Low-density Polyethylene Pouches Research Articles

An Exploratory Analysis of the Stability and Quality of Instant Soup Mix Powder Incorporated with Malabar Spinach Leaves Powder under Refrigerated Conditions

The study was carried out for determining of the shelf life of the instant soup mix powder prepared using dried Malabar spinach leaves powder, tomato powder, moong dal powder and other main ingredients. Malabar spinach Instant soup mix powder formulated with 4 g of Malabar spinach leaves powder (MSLP), 20 g of moong dal powder (MDP), and 11 g of tomato powder (TP) along with other ingredients was liked extremely by 26.66 per cent of panel members, 60 per cent panellist liked it very much, and 13.33 per cent of panel members was liked it moderately after control treatment T0 (TP: MDP, 13:22g and 0g MSLP). The samples of instant soup mixes were packed into low density polyethylene (LDPE) and were analyzed periodically for change in quality. During 90 days of storage, there was a slight increase in the moisture content of the instant soup mix powder. In control instant soup mix powder (TP: MDP, 13:22g and 0g MSLP), moisture was initially 3.37 per cent which gradually increased to 3.46 per cent at the end of the period. The moisture content of the Malabar spinach instant soup mix powder for treatments T1, T2, T3, and T4 increased incrementally, following the same pattern. This finding was consistent across all treatments, indicating a clear trend. Total plate count indicates absence of microbial load during the storage period. The results of this investigation suggested that instant soup mixes could be kept in LDPE pouches at refrigerated temperature for ninety days without experiencing any quality deterioration.

Shelf-Stability of Kiln- and Liquid-Smoked Inulin-Fortified Emulsion-Type Pangasius Mince Sausage at Refrigerated Temperature.

The objective of this study was to investigate the effects of the kiln (SK-S) and liquid smoking (LS-S) processes on the quality of inulin-fortified emulsion-type Pangasius mince sausages. The moisture content during the storage significantly (p < 0.05) decreased in C-S (control) sausages and increased (p < 0.05) in SK-S and LS-S sausages. The protein content decreased (p < 0.05) in C-S, SK-S, and LS-S throughout the storage period. Initially, among the three processed sausages, LS-S showed a lower pH value, and as the days of storage progressed, all the treatments exhibited a declining trend (p < 0.05). A significant (p < 0.05) increase in the PV was observed in all the sausages during the storage days at 5 ± 1 °C, but the intensity of the increase was lower in SK-S and LS-S. The total viable count of C-S and SK-S sausages reached the limit of acceptability (6 log10cfu g-1) on the 20th day and on the 24th day of storage. The electrophoretic protein pattern of LS-S samples exhibited retention of all bands, indicating the lower proteolysis of MHC, actin, and troponin T in comparison with other treatments. The hardness (p < 0.05) and cohesiveness (p > 0.05) values of both SK-S and LS-S reduced as the storage days progressed. The present study indicates that the emulsion-type Pangasius sausages incorporated with inulin powder (2%) exposed to kiln smoking and commercial liquid smoking retained good-to-better sensory attributes up to day 16 (C-S) and day 20 (SK-S and LS-S) under refrigerated storage at 5 ± 1 °C in low-density vacuum polyethylene (LDPE) pouches.

Effect of packaging materials on the bioactive compounds, antioxidant activity, and shelf life of germinated brown rice during storage

AbstractBackground and ObjectivesGerminated brown rice (GBR) has been proposed as a strategy to alleviate chronic disorders by delivering nutrients and biologically active substances; therefore, appropriate packaging materials and storage are necessary to preserve these bioactive phytochemicals. In this research, we investigated the bioactive compounds, antioxidant activities, and microbial load of GBR and ungerminated brown rice stored in low‐density polyethylene (LDPE) and linear low‐density polyethylene (LLDPE) pouches for a period of 9 months.FindingsThe storage of GBR samples packed in LDPE and LLDPE was evaluated in terms of changes in the moisture content (MC), water activity (aw), color (L* value), bioactive components, antioxidant activities, and microbial growth. The MC, aw, and L* values of GBR increased with prolonged storage, with a slower increase observed in samples packed in LLDPE (from 9.47% to 10.94%, from 0.394% to 0.507%, and from 59.24% to 70.68%, respectively). The bioactive components, including γ‐aminobutyric acid (GABA), γ‐oryzanol, niacin, and total phenolic contents, decreased in both packaging materials, but the decrease was minimum in samples packed in LLDPE (from 48.18 to 37.72 mg/100 g, from 72.73 to 63.92 mg/100 g, from 4.14% to 3.67%, and from 87.60% to 78.69%, respectively). The antioxidant activities of GBR were preserved when packed in LLDPE pouches stored under ambient conditions. 1,1‐Diphenyl‐2‐picrylhydrazyl increased from 83.11 to 71.85 μmol TE/100 g and ferric‐reducing antioxidant power decreased from 16.28 to 10.67 μmol trolox equivalents (TE)/100 g, respectively, in GBR samples packed in LLDPE. The increase in free fatty acids and the total plate count was more rapid in samples packed in LDPE (0.24–0.46 mg KOH/100 g and 0.00–1.04 colony‐forming unit (CFU)/g, respectively), whereas the increase was effectively delayed in samples packed in LLDPE (0.24–0.37 mg KOH/100 g and 0.00–0.71 CFU/g, respectively).ConclusionIn the present study, it is concluded that the use of LLDPE as a packaging material for GBR could significantly retain its biologically active components and delay the deterioration of its quality during storage.Significance and NoveltyProper storage is crucial for maintaining the quality of rice from harvest to consumption, and the use of LDPE and LLDPE pouches as packaging materials for GBR presents a novel approach that has not been extensively explored. The results of the current study demonstrate that storage of GBR in LLDPE pouches proved to be a highly effective method for preserving the valuable biologically active components, highlighting the potential of this packaging material for extending the shelf life and maintaining the nutritional value of GBR.

High-energy cookies for undernourished adolescents: In vivo rat assay of protein quality and evaluation of storage conditions on cookies shelf-life

The present investigation studied the protein quality of cookies developed for undernourished adolescents, following the storage stability of the cookies in different packaging materials and storage conditions. A total of 18 Sprague Dawley rats were divided into three groups (G1, G2, and G3) and each group was fed with a control diet, protein-free diet and cookies for 28 days, respectively. The Biological Value (BV), Net Protein Utilization (NPU), Protein Efficiency Ratio (PER) and True Protein Digestibility (TPD) were calculated. The developed cookies were packed and sealed in sterile Low-density polyethylene(LDPE) pouches and Metalized Polyester (M-PET) pouches. The packed cookies were stored at ambient conditions (24–27 ºC; 70–75% relative humidity (RH)) and accelerated conditions (37 ºC and 90% RH) for 90 days and analyzed for water activity, moisture content, color, texture, lipid oxidation and amino acid analysis. G3 groups provided with high-energy cookies recorded higher digestibility values and better PER, indicating that the product has better digestibility and good quality of protein and improves the growth of undernourished adolescents. Developed cookies packed in M-PET pouches under ambient conditions showed more effective quality retention with good texture, less lipid oxidation, better color and amino acid.

Effect of packaging on quality attributes of functional cookies during storage

Bamboo shoot is a functional food due to the presence of biochemical components. Therefore, there exists a great opportunity especially, for the preparation of bamboo shoot powder and its utilization in food products as a therapeutic agent. The bamboo shoot powder and extracted bamboo dietary fiber were incorporated in cookies at 0% (Cookies with 100% refined wheat flour), 2%, 4%, 6%, 8%, and 10% level by supplementing refined wheat flour. The prepared cookies with different treatments were evaluated for sensory attributes. The treatment with the highest sensory scores was packed in low-density polyethylene (LDPE) pouches and polyethylene terephthalate (PET) jars. Changes in chemical (moisture, water activity, ash, crude fat, crude protein, total carbohydrate, and total dietary fiber) and sensory scores (appearance, texture, aroma, taste, and overall acceptability) of cookies were monitored during storage (17°C and 54% relative humidity for 90 days). Although, the cookies supplemented with 6% and 8% bamboo shoot powder and dietary fiber, respectively, can be stored in LDPE pouches and PET jars up to 90 days under ambient conditions, the quality retention was better in PET jars with minimal changes in quality.

Ascertaining the refrigerated storage life of wheat bran and grape seed extract enriched meatballs (Goshtaba) under aerobic conditions

Three types of meatballs (Goshtaba) viz. control, dietary fiber (8% hydrated wheat bran) rich and anti-oxidant rich (0.1% grape seed extract) Goshtaba were prepared from good quality mutton, packaged in low density polyethylene pouches (LDPE-200µm gauge) and analyzed during its refrigerated storage (4±1◦C) to ascertain their aerobic refrigerated storage life. The emulsion stability and cooking yield of the dietary fiber rich product was improved. The pH of dietary fiber rich product increased significantly (P≤0.05), while as that of antioxidant rich Goshtaba decreased significantly (P≤0.05) with the increase in the storage period. The water activity of all the samples showed an increasing trend over the storage period. The microbial parameters (total plate count, psychrophilic count) increased during the storage period, but the values were decreased in the product fortified with grape seed extract (GSE), depicting an anti-microbial effect of GSE. The sensory quality was decreased in all the products with increase in storage life, but the rate of decline was slowest in GSE treated meatballs. It was concluded that the product treated with GSE as anti-oxidant source retained most of the desirable properties during the aerobic refrigerated storage for at least 26 days as against 17 days in case of other products.

Shelf-Life of Bunched Carrots as Affected by Nitrogen Fertilization and Leaf Presence

Nitrogen (N) fertilization is essential for adequate earliness and the commercial attractiveness of carrots, but its excess could generate fast decay during postharvest, mostly in bunched carrots exhibiting their highly perishable leaves. A field experiment was conducted over the 2016–2017 growing season to address the effects of two N fertilization rates (120 and 240 kg N ha−1, hereafter N120 and N240, respectively) and leaf presence/absence (leaf+ and leaf−) on physicochemical and compositional traits of carrots cv. ‘Dordogne’, after storage at 4.0 ± 0.5 °C, 95–96% relative humidity (RH) for 0, 3, 6, 12, and 24 days (hereafter S0–S24). Before storage, carrots were arranged in bunches and packaged in common low-density polyethylene (LDPE) pouches (thickness 95 μm), 54 × 24 cm size, with 16 holes of 5 mm size. N240 carrots compared to N120 showed higher cumulative weight loss (CWL) and firmness reduction, with differences at S24 equal to 108 vs. 41 g kg−1 fresh weight (FW) and 13.3 vs. 14.5 N, respectively. N240 compared to N120 increased also the color deviation (ΔE*ab, +126%) and nitrates content (+93%) of carrots and slowed down their temporal increase of total polyphenols and antioxidant activity. Leaf+ carrots compared to leaf boosted CWL and firmness reduction, with differences at S24 equal to 90 vs. 58 g kg−1 FW and 12 vs. 17 N, respectively. In addition, leaf presence increased reducing sugars (+17%) and decreased nitrates (−24%) contents. This research has shown the possibility of improving the desirable quality and shelf-life of carrots by halving the N dose commonly supplied by growers and marketing bunched carrots within 12 days from the start of storage.

Impact of Storage and Packaging Material on the Nutritional, Product Properties and Microbial Count of Extruded Snacks

Background:The extrusion cooking is the most widely used process so the development and consumption of extruded snack products having health and nutritious benefits would help increase the health status of the population.Objective:The aim of this study was to investigate the effect of storage days on physical, microbial activity and sensory characteristics of extruded snacks and kinetics of extruded snacks.Methods:Extruded snacks were produced by extrusion cooking at optimized conditions of temperature, moisture and screw speed of 110°C, 12% (db) and 200 rpm. The products were packed in lowdensity polyethylene (LDPE) and laminated pouches (LP) and were stored at an accelerated temperature condition of 40 ± 2°C. The storage stability in terms of quality parameters such as moisture, hardness, bulk density, color, lateral expansion, sensory characteristics and total plate count was investigated.Results:An increase (p≤0.05) in the value of moisture, bulk density, a*, and total plate count was observed during the storage period, whereas hardness, L*, b*, ΔE and sensory characteristics showed significant (p≤0.05) decreased order with storage period. No significant effect on the lateral expansion of the extruded product was observed. A significant decrease in total carbohydrate, fat and protein content was found during the storage period. The average sensory score and microbial analysis suggested that extruded snacks packed in LDPE pouches can only be acceptable up to the 60th day and extruded snacks packed in LP can be acceptable to more than 90th day. The kinetics of color and hardness suggest first order kinetics.Conclusion:Overall investigation suggested that extruded snacks were more stable in the LP as compared to LDPE pouches.

Storage stability and characterization of biochemical, rehydration and colour characteristics of dehydrated sweet corn kernels

The degradation kinetics of dehydrated sweet corn for total sugar, ascorbic acid, TSS, pH, rehydration parameters, colour and moisture content using low density polyethylene pouches (LDPE) and laminated aluminium foil pouches (LAFP) with or without vacuum were studied. The samples were kept for 3 months and were analysed at every 15 days. During the storage, total sugar, ascorbic acid and total soluble solids reduced from 10.50 to 9.73 g/100 g, 9.36 to 8.86 mg/100 g, 83 to 51°Brix respectively. Rehydration coefficient and rehydration ratio reduced from 90.28 to 75.27, 2.64 to 1.56. Colour L∗ value, a∗ value. b∗ value changed from 61.00 to 70.13, 42.93 to 53.27, 55.58 to 64.24 respectively resulting in increase in ΔE value and chroma value up to 16.29, 70.23 to 83.45 respectively. The moisture content increased from 2.12 to 3.92% in packages. The average sensory score of 7.86 even after 90 days of storage in laminated aluminium foil pouch with vacuum indicates that the product may be stored for 90 days satisfactorily. Zero and first order models fitted well and can be used for predicting various properties of dehydrated sweet corn during storage.

Assessment of Physical and Microbiological Characteristics of Quail Meat During Storage

Analysis of physical and microbiological quality of quail meat samples was carried out during frozen storage (-18±2oC) of 90 days period. Slaughtering of six weeks old broiler quails was done hygienically. Quail meat samples were packed in low density polyethylene pouches taking best possible care to avoid contamination and stored at -18 ± 2°C for 90 days. These stored samples were evaluated for physical properties and microbiological quality after thawing at 4 ± 1oC for 12 h at an interval of 15, 30, 60 and 90 days. It was observed that drip loss increased, while the extract release volume (ERV) decreased with progression of the storage period. Similarly standard plate count, Escherichia coli, Staphylococcus aureus and psychrophilic count decreased with advancement of frozen storage period. While all of the meat samples were found to be negative for Salmonella spp. It is concluded from the study that quail meat can be safely stored in frozen state for up to 3 months without any deterioration.

Shelf life assessment of natural antioxidant-treated milk smoothies stored under refrigeration at 4 ± 2°C

PurposeThis paper aims to assess the effect of natural antioxidants (Tulsi, Lemon grass and Aloevera) on sensory and microbiological quality as well as on Thiobarbituric acid (TBA) values of Redplum and Sahiwal-based milk smoothies stored under refrigeration.Design/methodology/approachThe smoothies were developed by incorporating optimum level of natural antioxidants, fresh red plum and Sahiwal milk. They were aerobically packaged in low-density polyethylene pouches and stored under refrigeration (4 ± 2°C) till its spoilage. These smoothies were assessed for various storage quality parameters like sensory parameters, microbiological quality and TBA values at regular interval of two days.FindingsSmoothies made without using natural antioxidants were in good condition for four days, and treated smoothies were stored well for six days. The microbial profile showed significant (p < 0.05) increase in SPC and psychrophilic counts on advancement of storage days. However, no coliform and yeast and mould were detected in all variants of smoothies during storage. TBA values were also increased during storage. But microbial counts and TBA both were under the prescribed limit as described by various organizations. Smoothies treated with Tulsi were found best followed by lemongrass- and aloevera-treated products.Research limitations/implicationsAmino acid and fatty acid profiling may be incorporated to known how the exact nutritional value.Practical implicationsDeveloped milk smoothies using natural antioxidants may serve the purpose of functional food.Social implicationsAs per the authors, today, world is seeking for health providing components with longer product shelf life. Therefore, the product may serve the purpose.Originality/valueThe paper has demonstrated that the Sahiwal milk and red plum-based smoothies were of high acceptability. Their shelf life was found best when treated with Tulsi, Lemon grass and Aloevera natural antioxidants. It was better in all spectrums like lower microbial counts, higher sensory attributes and lower TBA counts as compared to untreated products.

A Comparative Study of Suitability of Low-Density Polyethylene and Coextruded Laminate Pouches for Storage Stability and Shelf Life Prediction of Instant Puran Powder

Puran is a stuffing of puran poli (sweet flat bread)—an Indian traditional cuisine made from a mixture of cooked chickpea splits and jaggery. The shelf life of puran and puran poli is just 2 days under ambient conditions which guarantors the intervention of packaging studies for the product. This work is the first-ever report on the packaging and shelf life study of puran powder to the best of our knowledge. In this work, instant puran powder (IPP) by vacuum drying (at 60 °C) was prepared to reduce the processing time of puran poli, while increasing its storability. IPP was packed in low-density polyethylene (LDPE) and coextruded laminate (CL) pouches. Shelf life prediction was done using the developed kinetic models based on moisture content and water activity. Accelerated storage study of IPP samples was conducted at 38 ± 2 °C and 90 ± 2% relative humidity (RH) over a 4-month period. The IPP packed in LDPE showed significant (p < 0.05) increase in adsorbed moisture, water activity, total color difference and browning index throughout the storage period in both the storage conditions. On the other hand, the IPP packed in CL pouches which were stored at 28 °C ± 2 °C and 75% RH was stable and acceptable throughout the storage period. The predicted shelf life of IPP packed in LDPE and CL pouches were 2.42 months and 13.41 months, respectively. The study clearly suggests that CL packing is more suitable for storage of IPP.

Determination of Keeping Quality of Tea using Silica Desiccant

A study was carried out to find out the effect of silica gel on keeping quality of tea. CTC-SRD grade teas each at 250 g were packed in low density poly ethylene pouches with a small pouch containing silica gel (10 g). Another set of samples were packed in low density poly ethylene packing material without silica gel. From sealed pouches, every month one pouch was taken and analysed for their moisture and quality parameters such as theaflavin, thearubigin, high polymerised substance, total liquor colour and biochemical parameters such as total polyphenol, total catechin, water extract and amino acid. Studies conducted after fourteen month indicated that the moisture content increased in teas packed in LDPE alone and it was less in teas packed in LDPE with silica gel. The level of theaflavin content decreased by 24.01% in teas packed LDPE alone and 17.92 % in LDPE with silica gel respectively. Bio chemical parameters decreased in teas packed in LDPE when compared to LDPE with silica gel. The study reveals that silica gel is useful in maintaining the keeping quality of tea.

Enhancement of vitamin D2 stability in fortified milk during light exposure and commercial heat treatments by complexation with milk proteins

In India, changes in the life style pattern together with low consumption of vitamin D rich foods resulted in 50–90% of population as vitamin D deficient. Fortification is the common practice followed to overcome such micronutrient deficiencies. Vitamin D is fat soluble in nature and simultaneously sensitive to light and heat, however binding to milk protein improves the solubility and stability towards heat and light. Sodium caseinate, succinylated sodium caseinate (SNaCas), reassembled sodium caseinate (RNaCas) and reassembled succinylated sodium caseinate (RSNaCas) were complexed with ergocalciferol (vitamin D2). Milk protein-vitamin D2 complexes (NaCas-VD, SNaCas-VD, RNaCas-VD and RSNaCas-VD) and free vitamin D2 (free-VD) showed highest stability when stored at −20 °C, followed by 4 °C and 37 °C. At the end of storage period of 48 h, the stability (%) of vitamin D2 in milk protein-vitamin D2 complex and free vitamin D2 (free-VD) fortified milk was significantly higher (p < 0.05) in fortified samples stored in transparent glass bottles (upto 53.88%) as compared to samples stored in low density polyethylene (LDPE) pouches (upto 49.56%) upon exposure to different light intensities (1485, 2970, 4455 lux). Complexation of vitamin D2 with milk protein provided greater stability to withstand the heat treatments (pasteurization, boiling and sterilization). Stability of vitamin D was greater from milk protein-vitamin D2 fortified milk stored in transparent glass bottles than the fortified milk stored in LDPE pouches.

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&lt;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&lt;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.

Thermodynamics of sorption isotherms and storage stability of spray dried sweetened yoghurt powder.

Sorption isotherm is a quantitative approach to predict the shelf life of dried foods. Adsorption isotherms of spray dried sweetened yoghurt powder (SYP) were determined by static gravimetric technique at 20, 30, 40 and 50°C. The data obtained were fitted to eight different sorption models. A non-linear least square regression analysis was adopted to evaluate the model constants. The experimental sorption data were best fitted to four parameter Peleg model. The monolayer moisture contents found from GAB model were 4.88, 4.54, 3.86 and 3.52% at 20, 30, 40 and 50°C, respectively. The maximum net isosteric heat of sorption and sorption entropy of SYP were 9.399kJ/mol and 20.28J/molK, respectively. The Gibb's free energy change for sorption was in the range 3436.19-303.91J/mol. The storage stability in terms of moisture content, thiobarbituric acid, free fatty acid, hydroxymethyl furfural values and starter counts of SYP packed in aluminium laminated polyethylene (ALPE) and low density polyethylene (LDPE) were studied along with their change kinetics. The relationship between the water vapour permeability of packaging materials and adsorbed moisture (determined from GAB equation) in powder was used to predict the shelf life and was predicted as 28 and 44.44days in LDPE and ALPE pouches, respectively.

Effect of Walnut (Juglans regia) on Physico-chemical, Sensory and Storage Quality of Chevon Nuggets

The present study was undertaken to evaluate the possibl utilization of walnuts in the development of value added healthier chevon&nbsp; nuggets and to study their physico-chemical, sensory and storage properties. Four different levels of walnuts (Juglans regia) (0, 5, 10 and&nbsp; 15%) were selected to replace lean meat in the chevon nugget formulation. The chevon nuggets developed were analysed for various&nbsp; physicochemical and sensory parameters. Based on various parameters viz. physicochemical and sensory parameters a 10% level of wal&nbsp;nuts was adjudged as optimum for the preparation of walnut enriched chevon nuggets. Based on this study, chevon nuggets containing&nbsp; 10% levels of walnut was further studied for its storage quality. The optimized nuggets were aerobically packaged in low density poly ethylene pouches with density value of 0.930 g/cm3 along with control (0% levels of walnut) and evaluated for storage stability (physic ochemical, microbiological and sensory parameters) for 21 days under refrigerated condition (4±1oC). Both walnut enriched optimized&nbsp; nuggets and control were successfully stored for 7 days under refrigerated conditions (4±1oC) without marked loss in storage quality.&nbsp

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).