Prevention of Protein Oxidation in Chicken Meat during Chilled Storage Using Chitosan Gelatin Films with Green Tea Extracts

In present study, the usability of chitosan and gelatin (1:1) films incorporated with green tea extract (GTE) to improve the shelf life of the chicken meat stored in chilled condition was evaluated. The extract of green tea was evaluated for its phenolic content, antioxidant activity and ferric ion chealating ability. The ChGel films possessed antimicrobial activity and inactivated approximately 3 log cfu/ ml of K. pneumoniae, S. typhi var. Weltevreden, S. typhi var. Oslo, Y. enterocolitica, E. feacalis, B. cereus, E. coli and S. aureus in 3 hours. Incorporation of GTE influenced the optical and mechanical properties of the films. Chicken samples without films were observed to be microbiologically safe for not more than 6 days, while ChGel and ChGel-GTE films improved the microbial safety of chicken samples till day 13. ChGel-GTE films also prevented lipid peroxidation in samples as evident by TBARS value (day 10: control: 1.14; ChGel-GTE: 0.21 mg MDA eq/kg). Protein oxidation during chilled storage of chicken was also prevented by ChGel-GTE by inhibiting protein carbonylation, loss of free thiols groups in protein and lowering the number of disulphde bonds. This study supports use of ChGel films with GTE for enhancing the safety of stored chicken meat not only by maintaining the microbial quality of the samples but also preventing oxidative changes which can hamper the functional, nutritional and sensorial properties.

A New Test of Filterability for Unprocessed Wines Evaluation of the Enzyme Efficiency

A new Test of Filterability has been developed. Measurements carried out with different types of wines indicate that the new filterability index is a useful tool for understanding and predicting the propensity to fouling of treated or untreated wines, e.g. with or without enzyme addition. The measurement method used in the Test of Filterability, requires only one type of membrane for all types of wine, and uses the same equipment as the traditional Fouling Index. Numerous trials have demonstrated that the filtration of wines is governed by standard blocking law. The definition of the new Test of Filterability, based on this filtration law, is proposed. The choice of membrane and the selection of the optimal pore size were based on the results of the experiments. Current methods used for the determination of fouling properties in wine filtration have been developed for the membrane filtration of small quantities of suspended matter. Enzyme treatment is a process often used in wine clarification. The new Test of Filterability indicates the best conditions for the filtration of all types of wines. The test is easy to implement and has been validated with various wines. This new Test of Filterability is an important tool for winemakers as it constitutes a simplified test of a wine's filterability. The new test may also be used to determine the filtration process that is best adapted to each wine while reducing the number of operations. The same approach may be adopted for the filtration of other liquids.

Extraction of Kaempferitrin and Astragalin from Justicia Spicigera by Supercritical Fluid Extraction and Its Comparison with Conventional Extraction

A study of supercritical fluid CO2 extraction of kaempferitrin (KM) and astragalin (KG) from Justicia spicigera (muicle) was conducted. A 33 Box-Behnken design was used to analyze the effects of pressure (200-300 bar), temperature (40-60° C), and co-solvent flow rate (0.5-1.0 mL/min). The highest KM and KG concentration were achieved at a pressure of 300 bar, a temperature of 60° C, and co-solvent flow rate of 1.0 mL/min (ethanol 99.5 %), with a constant CO2 flow rate of 5 mL/min and extraction time of 180 min. Under these conditions, the experimental values for KM and KG (115.08±2.81 and 56.63±9.02 mg/100 g of dry powder, respectively) were similar to those calculated by the models (109.0 and 44.07 mg/100 g of dry powder, respectively). The use of 70 % ethanol as co-solvent in the supercritical extraction process considerably improved the yields of KM and KG (562.71±156.85 and 79.90±18.03 mg/100 g of dry powder, respectively) compared to the 99.5 % ethanol extractions. The conventional extraction showed the highest yields of KM and KG (574.20±65.10 and 113.10±15.06 mg/100 g of dry powder, respectively) at 70° C and extraction time of 120 min. Adequate yields were achieved of KM and KG by supercritical fluid extraction compared with conventional extraction (98 and 70 %, respectively); therefore supercritical fluid extract of J. spicigera could be used in the development of functional foods, as well as its possible use in traditional medicine by the health professionals.

Effect of Cocoa Powder, Banana Pulp and Bambara Nut Inclusion on Nutritional and Sensory Acceptability of Yoghurt

This study was to investigate the effect of utilizing milk powder with addition of Cocoa powder, Banana pulp and Bambara nut extract for the production of functional yoghurt. The yoghurt samples were produced by 10% inclusion of each of the food item into reconstituted skimmed milk powder, inoculated with starter culture (streptococcus.thermophilus and Lactobacillus. Bulgaricus) and allowed to ferment for 9hr. The nutritional properties (Proximate, Brix, PH, Flavonoid, Vitamin C, antioxidant activity) and sensory characteristics (colour, taste, aroma and over all acceptability) were determined. Significant differences (p<0.05) existed among the nutritional and sensory properties of the yogurts. The results showed that the inclusion of used food items improves the Protein, Ash and Energy content of the products. The sample with Cocoa powder had the highest antioxidant activity (2.75mg/100g) which is significantly higher at (p<0.05) than Banana pulp (2.64mg/100), Bambara nut extract (2.44mg/10g) and control (2.25mg/100g) which was the least. The sample with Banana pulp inclusion has highest score (5.70) for taste and overall-acceptability (5.90) using 7-point score ranking and was the most preferred. The microbial load of all the samples were within the limits specified of acceptable counts, making the products safe for consumption as at the time the products were evaluated.

Development of Sugar Free and Fortified Chocolates with D-Optimal Design Approach

The increasing numbers of overweight or chronically obese individuals have led the market to produce sweet snacks and desserts that are low in calories, low in fat or low in sugar. Sugar replacers have low calorific value and lower glycaemic index as compared to sucrose which not only helps in controlling weight but also is safe for diabetics. The study is aimed to develop a sugar free chocolate by using a combination of various zero calorie sweeteners i.e., stevia, isomalt and erythritol through response surface methodology (RSM). The final run optimized by RSM consists of 21.9g cocoa butter, 5.1g erythritol, 0.10g stevia and 14.9g isomalt. Organoleptic evaluation of modified chocolates was evaluated using 9 point hedonic scale for the parameters like, appearance, color, aroma, taste, texture, mouthfeel, aftertaste and overall acceptability. The overall acceptability of sugar free chocolates was found to be 8.9. Further, the fortification of chocolates was done with the help of vitamins and minerals rich fruit powders such as beetroot powder, jamun seed powder and pink pithaya powder (dragon fruit). Vitamins and minerals analysis was performed for sugar free chocolate fortified with beetroot. Shelf-life study of sugar free chocolate fortified with beetroot was carried out.

Effect of Drying Temperature on Physiochemical Properties of Powder from Blanched and Unblanched Lemon Peel and Sensory Quality Evaluation of the Powder Fortified Biscuits

Preparation of biscuit incorporating lemon peel powder can be a new approach in formulating fortified fast food. This investigation was made to evaluate quality of prepared biscuits with lemon peel powder. The effect of temperature on drying time and physiochemical properties of lemon peel powder and their effects on biscuits were also examined. Two drying temperatures (650C and 750C) were employed for both blanched and unblanched lemon peel. The formulated biscuit samples incorporating 1 % lemon peel powder were compared with control biscuits which were prepared with 100% wheat flour. It took longer time (18 hr) for drying of blanched sample at 65 0C whereas shorter time (8 hr) was required for that of blanched sample at 750C. There was a significant decrease in the physiochemical properties of lemon peel powder with the increase of temperature except protein and fibre content. In addition, moisture content of the unblanched sample was found to be lower than the blanched sample at the same temperature. Significantly higher ascorbic acid was obtained by the unblanched samples. Protein and fibre content for both unblanched and blanched sample at the same temperature were found to be higher. All the samples were significantly different at 5% level of significance for overall acceptability. Biscuits prepared with unblanched dried lemon peel powder (at 650C) sample secured the highest score in case of all the sensory parameters. Therefore, quality fortified biscuit can be prepared commercially by incorporating 1 % lemon peel powder in wheat flour for the fast food consumer.

Cloud Point Extraction Used for Separation and Preconcentration of Trace Elements in Food Samples: A Review of Recent Applications

Food safety analysis involves many subfields. One of them is inorganic analysis aimed to the quantification of various trace elements. The main attention in this field is paid to toxic, potentially toxic, and essential trace elements. However in many cases, direct quantification of trace elements in a complex food matrix is almost impossible. To resolve this problem, a combination of a suitable separation procedure with a reliable quantification method is required to deliver accurate results. One of the separation techniques that is currently receiving considerable attention is cloud point extraction (CPE). The use of optimized CPE procedures with commonly available spectrometric methods (e.g., UV-Vis spectrophotometry, flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry, hydride generation atomic absorption spectrometry, cold vapor atomic absorption spectrometry, inductively coupled plasma optical emission spectrometry) provides the powerful tool for reliable quantification of many trace elements (e.g., Al, As, Cd, Cu, Hg, Pb, Mn, Ni, Sb, Se, Sn, Zn, and many others) in various types of food matrices (e.g., fresh vegetables, ground grain samples, canned food samples, various powdered food samples, and many others), as documented by studies included in this review.

Protein Extractability and Thermally Induced Gelation Properties of African Locust Bean Proteins (Parkia biglobosa Jacq. R.Br)

African locust bean (AfLB) protein isolates could be an interesting alternative to the use of soy as an ingredient for the development of new protein-rich products. From AfLB seed flour, the protein extractability yields by aqueous extraction were determined as a function of pH and ionic strength. Then thermally induced gelation of various protein suspensions relating to protein concentration was studied. The most critical factors affecting extractability were the pH and the presence of fat. As a function of the extraction process, the extraction yield of protein from AfLB flour ranged from 30 to 65%. Two major fractions of proteins detected in AfLB seeds were albumins and globulins, comprising four families: legume-like protein, vicilin-like proteins, convicilin, and albumins. The globulin isolate had the lowest solubility at pH 3.5-4 and the highest at pH 8-10. The solubility of albumin isolate was lightly affected by pH and ionic strength. At pH 7, the minimum protein concentration for thermal gel formation ranged from 55 to 120 g/L as function purified state of proteins. The less purified extract with a simpler process made it possible to obtain a gel needing a lower protein concentration. This last way seems promising to the development of new foods based on African locust bean flour.

Optimization of Processing Parameters to Achieve Superior Quality and Maximum Recovery of Canola Oil

Aim of the present study was to improve the efficiency of processing to achieve a superior quality of canola oil with better recovery. Three sets of canola oil containing crude, neutralized, bleached, deodorized oils and deodorizer distillates (DD) were collected from edible oil processing industries. Important physicochemical properties of the oil were evaluated in all three sets including unsaponifiable matter, phosphorus content and soap content. The industrial processing of set I and II was found to be satisfactory as compared to set III. Therefore, set III was selected for the optimization of different processing parameters during each stage of processing. For neutralization, bleaching and deodorization different parameters were optimized to achieve a better quality of the finished product, good recovery and control of the processing cost. After optimization, physicochemical characteristics of neutralized, bleached, deodorized oil and its DD were evaluated. Also, the loss and recovery of neutral oil were calculated in each processing stage. The results of the present study showed that a slight variation of processing parameters leads to a great impact on the quality and recovery of the canola oil. High contents of free fatty acids (FFA) in DD indicated that it could be used as a potential source of biodiesel production.

Studies on Alum as Milk Coagulating Agent in the Manufacture of Paneer – An Indian Cottage Cheese

Alum is a white crystalline double sulphate of aluminum and potassium that is commonly used as an astringent. Utilising its protein binding property, alum was studied as coagulating agent of milk in the preparation of paneer. Paneer is a soft variety of cottage cheese very popular in Indian sub-continent, used in various culinary dishes. Its preparation essentially involves acid coagulation of hot milk and pressing of the hot coagulum to form a compact block which is then cooled by immersing in chilled water. Citric acid and vinegar are commonly used as coagulating agents of milk during paneer manufacture. However, when alum was used as a coagulating agent, it was observed that most of the proteins were amalgamated during coagulation process resulting in enhanced yield of paneer. It also resulted in reduced solids losses in whey. However, use of alum resulted in a slight astringency in paneer, hence it was recommended to be used in combination with common coagulant i.e. citric acid. The solids content (losses) in whey were 6.62, 6.08, and 6.32 %, respectively for citric acid, alum and citric acid + alum mixture used as coagulating agents. Similarly, the yields of paneer were 16.42, 19.04 and 16.99 %. The alum coagulated paneer looked glossy and attractive which was indicated by reflectance values of 83.75% as against 79% for control paneer sample. The paneer made by alum coagulation had slightly brittle texture.