Shelf Life and Quality Attributes Of Fresh Beef Infused With Organic Acids.

Fresh beef is a highly perishable food. It has a shelf life of one day at ambient temperature and a few days at refrigerated temperature. This study was conducted with the objective of extending the shelf life of fresh beef by infusing organic acids such as citric, tartaric, acetic and lactic acids, and combination of the organic acids with sodium chloride. Fresh beef (longissmus do@ purchased from the local market were sliced and were infused with citric, acetic, lactic and tartaric acids in concentration of 0.5%, 0.75% and 1 %, and combination of 1.00% of citric and acetic acids with and without sodium chloride by placing samples in vacuum desiccators and pulling the vacuum to 29.5 in. Hg. for 20 min.,. All samples were packed in vacuum packs (22 (L) x 18 (w) crn. and stored at S°C for 28 days. pH, A, Total Plate Count (TPC), Thiobarbaturic acid values, Hunter colour values , instrumental texture, proximate composition were determined. The pH values of treated samples dropped from the initial pH of 5.30 (untreated) to 4. 20 - 4. 47 and upon storage, the pH values of all sampies increased gradually. The TPC values were lower than 10' CFUlg on day 16, 20 and 28 in samples treated with 0.5%, 0.75% and 1.00% acids, respectively. The proximate com p s iti on of treated samples was affected by infusion process. The instrumental texture of fresh beef was harder upon treatment. The maximum shelf life of treated beef was 12 - 24 days for samples treated with 0.5% of all acids, 16 - 24 days for samples treated with 0.75% and 20 - 28 for samples treated with 1.00%. Citric acid in concentration of 1.00% gave the best effect which was followed by acetic acid. In citric and acetic acids and citric and acetic acids with sodium chloride combinations, the later in the ratio of 2:1 was more effective in decreasing the initial pH of fresh beef immediately after infusion. Increasing concentration of NaCl in the infusion solution resulted in the smaller decrease in the pH values. The TPC value was observed in samples treated with 2:1 citric: acetic acids. The growth of S.aureus and E.coli 0157:H7 were significantly (B0.05) decreased by 0.85 loglo and 0.73 logto, respectively. The initial thiobarbituric acid value in untreated fresh beef was 0.735 mg MDNkg which significantly (pc 0.05) decreased in all treated samples. At the end of storage study, lowest TBA values were obtained in samples treated with 2:l citric and acetic. The increase in the addition of NaCl caused a parallel increased in TBA values. For colour, Hunter 'b' and 'L' values increased with storage time while 'a' decreased significantly (R0.05). The processed beef burger during chilled storage had a storage life of 8 days

An in vitro evaluation of films prepared from gelatin – Carica papaya methanolic extract for wound healing

This paper is a part of research aiming at preparing biodegradable films containing gelatin and Carica papaya extract for wound healing purposes in rats. Carica papaya leaves were collected and extracted using methanol aqueous method (20% methanol: 80% water). Eleven films (F1–F11) of Carica papaya extract (0–500) and gelatin (1000 mg) were prepared and investigated for selected in vitro parameters which include pH, thickness, folding endurance, water absorption capacity, tensile strength and extract released studies. Increasing concentrations of the added Carica papaya extract dropped the pH value from 7.3 ± 0.1 to 5.2 ± 0.1. Blank gelatin film had the highest value of the thickness (22.8 ± 0.9 µm). Folding endurance increased significantly (p<0.05) in both blank and composite films. In blank films the values of the folding endurance increased from 122.7 ± 3.5 – 187.6 ± 3.5 while in composite ones the values increased from 232.0 ± 8.8 to 258.3±2.5. Tensile strength value increased with increasing the addition of Carica papaya extract significantly (p<0.05) from 100.4 ± 3.4 N/cm2 to 191.5 ± 3.6 N/cm2. In contrast, within the composite films the highest addition of Carica papaya decreased the tensile strength value significantly (p<0.05) from 332.8 ± 2.2 to 84.10 ± 6.1 N/cm2. Significant differences (p<0.05) were noticed in the values of extract release. The maximum percentage of extract release was 96.6% which was scored in formulation 7 of the films (F7) while the minimum percentage of the extract release was 69.8% which was recorded in formulation 9 of the films (F9).  In conclusion, the films contained high concentrations of Carica papaya extract gave promising in vitro results and are recommended to be used for wound healing applications

An in vitro evaluation of films prepared from gelatin – Carica papaya methanolic extract for wound healing

This paper is a part of research aiming at preparing biodegradable films containing gelatin and Carica papaya extract for wound healing purposes in rats. Carica papaya leaves were collected and extracted using methanol aqueous method (20% methanol: 80% water). Eleven films (F1–F11) of Carica papaya extract (0–500) and gelatin (1000 mg) were prepared and investigated for selected in vitro parameters which include pH, thickness, folding endurance, water absorption capacity, tensile strength and extract released studies. Increasing concentrations of the added Carica papaya extract dropped the pH value from 7.3 ± 0.1 to 5.2 ± 0.1. Blank gelatin film had the highest value of the thickness (22.8 ± 0.9 µm). Folding endurance increased significantly (p<0.05) in both blank and composite films. In blank films the values of the folding endurance increased from 122.7 ± 3.5 – 187.6 ± 3.5 while in composite ones the values increased from 232.0 ± 8.8 to 258.3±2.5. Tensile strength value increased with increasing the addition of Carica papaya extract significantly (p<0.05) from 100.4 ± 3.4 N/cm2 to 191.5 ± 3.6 N/cm2. In contrast, within the composite films the highest addition of Carica papaya decreased the tensile strength value significantly (p<0.05) from 332.8 ± 2.2 to 84.10 ± 6.1 N/cm2. Significant differences (p<0.05) were noticed in the values of extract release. The maximum percentage of extract release was 96.6% which was scored in formulation 7 of the films (F7) while the minimum percentage of the extract release was 69.8% which was recorded in formulation 9 of the films (F9).  In conclusion, the films contained high concentrations of Carica papaya extract gave promising in vitro results and are recommended to be used for wound healing applications

Physico-Chemical, Thermal and Rheological Properties of Various Fish Protein-Sago Starch Formulas in Keropok Lekor

This study was conducted to investigate the interaction between fish protein and sago starch using keropok lekor as a model with the following objectives: to study the thermal and physical properties of the model, to optimize the contents used in the model based on their thermal and rheological properties, to study the effects of sodium chloride and sucrose on transition temperatures of gelatinization and to investigate the effect of sodium chloride and sucrose on cooking time of the model. The ingredients used in preparing the formulations were red tilapia (Oreochromis spp.) minced fish, sago starch (Metroxylon sagu), and water in the ranges of 20 - 50, 10 - 40 and 10 - 35, respectively. A two-level factorial design was carried out to obtain the experimental formulations of the model. Differential scanning calorimetry (DSC), texture profile analysis (TPA), sensory evaluation and the changes in thermophysical properties such as thermal conductivity (k), specific heat capacity (Cp), density (ρ), thermal diffusivity (α) and the effects of sodium chloride and sucrose concentrations on the cooking time of the optimized fish protein-sago starch model were conducted. The onset temperatures (To) of the different formulations of the fish protein - sago starch model varied from 60.9 ± 0.5 - 80.8 ± 0.4oC with an average value of 70.9 ± 0.5oC. The formulations had peak temperatures of gelatinization that varied from 65.5 ± 0.1 - 86.0 ± 0.4oC with average value of 75.8 ± 0.3oC. Increasing the ratios of the minced fish in the formulations was found to be the most significant factor affecting the values of To and Tp. The highest hardness value 50.9 N was obtained in the sample formulated with 5: 4: 1 minced fish: sago starch: water, respectively followed by 45.0 N which was obtained in the sample formulated with the ratios of 3.5 minced fish 4 sago starch: 2.25 water. The sensory evaluation study showed that the panelists preferred the model formulated with 2: 1: 1 minced fish: sago starch: water followed by 3.5: 2.5: 2.25 of the components, respectively. The optimum formulation of the model was highly dependant on the ratios of fish protein: sago starch. The addition of NaCl to the optimized formulation resulted in the shifting of the To from 82.2 ± 0.9oC to 98.2 ± 0.1oC, Tp from 94.8 ± 0.2oC to 106.2 ± 0.3oC and Tc from 108.0 ± 0.9oC to 116.3 ± 0.2oC. However, the addition of sucrose shifted To from 82.2 ± 0.9oC to 111.4 ± 0.2oC, Tp from 94.8 ± 0.2oC to 118.2 ± 0.2oC and Tc from 108.0 ± 0.9oC to 119.3 ± 0.3oC. During frying an increase in the thermal conductivity (k), specific heat capacity (cp) and thermal diffusivity (α) values was observed. The k value of the model increased dramatically from 0.418 to 0.584 W/m2.oC in the control. The calculated k values confirmed that the NaCl and sucrose caused an increase in k values of the model from 0.419 to 0.585 W/m2.oC for NaCl and from 0.423 to 0.588 W/m2.oC for sucrose treated ones. The calculated values of thermal diffusivities of the model varied from 1.19 x 10−7 to 1.51 x 10−7 m2 s−1 during deep - fat frying. In summary, it can be concluded that the thermal properties of the model were highly dependant on the ratios of fish protein, sago starch and water used. The optimum formulation was obtained in the model formulated with 2: 1.01: 1 minced fish: sago starch: water, respectively. The shifts in the transition temperatures values of To, Tp and Tc caused by NaCl were 16, 11.4 and 8.3oC, respectively. However, sucrose shifted the transition temperatures values of To, Tp and Tc to 29.2, 23.4 and 11.3oC, respectively. Sucrose was found to be more effective in increasing the onset and conclusion temperature of gelation of the model. The actual cooking time of the control sample of the model was 180 s and the predicted cooking time of the model according to Ansari‟s equation was 195 s. The model with either added sucrose or NaCl needed more time to be cooke

Fish gelatin and its applications in selected pharmaceutical aspects as alternative source to pork gelatin

The demand for gelatin for food and pharmaceutical application is increasing because it is one of the most widely used food ingredients. Its applications in food manufacturing are very wide-ranging including enhancing the elasticity, firmness and consistency of food products. Most commercial gelatin is presently sourced from beef bone, hide and pigskin and bones. It was reported that about 41% of the gelatin produced worldwide is basically from pigskin. Fish gelatin represents one of the important types of gelatins from other sources rather than mammalian gelatins and it may thus be considered as an alternative to mammalian gelatin for use in various food and pharmaceutical applications. In the last decades, the rising interest in halal products issues for Muslim populations become one of the main reasons for exploring different types of collagen and gelatin from different animal sources. This review summarizes gelatin in four areas: (1) pig gelatin and halal issue, (3) selected methods used in fish gelatin extraction, (3) selected functional properties of fish gelatin and (4) selected pharmaceutical and medical application of fish gelatin

A review on physicochemical and thermorheological properties of sago starch

This study was a part of a research project aiming to investigate the texture characteristics of protein - starch interaction in fish based product keropok lekor. Accordingly, the current review study focused on some physicochemical (molecular weight, viscosity, chemical composition and swelling power) and thermorheological (gelatinization, retrogradation and viscoelsticity) characteristics of sago starch alone and in mixtures with other ingredients such as sucrose, salts and hydroclloids. The inferred outcome of this extensive survey revealed that the gelatinisation temperature for sago-water mixture ranged from 69.4-70.1°C which was low compared to sweet potato, tania and yam starches. The role of using hydrocolloids in starch-based foods was to control the rheological properties as well as modifying the texture of the products, enhaning or modifying the gelatinization and retrogradation behaviour and improving water-holding capacity of the system. In the presence of sucrose or sodium chloride, the gelatinisation temperatures of sago starch shifted to higher temperatures and its enthalpy decreased. The addition of salts caused an elevation or depression of gelatinization temperature and gelatinization enthalpy, depending on their types and concentrations used. However, sodium chloride appeared to exhibit a maximum inhibitory effect on starch gelatinisation at a concentration of 6-9%

Effect of some biopolymers on the rheological behavior of surimi gel

The objective of this study was to investigate the effect of selected biopolymers on the rheological properties of surimi. In our paper, we highlight the functional properties and rheological aspects of some starch mixtures used in surimi. However, the influence of some other ingredients, such as cryoprotectants, mannans, and hydroxylpropylmethylcellulose (HPMC), on the rheological properties of surimi is also described. The outcome reveals that storage modulus increased with the addition of higher levels of starch. Moreover, the increasing starch level increased the breaking force, deformation, and gel strength of surimi as a result of the absorption of water by starch granules in the mixture to make the surimi more rigid. On the other hand, the addition of cryoprotectants, mannans, and HPMC improved the rheological properties of surimi. The data obtained in this paper could be beneficial particularly to the scientists who deal with food processing field

Mixed biopolymer systems based on starch

A binary mixture of starch–starch or starch with other biopolymers such as protein and non-starch polysaccharides could provide a new approach in producing starch-based food products. In the context of food processing, a specific adjustment in the rheological properties plays an important role in regulating production processing and optimizing the applicability, stability, and sensory of the final food products. This review examines various biopolymer mixtures based on starch and the influence of their interaction on physicochemical and rheological properties of the starch-based foods. It is evident that the physicochemical and rheological characteristics of the biopolymers mixture are highly dependent on the type of starch and other biopolymers that make them up mixing ratios, mixing procedure and presence of other food ingredients in the mixture. Understanding these properties will lead to improve the formulation of starch–based foods and minimize the need to resort to chemically modified starch