food pathogenic bacteria such as Escherichia coli O157:H7, Salmonella Enteritidis and Staphylococcus aureus. The edible film exhibited antibacterial activity against Escherichia coli O157:H7 and Salmonella Enteritidis by using agar diffusion assay method. For films tested against Escherichia coli O157:H7, the zone of inhibition increased significantly (p < 0.05) with addition of lemongrass oil at all levels both in the presence and absence of glycerol. The films also significantly (p < 0.05) inhibited the growth of Salmonella enteritidis only with 0.4% lemongrass oil (in the presence and absence of glycerol). However, the films containing lemongrass oil did not show any inhibition effect on Staphylococcus aureus.
Tropical fruits are of great significance in human diet due to abundant nutritional and antioxidants components. The processing or consumption of these fruits generates waste,which is generally disposed of into the ecosystem. However, efforts are in line to evaluate the nutritional worth and possible reuse of fruit processing waste by valorizing the waste in an optimal way. In this review, by-products of rambutan fruit waste, i.e., seed and peel, are signified with respect to their nutritional values and possible applications. Peel and seed cumulatively share almost around 50% of whole rambutan fruit by weight. Peel that is rich in phenolics and ellagitannins have applications as a natural antioxidant system. However, abundant fat content (14−41%) with high oleic acid, renders the seed a novel source of vegetable fat. Besides, possibilities of using seed fat in chocolate (30 wt.% substitute) and personal care products are also one of the focus. Nanostructured seed fat is reported for encapsulation off at-soluble vitamins (e.g., vitamin E). Additionally, the seed contains the most of the essential and non-essential amino acids that are concentrated as protein concentrate. The physico-functional properties of defatted seed flour and seed mucilage are also elaborated. Similarly, rambutan seed oil and peel utility as filler in packaging, bio-coagulant, bio-sorbent and alternative biodiesel are also mentioned. Despite diverse applications, gaps are still there to further evaluate and validate the potential of rambutan processing by-products. Thus, to avail the manifold potential, fruit by-products’ applications should be scaled up to transform the maximum waste into best.
In this study, we evaluated and characterized microbial cellulose produced from Kombucha after eighth day of fermentation by employing SEM, FTIR, X-ray diffractometry, adsorption isotherm, and by measuring the swelling properties. Results on SEM revealed microbial cellulose layer to be composed of a compact cellulose ultrafine network like structure. FTIR spectra showed the presence of a characteristic region of anomeric carbons (960 – 730 cm-1), wherein a band at 891.59 cm-1 confirmed the presence of β, 1-4 linkages. Results of FTIR spectra also showed microbial cellulose to be free from contaminants such as lignin or hemicellulose, which are often present in plant cellulose. X-ray diffraction studies exhibited the overall degree of crystallinity index for MCC to be slightly lower than that of microbial cellulose. Results on swelling properties indicated microbial cellulose to possess higher fiber liquid retention values (10-160%) compared to commercial MCC (5-70%). The adsorption isotherm curves showed similarities between microbial cellulose with that of pure crystalline substance. Overall, results obtained in this study were comparable with the commercial microcrystalline cellulose, indicating that the process developed by us can be explored industrially on a pilot scale.
The yield and properties of cellulose produced from bacterial fermentation of black tea broth (known as Kombucha) were investigated in this study. The tea broth was fermented naturally over a period of up to 8 days in the presence of sucrose. Tea broth with a sucrose concentration of 90 g/l produced highest yield of bacterial cellulose (66.9%). The thickness and yield of bacterial cellulose increased with fermentation time. The bacterial cellulose production increased correspondingly with increased surface area:depth ratio. Changes in pH were related to the symbiotic metabolic activities of yeasts and acetic acid bacteria, and the counts of both of these in the tea broths were relatively higher than those in the cellulose layer. Findings from this study suggest that the yield of cellulose depends on many factors that need to be optimized to achieve maximum yield.
Duck feet collagen was added to threadfin bream and sardine surimi to study its effect on physicochemical properties such as folding test, gel strength, cook loss, water holding capacity, expressible moisture, texture profile analysis and colour measurement. As compared to commercial fish scale collagen and cow collagen, the addition of duck feet collagen resulted in a significant improvement in the quality of the sardine surimi. Duck feet collagen was able to improve the folding test score of sardine surimi from 3.00 to 5.00; gel strength was increased from 275.70 g.mm to 2682.70 g.mm and hardness of gel was increased from 1.12kg to 6.00kg. Addition of duck feet collagen improved the gel strength of threadfin bream surimi from 1696.70 g.mm to 5579.40 g.mm and hardness of gel was increased from 4.55kg to 10.32kg. Colour of threadfin bream and sardine surimi also improve with the addition of duck feet collagen. The lightness was increased from 66.47 to 66.89 (threadfin bream) and from 62.32 to 63.60 for sardine. The results suggest that duck feet collagen has potential as an alternative source of protein additive for the improvement of the physicochemical properties of low grade surimi.
The effects of different types of low-sweetness sugar (lactitol, maltodexrin, palatinit, polydextrose,
trehalose) on the physicochemical properties of threadfin bream (Nemipterus spp.) surimi during six months of frozen storage were investigated. The characteristics analyzed were moisture content, pH, water-holding capacity, whiteness, folding test, gel strength, expressible moisture, and texture profile analyses. Generally, the cryoprotective effectiveness decreased as the storage time increased. Polydextrose was able to maintain a water-holding capacity of 77.0%, 98.6% whiteness, a folding test value of 100%, and a gel strength of 53.6% compared with its initial value during six months of frozen storage. Meanwhile, sucrose was able to maintain a water-holding capacity of 80.3%, 98.6% whiteness, a folding test value of 75%, and a gel strength of 56.8%
compared with its initial value. Raw surimi was able to maintain water holding capacity of 62.2%, 98.7% whiteness, a folding test value of 75%, and a gel strength of 36.0% compared with its initial value. It is suggested that, polydextrose as a potential alternative cryoprotectant to replace other low-sweetness sugars.
Starch blend films made from sago and mung bean were prepared by casting with glycerol as the plasticizer and subsequently exposed to ultraviolet (UV) irradiation for 2 h. The films were characterized by thickness, moisture sorption isotherms, X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. All films produced were colorless while incorporation of glycerol resulted in more flexible and manageable films. Moisture sorption isotherms for all films showed sigmoidal shape and the control films showed slightly higher curve than treated films. While for X-ray analysis, the control and treated films for all formulations showed similar pattern, however for treated films showed more crystalline character. UV radiation showed affect on X-ray diffraction and sorption isotherms; however the UV radiation did not affect the spectra pattern of FTIR.
Edible films were prepared from a mixture of partially hydrolyzed sago starch and alginate (SA). Lemongrass oil (0.1% to 0.4%, v/w) and glycerol (0% and 20%, w/w) were incorporated in the films to act as natural antimicrobial agent and plasticizer, respectively. The films were characterized for antimicrobial activity, water vapor permeability (WVP), tensile strength (TS), percent elongation at break (%E), and water solubility (WS). Fourier transform infrared (FTIR) spectroscopy was conducted to determine functional group interactions between the matrix and lemongrass oil. The zone of inhibition was increased significantly (P < 0.05) by addition of lemongrass oil at all levels in the presence and the absence of glycerol. This indicates that the film containing lemongrass oil was effective against Escherichia coli O157:H7 at all levels. In the absence of glycerol, the tensile strength of film decreased as the oil content increased, but there was no significant (P > 0.05) difference in percent elongation. The percent elongation at break and WVP values for film with 20% glycerol was found to be increased significantly (P < 0.05) with an increase in lemongrass oil content. Addition of lemongrass oil did not have any interaction with the functional groups of films as measured by FTIR.
Hemicelluloses from oil palm frond (OPF) were extracted using 3 M potassium hydroxide (KOH) for 4 h at 40 degrees C with stirring at 400 rpm to obtain hemicelluloses A and B. The total yield of the hemicellulose isolated from OPF was 33% (dry weight). Both hemicelluloses A and B were then subjected to hydrothermal treatment at 121 degrees C and 1.03 x 10(5) Pa for 10, 30, and 50 min. Physicochemical characterizations of hydrothermally treated hemicelluloses, such as Klason lignin content and reducing sugar content, were performed to study the effect of autohydrolysis processing on OPF-derived hemicelluloses. It was shown that Klason lignin content in hemicellulose A was higher than that in hemicellulose B and decreased after hydrothermal treatment. Hydrothermal treatment enhanced the solubility of hemicelluloses, which reflects their higher reducing sugar content. Monosaccharide analysis using HPLC showed that xylose was the predominant monosaccharide for both hemicelluloses A and B.
The direct consumption of vegetable proteins in food products has been increasing over the years because of animal diseases, global shortage of animal protein, strong demand for wholesome and religious (halal) food, and economic reasons. The increasing importance of legume and oilseed proteins in the manufacturing of various functional food products is due to their high-protein contents. However, the greatest obstacle to utilizing these legumes and oilseeds is the presence of antinutrients; but these antinutrients can be successfully removed or inactivated by employing certain processing methods. In contrast, the potential negative impact of the antinutrients is partially balanced by the fact that they may have a health-promoting role. Legumes and oilseeds provide well-balanced amino acid profiles when consumed with cereals. Soybean proteins, wheat gluten, cottonseed proteins, and other plant proteins have been used for texturization. Texturized vegetable proteins can extend meat products while providing an economical, functional, and high-protein food ingredient or can be consumed directly as a meat analog. Meat analogs are successful because of their healthy image (cholesterol free), meat-like texture, and low cost. Mycoprotein is fungal in origin and is used as a high-protein, low-fat, health-promoting food ingredient. Mycoprotein has a good taste and texture. Texturized vegetable proteins and a number of mycoprotein products are accepted as halal foods. This article summarizes information regarding the molecular, nutritional, and functional properties of alternative protein sources to meat and presents current knowledge to encourage further research to optimize the beneficial effects of alternative protein sources.
The effects of sodium chloride (NaCl) (3.5%) solution and polysaccharides, such as carboxymethyl cellulose (CMC) (0.1, 0.3 and 0.5%) and gum arabic (5, 10 and 15%), on the physicochemical properties, antioxidant capacity and sensory characteristics of bitter gourd juice were investigated. An increase in the concentration of CMC and gum arabic significantly was observed to increase the lightness (L value) and the viscosity (mPas) of bitter gourd juice at all levels. Increased concentrations of gum arabic significantly increased the total soluble solids. The bitter gourd fruit treated with NaCl solution produced the highest lightness (L value) and scavenging activity of free radical 2,2-diphenyl-1-picrylhydrazyl of bitter gourd juice. Increased concentration of gum arabic up to 15% significantly increased the total phenolic content. The addition of 5% gum arabic effectively reduced the bitterness of the bitter gourd juice. Viscosity of the juice resulted in negative correlation for bitterness.
Effects of phosphorus content (510 to 987 ppm) on the gelatinization and retrogradation of 6 potato cultivars (Benimaru, Hokkaikogane, Irish Cobbler, Konafubuki, Sakurafubuki, and Touya) were studied. Pasting properties were analyzed by RVA, thermal properties by DSC, and mechanical properties of the starch gels by TA. Phosphorus was positively correlated with swelling power (r= 0.84) and negatively correlated with solubility (r= 0.83). Phosphorus content showed significant effect on certain pasting properties of potato starch such as peak viscosity, breakdown, and setback. Phosphorus content showed a significant positive correlation with peak viscosity (r= 0.95) and breakdown (r= 0.90). Increasing concentration of phosphorus tends to decrease the setback. Phosphorus content had no influence on thermal properties and mechanical properties of potato starch gel.
The long agonistic protocol for controlled ovarian hyperstimulation (COH) is effective and used most often, thus is considered the gold standard. Therefore any new regimen has to be compared in its results with those obtained with the long protocol. This report compares the efficacy of GnRH agonist and antagonist in a retrospective study of IVF/ICSI carried out in a tertiary teaching hospital from 2003 to 2006. Only the first COH cycle followed by IVF-ICSI from 200 couples (agonist = 120 and antagonist = 80) were analysed. The end points studied included the number of oocytes recovered, number of mature (MII) oocytes, fertilization, cleavage, morphology based embryo quality, pregnancy rate, quantity and cost of gonadotrophin. The average age of female subjects was 35.1 +/- 4.7 years with 50% being 35 years and above. Major infertility factors were tubal blockage, male factor and endometriosis altogether comprising 68%. GnRH agonist and antagonist cycle parameters were comparable except lesser amount of gonadotrophin was used with lower resultant costs (both p < 0.0005) in antagonistic regime. Antagonist regime produce somewhat more good quality embryos (p = 0.065), an insignificant difference. A clinical pregnancy rate per embryo transfer of 16.3% in agonist and 20.6% in antagonist regime was achieved respectively. In conclusion, GnRH antagonist protocol produced a COH response, embryonic development and pregnancy rates on par to GnRH agonist regime. Moreover GnRH antagonist protocol required a shorter stimulation period plus fewer complications. Hence GnRH antagonist regime provided means for a friendlier, convenient and cost effective protocol for patients.
Low dose stimulation (LS) is emerging as an alternative regime in assisted reproductive technology (ART). This study aimed to compare the cost-effectiveness of LS to the high dose GnRH antagonist (Atg) regime.