Polyethylene Pouches Research Articles

Fish gelatin monolayer and bilayer films incorporated with epigallocatechin gallate: Properties and their use as pouches for storage of chicken skin oil

The properties of monolayer and bilayer fish gelatin films and the corresponding films containing epigallocatechin gallate (EGCG) were examined. Bilayer films showed higher tensile strength, water vapor and light barrier properties but also higher opaqueness and yellowness than monolayer films. No differences in elongation at break and oxygen barrier property between monolayer and bilayer films were observed. Those films were used to produce pouches, in which chicken skin oil (CSO) was packaged. CSO packaged in the pouches prepared with the films containing EGCG showed lower peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and volatile compounds after 30 days of storage in comparison with that packaged in low-density polyethylene (LDPE) pouch. Additionally, at the end of the storage, linoleic acid (C18:2 n-6) and linolenic acid (C18:3 n-9) were more retained in CSO packaged in the pouches made from the films containing EGCG. Therefore, monolayer or bilayer gelatin films incorporated with EGCG could be used as packaging for oils prone to lipid oxidation.

Tendency of lipid radical formation and volatiles in lose or vacuum-packed Brazil nuts stored at room temperature or under refrigeration

The Brazil nut is an important product from the Amazonian region and its productive chain is an income source for local communities. The effect of combinations of packaging atmospheres (loose or vacuum-packed) and storage temperatures (4±1 °C or 24±2 °C) on the tendency of lipid radical formation and on volatiles was investigated for the first time in shelled Brazil nut kernels. It was observed that refrigeration, whether combined with lose packing or vacuum packing, was effective to reduce the tendency for lipid radical formation, as detected by spin-trapping electron spin resonance (ESR) spectroscopy, as well as peroxides, conjugated dienes and 3-octen-2-one. However, the combination of refrigeration with vacuum packing, even using low-density polyethylene (LDPE) pouches with a high oxygen transmission rate (OTR), also reduced the formation of hexanal, which is a major off-flavor volatile, and thus should be recommended for the storage of Brazil nut kernels for the studied period.

Quality changes of nugget prepared from fresh and smoked rainbow trout during chilled storage

Purpose The purpose of this paper is to produce fish nugget from fresh or smoked fish and to investigate the quality characteristics of fish nuggets during refrigerated storage. Design/methodology/approach The study was designed to evaluate the effect of fresh and smoked fish on the storage quality parameters of fish nuggets. The products were developed by incorporating optimum level of fresh and smoked separately and were vacuum packaged in low-density polyethylene pouches and assessed for various storage quality parameters under refrigerated (2±1°C) conditions for 27 days of storage. The products were evaluated for various chemical, microbiological and sensory parameters at regular interval of three day. Findings Nuggets from smoked fish had lower (p<0.05) moisture, higher fat and crude protein compared to fresh fish nuggets. Total volatile basic nitrogen for fresh nugget samples exceeded the limit value of 30 mg N/100 g fish muscle on the 24 days of storage. At the end of storage period, TBA values were 2.8 mg malonaldehyde/kg for fresh nugget samples and 2.1 mg malonaldehyde/kg for smoked nugget samples. Microbial counts were found to be significantly (p<0.05) higher in fresh nugget than in smoked nugget samples. Sensory quality scores of smoked nuggets were significantly higher, than fresh nugget. The shelf life of fish nugget was found to be 24 days for fresh nuggets and 27 days for smoked nugget samples according to sensory assessment results. Originality/value The paper has demonstrated that the smoked fish meat prouduce nuggets of better quality, as indicated by lower microbial counts and higher sensory attributes compared to fresh fish meat.

Volatile profile of fresh-cut ‘Rocha’ pear under various temperatures and oxygen levels

The objective of this work was to evaluate the effect of temperature and oxygen concentration on the volatile profile of packed fresh-cut 'Rocha' pear, to integrate flavor changes in the development of preservation technologies for fresh-cut fruit. Slices of 'Rocha' pear were packed in low-density polyethylene pouches, with varying fruit weight, film surface area and film thickness, and were stored at 0, 5, 10 and 15°C. After 5 days at 15°C, 8 days at 10°C and 10 days at 5 and 0°C, steady-state O2 and CO2 partial pressures were achieved and the volatile composition inside packages was measured. Samples were grouped in four classes depending on the levels of oxygen: high (>8 kPa), intermediary (8-1 kPa), low (1-0.5 kPa), and very low (<0.5 kPa, anaerobic metabolism). The acetate esters (methyl-, ethyl-, propyl-, butyl-, 2-methylbutyl-, pentyl- and hexyl-acetate) and alcohols (ethanol, butanol, 2-methyl butanol and hexanol) were analyzed for each atmosphere group. Volatile relative abundance was significantly affected by temperature and oxygen level. The levels of ethanol, the main alcohol detected, increased with temperature and oxygen depletion. Acetate esters represented 20 to 25% of the total volatiles, with butyl acetate accounting for almost 50% of the total acetate esters. Absolute levels of total acetate esters were significantly lower at 0°C than at higher temperatures, but 2-methylbutyl-, pentyl- and hexyl-acetate were significantly higher at this temperature. Decreasing oxygen levels to anaerobiose increased the total acetate esters, due to an increase in ethyl acetate, while other esters decreased. 2-Methylbutyl acetate, a flavor-important volatile in pear described as “fruity, banana, candy, citrus, peanut”, and hexyl acetate were more abundant at 0°C and oxygen levels above 8 kPa. These results suggest that the oxygen levels affect volatiles of fresh-cut pear; the design of modified atmosphere packaging should take this effect into consideration for shelf life termination.

Innovative edible packaging from mango kernel starch for the shelf life extension of red chili powder

In this study mango kernel starch (MKS) based heat sealable pouches were developed for packing of red chili powder. The films were prepared by casting technique using glycerol, sorbitol and 1:1 mixture of glycerol and sorbitol and were sealed. All films showed better heat sealing capacity but glycerol films plasticized exhibited higher seal strength than their counterparts. The red chili powder was packed in the MKS film pouches while commercially available polyethylene (PE) film was used as control. The pungency and color of red chili powder was monitored during six months storage at 40°C. The capsaicinoid content was extracted from the red chili with acetonitrile and evaluated quantitatively using spectrophotometric method. The extractable color was measured by ASTA method using acetone. The results showed significant differences in color and pungency of chili packed in MKS and PE pouches. The highest reduction in capsaicinoid content (pungency) of chili powder was observed in PE pouch (25.9%) while lowest was observed in MKS pouch containing sorbitol (15.7%). Similarly color loss was also highest in chili packed in PE pouch while lowest in MKS-sorbitol pouch.

Influence of Mono- and Multilayered Packaging Material on the Quality of Seer Fish (Scomberomorus commerson) During Chilled Storage

Consumers prefer fresh, mildly preserved fishes without added chemicals. Due to increasing awareness among consumers on health aspects, demand for fish is ever increasing. The conventional preservation methods do not offer fresh-like product for longer duration, which limits the availability of fish in distant markets. Hence, the present study was undertaken to assess the effect of mono- and multilayered packaging material on the quality of seer fish steaks during chilled storage. For this, seer fish (Scomberomorus commerson) steaks were packed in LDPE (monolayer) and polyester–polyethylene (multilayer) pouches and the packs were sealed and stored in ice. Sampling was carried out at regular intervals to assess the changes in headspace gas composition, sensory quality, biochemical, physical and microbial quality. Significant reduction in O2 and increase in CO2 content was observed for both the packs. Lower microbial counts were observed for seer fish packed in multilayered pouches as compared to LDPE. Significant (P < 0.05) lower TVB-N values were observed for seer fish packed in multilayered pouches. Reduction in TBA values and TVBN content was observed for samples packed in multilayer compared to monolayer film. No significant variation in flavor, firmness and taste was observed among the samples up to 7th day. Sensorily, seer fish steaks packed in LDPE were acceptable up to ~ 11–12 days compared to ~ 13–14 days in multilayered pouches indicating better quality in multilayered pouches.

Storage stability, color kinetics and morphology of spray-dried soursop (Annona muricata L.) powder: effect of anticaking agents

ABSTRACTSoursop is a tropical fruit that undergoes postharvest deterioration rapidly. Conversion into powder is an ave nue to value-add the fruit as it helps to reduce postharvest losses. Although powder production is not complicated, studies have shown that caking is a common problem often associated with fruit powders. Thus, an addition of a food additive is needed to improve the storage stability of powders. In this study, soursop powder was produced by spray-drying an enzyme-liquefied soursop puree incorporated with either tricalcium phosphate (TCP) or calcium silicate (CS), at three different concentrations (0.5, 1.0, and 1.5% w/w). The control was considered powder without the addition of anticaking agent. Storage stability of the powder packed in aluminum-laminated polyethylene (ALP) pouches was examined at conventional (25 ± 1°C) and accelerated (38 ± 1°C) temperatures for 91 days until lumpiness was observed. Statistical analysis showed that the addition of anticaking agent significantly (p ≤ 0.05) improved the process yield of powder (7.2%). The moisture content, water activity, density, and water solubility index of the powder were significantly affected by storage time, storage temperature, and concentration of the anticaking agents. The critical moisture content, Xc, for control and powder incorporated with either TCP or CS was 0.07 g H2O/g ds. The total color difference (ΔE) of the powder increased throughout the storage period, followed by a zero-order kinetic reaction. Kinetics-derived Arrhenius model showed that the activation energy (Ea) of color change ranged between 6.5 and 17.3 kJ/mol. Scanning electron microscopy showed that the freshly spray-dried powder was composed of spherical particles with smooth surfaces but these particles tended to agglomerate and form liquid bridges after storage for 91 days. Overall, TCP and CS exhibited a protective effect by lowering moisture adsorption and improved the glass transition temperature of the powder.

Use of high pressure technology for the development of novel jam and its quality evaluation during storage.

Jam like product was prepared using high pressure (HP) processing technology and was compared with thermally processed one for quality attributes. Strawberry pulp was mixed with pectin (1%) and sugar and packed in low density polyethylene pouches (50g pack size) and processed at 200, 400 and 600MPa for 30min at 50°C. Ascorbic acid, anthocyanins, phenolics, flavonoids and antioxidant activities were found to be significantly retained to a better extent in HP processed jams as compared to thermally processed one. The CIE L*, a* and b* values decreased significantly with increase in pressure, the decrease being of much lesser extent compared to thermally processed one. Increase in pressure was found to increase the sensory attributes for colour, appearance, flavour, texture and overall acceptability significantly; however, the scores were comparatively lesser than that of thermally processed jam. The sample processed at 600MPa showed a shelf-life of 3months on the basis of physico-chemical, sensory and microbial attributes when stored at ambient storage conditions (28±5°C).

Photo-oxidation of Pasteurized Milk in Polyethylene Pouch Packs

In the present study photo-oxidative stability of pasteurized milk packaged in polyethylenepouches was investigated. Milk packaged in three layer polyethylene pouch packs was exposed to 400,600 and 800 l´ florescent light at 4 °C for 6 days, compared with a control (stored in dark). Light had apronounced effect on fat content of milk with no effect on protein, lactose and ash content. Photo-oxidativestability of milk decreased as the intensity of light increased, peroxide value, anisidine value and conjugateddienes increased during the storage period of 6 days, higher values were observed in samples exposed to800 l´ florescent light. After 6 days of storage period, milk exposed to 400 l´ florescent light did not revealany oxidized flavour. The results of this study depicted that polyethylene pouches have the capability toresist photo-oxidation up to 400 l´ light.

Epigallocatechin-3-gallate

PurposeThe purpose of the study was to explore the possibility of utilization of epigallocatechin-3-gallate (EGCG) as a novel preservative in cheese. EGCG has strong antioxidant and antimicrobial properties and may be commercially exploited as a natural antioxidant and preservative in cheese like products which are highly susceptible to lipid oxidation.Design/methodology/approachThe study was conducted to evaluate the possibility of using EGCG as a natural antioxidant and preservative in cheese. Kalari, a hard and dry cheese, was used as a model and treated with different concentrations of EGCG (0, 0.05 and 0.10 per cent) and aerobically packaged within low-density polyethylene pouches and assessed for oxidative stability and storage quality under refrigerated (4 ± 1°C) conditions.FindingsEGCG showed a significant (p < 0.05) effect on the lipid oxidative stability as the treated products exhibited significantly (p < 0.05) lower thiobarbituric acid reactive substances (milligram malonaldehyde/kg) values. A significant (p < 0.05) effect was also observed on the microbiological characteristics of the products, as treated products showed significantly (p < 0.05) lower values for total plate count (log cfu/g), psychrophilic count (log cfu/g), yeast and mould count (log cfu/g) and free fatty acid (% oleic acid) values. Coliforms (log cfu/g) were not detected throughout the storage period. Significantly (p < 0.05) higher scores were observed for various sensory parameters of the treated products. EGCG successfully improved the oxidative stability and storage quality of Kalari.Originality/valueThe results suggest that EGCG might be useful to the dairy industry as an efficient alternative to synthetic antioxidants and preservatives.

Effect of micronization of maize grains on shelf-life of flour

The efficacy of micronization of maize (Arjun, EH-434042) in inactivating enzymes responsible for lipid degradation and extending the shelf-life of whole maize flour was evaluated. Micronization at 2008C for 4 min resulted in complete inactivation of peroxidase enzyme and reduction in lipase activity by 84%. Maize flour packaged in low density polyethylene pouches were exposed to accelerated (90% RH/388C) and ambient (65% RH/278C) storage conditions. The results indicated no significant change in free fatty acid content in micronized flour whereas a significant increase was observed in raw flour under both the storage conditions. The color and carotenoid content did not vary much during storage in both the maize flours. While micronized maize flour was stored for 60 and 120 days under accelerated and ambient conditions, respectively, without significantly affecting quality, the storage duration was only 15 and 30 days for raw maize flour under similar conditions. Practical applications Most of the thermal processing methods employed for enzyme inactivation to extend the shelflife of whole grain flour often involve longer processing time and in cases such as wet heating require additional drying to keep the moisture content at safe levels. Infrared-based micronization of grains is one novel method that combines benefits like improved starch digestibility and enhanced shelf-life. The present study on micronization of maize grain was effective in inactivating peroxidase and lipase activity and significantly reducing the formation of free fatty acids during storage. Micronization enhanced the shelf-life of whole maize flour packed in low density polyethylene pouches by fourfold when stored under ambient conditions. The outcome of this study indicates that micronization of maize grain can be effectively employed to extended the “shelf-life whole maize flour,” which otherwise is very less.

Effect of clove oil on some quality characteristics and sensory attributes of papaya pulp enriched enrobed chicken nuggets at refrigerated storage

The addition of clove oil in the broiler meat emulsion showed a significant (p<0.05) effect on some physico-chemical properties viz. pH, TBARS (thiobarbituric acid reacting substances value), FFA (free fatty acid) value and sensory attributes of chicken nuggets. The products were stored under refrigeration temperature (4±1°C), aerobically packaged in low density polyethylene pouches (LDPE) and were analyzed for some physico-chemical and sensory parameters at 0, 7, 14, 21 days. The pH value followed a gradual decreasing trend with the advancement of storage period. As the days of storage progressed TBARS and FFA values followed a significant (p<0.05) linear increasing trend. Sensory scores reduced gradually with increase in the storage days. The sensory ratings remained between fair to very good upto 14 days during the storage period. On the basis of the various sensory scores and physico-chemical parameters the product was declared spoiled on 21st day of storage period. Higher acceptability was obtained for clove oil treated which can be conveniently packed in LDPE pouches for a period of 14 days under refrigerated (4±1°C) condition.

Pomegranate (punica granatum) rind extract as an efficient alternative to synthetic preservatives in fat-rich meat products

Purpose Pomegranate rind has been reported to have strong antioxidant and antimicrobial properties. The study was conducted to evaluate the possibility of using pomegranate rind extract as an efficient alternative to synthetic antioxidants and preservatives in fat-rich meat products, which are highly susceptible to lipid oxidation. Design/methodology/approach Tabak-Maaz, a fat-rich meat product, was used as a model system and treated with different concentrations of pomegranate rind extract (0.5, 1.0 and 1.5 per cent) and aerobically packaged within low-density polyethylene pouches and assessed for lipid oxidative stability and storage quality under refrigerated (4 to 1°C) conditions. The products were evaluated for various physicochemical, microbiological and sensory parameters at regular intervals of 0, 7, 14 and 21 days. Findings Pomegranate rind extract showed a significant (p &lt; 0.05) effect on the lipid oxidative stability, as the treated products exhibited significantly (p &lt; 0.05) lower TBARS (mg malonaldehyde/kg) values. A significant (p &lt; 0.05) effect was also observed on the microbiological characteristics of the products, as treated products showed significantly lower values for microbial and yeast and mould counts and for free fatty-acid (% oleic acid) values. Sensory parameters showed significant (p &lt; 0.05) decreasing trend for both control as well as treated products throughout the period of storage; however, significantly (p &lt; 0.05) higher scores were observed for pomegranate rind extract-treated products when compared to the control. Originality/value Pomegranate rind extract successfully improved the lipid oxidative stability and storage quality of the products during refrigerated (4 ± 1°C) storage and may be commercially exploited by the meat industry as an efficient alternative without adversely affecting the sensory quality of the products.

Thermal inactivation kinetics of surface contaminating Listeria monocytogenes on vacuum-packaged agar surface and ready-to-eat sliced ham and sausage

The aim of this work was to study thermal inactivation kinetics of Listeria monocytogenes on vacuum-packaged food surfaces. The kinetics were first determined on model agar systems (BHI agar plates), mimicking cooked meat products, which have the same characteristics (pH, sodium chloride (NaCl) or sodium lactate (NaL) content and thickness) as the cooked meat products. Then, in order to validate how well the thermal inactivation on the model agar system simulated inactivation on real products, inactivation kinetics of L. monocytogenes on slices of cooked ham and cooked sausage were examined. BHI agar plates (pH6.2 or 7.2) were prepared with and without the addition of 3% NaCl or NaL. They were initially inoculated with approximately 109CFU/plate culture, aseptically packaged in linear low-density polyethylene pouches, and vacuum-sealed. Thermal treatments were performed by submerging packages in a water bath maintained at 60°C. For most of the conditions studied, the inactivation curves were linear; shoulders were only observed for curves at conditions of pH6.2 with 3.0% NaL. The t4D values (time needed to obtain an inactivation of four-log reduction) were calculated based on the best fitting models included in GInaFit. The observed t4D values for L. monocytogenes on agar surfaces ranged from 6.8 (pH6.2) to 13.7min (pH7.2 with 3.0% NaCl). At pH6.2 addition of NaCl or NaL significantly increased the heat resistance of L. monocytogenes while at pH7.2 this effect was not significant. NaL seemed to affect the heat resistance to the same extent as NaCl. Inactivation curves of L. monocytogenes on slices of cooked ham at pH6.2 with or without addition of NaCl or NaL appeared to be log-linear in shape. However, the curves obtained from cooked sausages were markedly concave and the Weibull model was used for fitting. Concerning heat resistance of L. monocytogenes on meat products, t4D values increased approximately two-fold compared to those corresponding on model agar surfaces. The addition of 3.0% NaCl and NaL in cooked ham increased t4D values of L. monocytogenes from 11.8 to 24.9min and 24.3min, respectively. Similar effects were observed on cooked sausage. Survival on the cooked sausage, containing about 33% of fat, was not significantly different from that on cooked ham. Meanwhile, the addition of NaCl or NaL decreased the average proportions of injured cells substantially. The results of this study can be used by food processors to validate thermal processes with regard to the expected inactivation of L. monocytogenes post-contaminating meat product surfaces.

Degradation kinetics of ascorbic acid in encapsulated spray-dried honey powder packaged in aluminium laminated polyethylene and high-density polyethylene

ABSTRACTThe present study evaluated the stability of nutritionally rich encapsulated spray-dried honey powders in terms of hygroscopicity, glass transition temperature, total phenolic content, antioxidant activity and ascorbic acid using maltodextrin, gum arabic, and whey protein concentrate as carriers during a storage period of 180 days using high-density polyethylene and aluminium laminated polyethylene as packaging materials at 25°C (room temperature) and 35°C (accelerated temperature). The results revealed that temperature caused a negative influence on the glass transition temperature and stability of ascorbic acid. The kinetics of ascorbic acid degradation followed a first-order reaction with a reaction rate constant dependent on temperature and packaging material. Honey powder developed with whey protein concentrate as carrier agent and stored in aluminium laminated polyethylene pouches at 35°C possessed the highest antioxidant activity and ascorbic acid due to the presence of phenolic compounds in honey, aonla (Emblica officinalis. Gaertn), and basil (Ocimum sanctum) extract. The honey powders stored in aluminium laminated polyethylene pouches showed comparatively better antioxidant properties (total phenolic content, ascorbic acid, and antioxidant activity) and minimum hygroscopicity than the powders stored in high-density polyethylene at both the storage temperatures.

Effects of Methanolic Pomegranate Peel Extract on the Chemical, Sensory, Textural, and Microbiological Properties of Gutted Rainbow Trout (Oncorhynchus mykiss) during Frozen Storage

The effects of methanolic pomegranate peel extract (MPPE) on the quality of gutted rainbow trout ( Oncorhynchus mykiss ) were examined periodically during 6 months of storage at -18°C. Fresh samples were dipped (ratio of fish to liquid, 1:2 [wt/vol]) in sterile water or in sterile water containing 1, 2, or 4% (wt/vol) MPPE and packed in low-density polyethylene pouches. The control and treated samples were analyzed monthly for microbiological, chemical, sensory, and textural characteristics. Microbial growth in samples was significantly reduced by MPPE treatment (P < 0.05). Smaller increases in the values for total volatile base nitrogen, peroxide, and thiobarbituric acid-reactive substances and better oxidative stability were also obtained. Moreover, higher organoleptic scores were recorded. However, regarding the general acceptability, the highest score was achieved in the 1% MPPE group. Greater hardness and chewiness were obtained with 4% MPPE (P < 0.05). Therefore, dipping fish in MPPE can be considered an effective method to extend the shelf life and the overall quality of the product.

Effect of thermal treatments on the storage life of pearl millet (Pennisetum glaucum) flour

Effect of pre-milling treatments, viz. roasting and hydrothermal treatment was evaluated on pearl millet [Pennisetum glaucum (L) R Br] flour stored at ambient condition (average maximum and minimum temperatures 33.1±4oC and 21.4±2oC, respectively, and 84.4±2% RH) and controlled condition (30±1oC at 50±2% RH) packed in zip-lip low density polyethylene (LDPE) pouches of 10 µm thickness having permeability 23.13g/m2 24h. Roasting and hydro thermal treatment significantly reduced fat acidity by 8% and 12%, phytic acidity by 10% and 4% and trypsin inhibitor activity by 9% and 5%, respectively, of pearl millet flour. It was observed that pearl millet flour can be stored at controlled condition in superior form than ambient condition. Storage period had significant (P&lt;0.05) effect on moisture content, fat acidity, phytic acid and trypsin inhibitors activity of pearl millet flour. It was found that untreated, roasted and hydrothermally treated pearl millet flour can be stored up to 2, 2 and 30 days at ambient conditions and 3, 3 and 45 day, respectively, at controlled condition without undue deterioration in quality.

Study of sorption behavior, shelf life and colour kinetics of vacuum puffed honey powder at accelerated storage conditions.

In the study, the storage life of vacuum puffed honey powder at accelerated storage environment (90% relative humidity and 36°C) was computed by determining the sticky-point moisture content as the critical parameter of the honey powder. The value of monolayer moisture content in the GAB model was calculated to be 0.081kg water/kg dry solids by fitting water activity and moisture sorption data. Shelf life of the honey powder was predicted to be 222days when the powder was packaged in aluminum foil-laminated polyethylene pouches with permeability value of 5.427X10(-8)kg/m(2)//day/Pa. Actual shelf life of honey powder was experimentally determined as 189days and analysis of mean relative percent derivation modulus (Rd) and root mean square (RMS) established the accuracy and acceptability of the technique for the prediction of shelf life of honey powder. Overall colour deviation pattern followed first order reaction kinetics with rate constant (k1) as 0.037day(-1). This study revealed overall colour difference of 18.1 till the end of shelf life with drastic change during initial storage period.

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Crispy nutritious papaya crackers were developed from locally available papaya and whole wheat flour by baking in oven at 130 o C for 35 min. Crackers were packed in high density polyethylene pouches and stored under ambient condition for 90 days. The influence of papaya and storage condition on physicochemical compositions was evaluated in present study. Physicochemical analyses of fresh crackers revealed the presence of moisture (3.3-3.6%), ash (4.07-4.12%), protein (6.35-8.13%), fat (1.75-1.94%), fibers (11.50-13.75%), minerals like sodium (6.1-6.61 mg/100g), magnesium (122.44115.28 mg/100g), potassium (469.62-443.34 mg/100g), calcium (24.99-21.97 mg/100g) and phosphorus (307.66-229.13 mg/100g). Among various studied physicochemical parameters only slight increases was reported in the moisture content while in case of other parameters like fat, ash, fiber, protein and mineral content some reduction was reported at the 90 days of storage. This study introduced the formulation of crackers by using whole wheat flour and papaya which can be a good source of fiber and minerals.

Effect of light emitting diode treatment on inactivation of Escherichia coli in milk

The effect of blue monochromatic light emitting diode (LED) light treatment on inactivation of Escherichia coli ATCC 25922 in milk was investigated in the present study. Wave length (405 nm–460 nm), temperature (5 °C–15 °C), and treatment time (0 min–90 min) were considered as the independent variables and log reduction of E. coli and overall colour change of the treated milk were measured as the dependent variables. It was observed that the maximum microbial reduction was achieved at higher temperatures and lower wavelengths. The optimized values of wavelength, temperature, and treatment time corresponding to log reduction value of five (pasteurization), and minimum overall colour change were 406 nm, 13.8 °C, and 37.83 min, respectively. There was no significant difference (P > 0.05) in physico-chemical properties of the LED treated milk in comparison to untreated samples. The shelf-lives of the LED treated milk samples, packaged aseptically in low density polyethylene (LDPE) pouches and stored at 37 °C and 4 °C were 19 h and 9 days, respectively. The data obtained in the research are expected to form a platform for development of a continuous LED based pasteurization system.