Functional properties of corn and corn–lentil extrudates

Functional properties of corn and corn–lentil extrudates were investigated as a result of extrusion conditions, including feed rate (2.5–6.8 kg/h), feed moisture (13–19% wet basis) and extrusion temperature (170–230 °C). Lentil was used in mixtures with corn flour at a ratio of 10–50% (legume/corn). The water absorption index of extrudates increased with extrusion temperature and feed moisture content and decreased with feed rate and lentil/corn ratio. The water solubility index of extrudates increased with temperature, but decreased with feed moisture content and feed rate. The oil absorption index of extrudates increased with extrusion temperature and decreased with feed rate, feed moisture content and lentil/corn ratio. Generally, the use of lentil flour led to products with lower values for functional properties. Principal component analysis of functional properties discriminated samples with appropriate functionality based on industrial use.     

Functional properties of yellow field pea (Pisum sativum L.) seed flours and the in vitro bioactive properties of their polyphenols

Functional and bioactive properties of yellow field pea (Pisum sativum L) seed flour, protein isolate (PPI), two high fibre products (Centara III, Centara IV), and one high fibre–starch ingredient (Uptake 80), were determined. The whole seed flour had superior water and oil absorption capacities but the high fibre flours had significantly higher (p < 0.05) swelling ability. Centara IV and Uptake 80 had the highest gel clarity while Centara IV gel was the most resistant to freeze–thaw treatment. Polyphenolic constituents were extracted singly or sequentially with aqueous methanol and acetone; the whole pea seed flour and the pea protein isolate had significantly more polyphenolic constituents than the fibre products, which also resulted in higher in vitro antioxidant activities (trolox equivalent antioxidant capacity and diphenyl-picryl hydrazyl free radical scavenging ability). Results of renin- and ACE-inhibitory activities were mixed and did not correspond to the overall polyphenolic content and antioxidant test results, probably indicating the importance of components specific to individual extracts.     

Flavonol profile of cactus fruits (Opuntia ficus-indica) enriched cereal-based extrudates: Authenticity and impact of extrusion

In previous studies, it was hypothesized that isorhamnetin glycosides are the dominant flavonol derivatives occurring in the peels and cladodes of cactus Opuntia ficus-indica fruits and might be used as markers for analyzing the authenticity of food products containing (whole) cactus fruits or cladodes. In the present work, use of the whole yellow-orange fruit from cactus O. ficus-indica as an ingredient of rice- and corn-based snacks was evaluated. The impact of extrusion cooking on the flavonol profile was characterized in rice- and corn-based extruded products fortified with a freeze-dried preparation from the whole cactus fruit. HPLC analysis showed that the flavonol profile of cactus O. ficus-indica consisted of five prominent isorhamnetin glycosides with a concentration of 148.9 μg/100 mg dw. In contrast, the rice or corn grits used in the present study did not contain any flavonol at all. The freeze-dried fruit was added in different ratios (0, 2, 6, and 10%) to the rice or corn grits prior to the extrusion process. Analysis of the final extrusion products showed that flavonol profiles from the fortified rice or corn products, even at the lowest level of addition (2%), were similar to the original profile of the fruit before processing. Furthermore, the total flavonol content in extruded products was not significantly affected by extrusion cooking. This study showed that the unique flavonol profile of fruits from cactus O. ficus-indica might serve as a biochemical marker for the evaluation of the authenticity of products made from whole cactus fruit or the fruit's peel.     

Hull-less barley flour supplemented corn extrudates produced by conventional extrusion and CO2 injection process

The effects of feed moisture content (20, 25%), exit–die temperature (80, 130 °C), and extrusion-cooking method (with/without CO₂ injection) on β-glucan (BG) levels and physicochemical properties of hull-less barley flour (HBF) supplemented (15, 30, 45%) corn extrudates were investigated. The highest HBF supplementation level (45%) resulted in higher BG levels (2.87–3.28%) in all extrusion conditions. In general, increasing feed moisture content from 20 to 25% and exit–die temperature from 80 to 130 °C resulted in small increases in enzyme resistant starch type-3 (RS₃) levels. However, the investigated extrusion conditions did not form substantial amount of RS₃ and the highest RS₃ content was 540 mg/100 g. Lower feed moisture content and higher exit–die temperature resulted in higher water solubility (WS) and lower water-binding capacity (WBC) values. Cold-paste viscosity (CV) was observed in all extrudates. High WS and WBC values of extrudates and the existence of CV values in RVA curves indicated complete starch gelatinization.Industrial relevanceCO₂ injection has been proved as a reliable alternative method to the conventional extrusion process used in the breakfast cereals and snack food industry. The overall quality of the product processed by CO₂ injection was comparable to that of the current process. The extrudates produced by CO₂ injection method had more uniform expansion and smoother surface. CO₂ injection did not have a reducing effect on β-glucan levels; however, it is expected to result in a better retention of heat labile micronutrients and hence more healthy food products.     

Bread Making Potential of Composite Flour of Wheat-Acha (Digitaria exilis staph) Enriched with Cowpea (Vigna unguiculata L. walp) Flour

Bread-making potentials of composite flours containing 90% wheat and 10% acha enriched with 0-15% cowpea flour were investigated. Proximate composition and functional properties of the blends were studied using AOAC standard methods. Bread loaves were prepared from the blends using the straight dough method and evaluated for loaf height, loaf volume, loaf weight and sensory characteristics. Crude protein, crude fat, crude fibre and ash contents increased significantly (p < 0.05) with increase in level of cowpea flour addition, but moisture content was not significantly (p > 0.05) different among the blends. Functional properties, with exception of bulk density and swelling capacity, were significantly (p < 0.05) different among the blends. Average loaf height and loaf volume decreased significantly (p < 0.05) with increased cowpea flour but loaf weight showed opposite trend with significant (p < 0.05) differences as cowpea flour increased. However, the addition of cowpea flour significantly (p < 0.05) decreased the loaf specific volume but all enriched samples were not significantly (p > 0.05) different. Bread samples from composited blends were rated lower than bread from all wheat bread. Bread loaves from enriched composite flour with up to 10% cowpea flour were acceptable to the panelists.     

Evaluation of gastrointestinal transit in rats fed dietary fibres differing in their susceptibility to large intestine fermentation

The rate and extent of in situ digesta transit after ingestion of diets containing dietary fibres differing in their susceptibility to large intestine fermentation were investigated. One hundred and twenty rats were fed diets containing 7.5% cellulose, inulin, potato fibre or maize starch for 3 days, then the same diets with titanium dioxide (TiO₂) for 3 days, followed by diets without TiO₂ for 2 days. In all diets, TiO₂ ratios rapidly increased within 24 h and reached a maximum level in duodenum, caecum and colon within 2–3 days. Inulin, potato fibre and maize starch-fed rats showed higher levels of caecal short-chain fatty acids, lower faecal polysaccharide concentrations, and reduced faecal output than the rats fed cellulose. Inulin was highly susceptible to caecal microbial fermentation compared to the other dietary fibres. Transit of these dietary fibres through the GI tract was rapid, and the rate of digesta transit was not affected by dietary fibre fermentability in the large intestine.     

Physical and structural changes induced by high pressure on corn starch,rice flour and waxy rice flour

The impact of high pressure (HP) processing on corn starch, rice flour and waxy rice flour was investigated as a function of pressure level (400 MPa; 600 MPa), pressure holding time (5 min; 10 min), and temperature (20 °C; 40 °C). Samples were pre-conditioned (final moisture level: 40 g/100 g) before HP treatments. Both the HP treated and the untreated raw materials were evaluated for pasting properties and solvent retention capacity, and investigated by differential scanning calorimetry, X-ray diffractometry and environmental scanning electron microscopy. Different pasting behaviors and solvent retention capacities were evidenced according to the applied pressure. Corn starch presented a slower gelatinization trend when treated at 600 MPa. Corn starch and rice flour treated at 600 MPa showed a higher retention capacity of carbonate and lactic acid solvents, respectively. Differential scanning calorimetry and environmental scanning electron microscopy investigations highlighted that HP affected the starch structure of rice flour and corn starch. Few variations were evidenced in waxy rice flour. These results can assist in advancing the HP processing knowledge, as the possibility to successfully process raw samples in a very high sample-to-water concentration level was evidenced.Industrial relevanceThis work investigates the effect of high pressure as a potential technique to modify the processing characteristics of starchy materials without using high temperature. In this case the starches were processed in the powder form - and not as a slurry as in previously reported studies - showing the flexibility of the HP treatment. The relevance for industrial application is the possibility to change the structure of flour starches, and thus modifying the processability of the mentioned products.     

Ready-to-eat chickpea flour purée or cream processed by hydrostatic high pressure with final microwave heating

It was shown that high hydrostatic pressure (HHP) induces either starch gelatinization or protein aggregation in chickpea flour (CF) slurries. The aim of this work was to develop a new “ready-to-eat” semi-solid CF product by using HHP at 600 MPa and 50 °C for 15 or 25 min combined with final microwave heating prior to consumption. Eight combinations with a formulation that includes raw or toasted CF, with or without lemon juice, were evaluated using physicochemical (color and protein content, mechanical and rheological behavior), microbiological and sensory analyses. All the CF products were microbiologically safe and stable during two months at refrigerated storage. Mainly, the HHP-treated CF products differed in their texture depending on the CF used, the holding time and the presence of lemon juice, whereby each individual product could be classified as a CF purée or a cream. Moreover, all the formulations showed similar very high sensory quality.Industrial relevanceHHP at 600 MPa and 50 °C, applied for 15 or 25 min to chickpea flour (CF) slurries formulated with raw or toasted CF, water in which chickpeas had been cooked, extra virgin olive oil, soy milk, salt, and, optionally, lemon juice induced starch gelatinization (HHP-induced gelatinization) and microbiological preservation that was sustained for two months in refrigerated storage at 4 °C. After microwave heating prior to consumption, CF products with the rheology and texture characteristic of purée or cream were obtained. The development of these refrigerated gluten-free HHP-induced semi-solid CF products which can be given a quick final heating in a microwave oven would be commercially interesting and foreseeably successful, providing the catering industry and consumers with various new CF products with high protein content, thus also helping to increase consumption of pulses and their contribution to food and nutritional safety.     

Understanding high pressure-induced changes in wheat flour–water suspensions using starch–gluten mixtures as model systems

The effect of high pressure (HP) on wheat flour–water suspensions was investigated. Suspensions were treated for 10 min at 200–600 MPa. HP-treatment significantly increased the consistency of the flour suspensions, as studied by frequency sweep tests. Temperature sweeps revealed that HP-induced starch gelatinisation, with a sigmoidal-shaped correlation between degree of gelatinisation and treatment pressure. Analysis of protein solubility in different buffers indicated the HP-induced formation of urea-insoluble complexes and/or disulphide bonds. Furthermore, the effects of HP on the isolated components wheat starch and gluten were studied, and starch–gluten mixtures were used as a model system for flour. A negative effect of gluten on the consistency increase of starch suspension was observed. Comparing the rheological parameters of HP-treated wheat flour suspensions to those of starch suspensions, confirmed the weakening effect of gluten. However, the presence of gluten in flour could not fully explain the differences between starch and flour suspension.     

Cold atmospheric pressure plasma processing of insect flour from Tenebrio molitor: Impact on microbial load and quality attributes in comparison to dry heat treatment

In this study, the applicability of semi-direct cold atmospheric pressure plasma (CAPP) during postharvest processing of Tenebrio molitor flour is investigated. Besides analyzing the decontamination efficacy, plasma-induced impact on techno-functionality, protein solubility, composition and structure was determined and compared to heat induced effects.Following CAPP treatment, the total microbial load of the Tenebrio flour of 7.72 log₁₀ cfu/g was reduced to 7.10 (1 min), 6.72 (2.5 min), 5.79 (5 min), 5.19 (7.5 min), 5.21 (10 min) and 4.73 (15 min) log₁₀ cfu/g. With increasing exposure to CAPP, protein solubility at pH 4 almost linearly decreased to a minimum of 54%. Water binding capacity decreased from 0.79 to 0.64 g_water/g whereas oil binding capacity increased from 0.59 to 0.66 g_oil/g. Gel electrophoresis revealed a decrease of all protein fractions at pH 4 whereas at pH 10 the band pattern significantly shifted to protein fractions with higher molecular weights.Industrial relevanceEdible insects are rich in valuable protein, fat, fibre, minerals and micronutrients. Although a wide range of species represent a valuable alternative protein source that could contribute to food and feed security, they are industrially hardly exploited. The tailored application of proper processing technologies could lead to novel insect-based high-protein food and feed products with unique functional properties supporting the increase in acceptability among potential consumers. Current research concentrates on developing processing chains including innovative nonthermal approaches. Cold atmospheric pressure plasma (CAPP) has gained attention as an effective technology for the decontamination and modification of fresh and dry agricultural products. In the postharvest chain of edible insects, the application of CAPP could contribute to the development of safe and high-quality insect-based products in the food and feed sector.     

Jaboticaba Pomace Powder Obtained as a Co-product of Juice Extraction: A Comparative Study of Powder Obtained from Peel and Whole Fruit

This study presents the evaluation of an emergent co-product generated during the production of jaboticaba juice by steam drag: the jaboticaba pomace. A comparison of physicochemical, technological and morphological properties of the jaboticaba powders obtained from the pomace, from the whole fruit and from the peel was performed. All the powder samples underwent the same processing: freeze-drying, milling and sieving. The powders appeared reddish, with an average diameter of approximately 64.83–103.51 μm and pH values of 3.45–3.74, water activity of 0.3133–0.3270, water holding capacity of 2.63–4.28 g H₂O/g and oil holding capacity of 2.79–2.98 g oil/g. Differential scanning calorimetry analysis showed that the endothermic peak temperature was 158.9–164.4 °C. Proximate composition analysis showed a large amount of total dietary fibre and insoluble dietary fibre in jaboticaba pomace (20.54 and 16.42 g/100 g, respectively), while jaboticaba peel had a good amount of soluble dietary fibre (10.72 g/100 g). Jaboticaba pomace had a large quantity of phenolic compounds (43.39 mg GAE/g d.w.), especially monomeric anthocyanin (3.92 mg cyanidin-3-glucoside/g d.w.), compared to the whole fruit. Jaboticaba pomace is valuable due to its high phenolic content (2.5 times higher than the whole fruit) and total dietary fibre content (2.2 times higher than the whole fruit). The results obtained in this study reinforce the idea that this co-product could be re-used in the development of functional ingredients and show that the industrialisation of these materials is one possible alternative for food diversification. Pomace powder could be added to many types of foods, such as cereals, snacks, drink mixes, and breads, or could be used for pharmaceuticals, such as slow-release antioxidants in packaging films.     

Physicochemical and Sensory Properties of Instant Kunun-Zaki Flour Blends from Sorghum and Mango Mesocarp Flours

Instant Kunun-zaki, a fermented non-alcoholic sorghum beverage, was prepared by mixing different per cent blend ratios of unmalted sorghum flour: mango mesocarp flour (90:0, 75:15, 70:20, 65:25, and 60:30) with 10% malted sorghum. Proximate compositions, chemical and functional properties of the blends were analyzed. Addition of mango mesocarp flour significantly (p ≤ 0.05) increased the ash (1.31 to 1.75%), crude fibre (2.57 to 3.39%) and decreased significantly (p < 0.05) the energy content (368.21 to 354.67 kcal/100 g) of the blends. The β-carotene content also increased from 95.65 to 139.13 μg/100 g with increased mango mesocarp flour. Hygroscopicity increased significantly (p < 0.05) from 6.10 to 10.28% while viscosity of the blends decreased significantly (p < 0.05) from 1715 to 1195.46 cP. Mango mesocarp flour addition increased the ash, crude fibre and introduced β-carotene into the product.     

A new sensory tool to analyse the oral trajectory of biscuits with different fat and fibre contents

Reformulating traditional products such as biscuits can be a useful tool for providing the population with healthier snacks. However, it involves changes in the eating characteristics of the final product. This study focuses on the oral perception of these biscuits, using the Temporal Dominance of Sensation (TDS) technique with two different amounts of fat (60 g and 30 g fat/100 g flour) and fibre (4 g and 8 g fibre/100 g flour). The TDS data obtained with a trained panel showed that hardness was the first dominant attribute in all the formulations during the mastication process. The dominance of the other parameters appeared to depend more on the fat and fibre contents, as crispness appeared with high-fat biscuits and crunchiness with low-fat, high-fibre ones, whilst both attributes were perceived in intermediate formulations. In the high-fibre formulations, grittiness and dry mouthfeel appeared during chewing and dry mouthfeel was dominant. At the end of the mastication all the biscuits were perceived as pasty. A fat mouthfeel was also perceived with both high-fat and low-fat biscuits, with or without the addition of a low level of fibre. Penalty analysis based on JAR scales, showed that excessive hardness and excessive dry mouthfeel were the most penalizing sensory characteristics causing significant drop in biscuit acceptability.     

Carbohydrate composition of raw and extruded pulse flours

Extrusion cooking technology is commercially used in the fabrication of a variety of snack-type and ready-to-eat foods made from cereal grains. However, with the exception of soybean, pulses such as lentil, dry pea and chickpea have not been used for the development of extruded food products. In this study, total carbohydrates, mono-, di- and oligosaccharides, and soluble and insoluble dietary fiber were determined before and after extrusion cooking under specific processing conditions. Concentrations of total available carbohydrates (TAC) in lentil, chickpea and dry pea flours ranged from 625 g/kg to 657 g/kg dry matter. Dry pea showed the highest concentration of TAC, followed by chickpea and lentil. Extrusion processing did not significantly (p < 0.05) affect the TAC content of dry pea and lentil flours. However, extrusion processing decreased the concentration of the raffinose family of oligosaccharides (raffinose and stachyose) in pulse extrudates. Formulated pulse flours demonstrated a beneficial increase in dietary fiber. This research indicates that value-added, nutritious snacks with reduced levels of flatulence factors and higher contents of dietary fiber can be fabricated successfully by extrusion processing of formulations based on lentil, dry pea or chickpea, and represent good alternatives to traditional cereal-based snacks. Also, the commercialization of value-added, pulse-based snacks would increase pulse consumption.     

Influence of water and barley β-glucan addition on wheat dough viscoelasticity

The effects of the addition of two barley β-glucan isolates (0.2–1.0% of wheat flour), differing in molecular weight, and water (53–63% in a poor breadmaking wheat flour, cv. Dion, and 58–68% in a good breadmaking wheat flour, cv. Yekora) on the viscoelastic properties of wheat flour doughs were investigated. A response surface model (CCF) was used to evaluate the effects observed on the dynamic and creep-recovery parameters of the dough. The evaluation was done separately for each combination of β-glucan isolate (BG1 of ～10⁵ Da and BG2 of ～2 × 10⁵ Da) and flour type. Besides the contents of β-glucan and water, the molecular size of the polysaccharide and the flour quality were important determinants of the dough’s viscoelastic behavior. Compared to BG1, the higher molecular weight β-glucan (BG2) brought about major changes on all the rheological responses of the fortified doughs. The addition of appropriate levels of β-glucans and water in the poor breadmaking cultivar (Dion) doughs could yield similar viscoelastic responses to those observed by a non-fortified good breadmaking quality flour dough (Yekora).     

Fruit and vegetables liking among European elderly according to food preferences,attitudes towards food and dependency

As the population ages and dependency for food-related activities increases, it becomes crucial to better understand food expectations of elderly consumers. Fruit and vegetables (F&V) are generally appreciated by elderly people. However, few studies have investigated elderly peoples’ F&V liking, taking into account their dependency and countries’ specificities. The present study aims to identify the liking of F&V, eating styles and food selectivity depending on the country of residence and levels of dependency. A European survey was conducted with 420 elderly people delegating meal-related activities, living at home or in nursing homes. Based on general food preferences, three eating styles were identified. Results showed that F&V liking is a segmenting variable. Elderly people from the style 1 (n = 145) do not really appreciate fruits nor desserts. On the contrary, elderly people from style 2 (n = 121) are really fruit lovers. Finally, elderly people from style 3 (n = 126) liked desserts, fruits, and even more vegetables. Results showed that elderly people were nor selective towards F&V, even if there were some exceptions as exotic fruits (disliked by 19%) and fennel (disliked by 33%). Fruit and vegetables selectivity was significantly different between countries (p < 0.001), but not between men and women, or between categories (p > 0.05 in both cases). Selectivity for F&V was very variable and could reach 32 vegetables among 42 and 28 fruits among 34. The most selective participants were from Finland and the least ones, from the UK. These results can be used to design and/or adapt F&V-based products according to elderly consumers’ liking, taking into account their country of origin and their dependency.     

Effect of dietary fibre enrichment on selected properties of gluten-free bread

The enrichment of gluten-free baked products with dietary fibre seems to be necessary since it has been reported that coeliac patients have generally a low intake of fibre due to their gluten-free diet. In the present study different cereal fibres (wheat, maize, oat and barley) were added at 3, 6 and 9 g/100 g level into a gluten-free bread formulation based on corn starch, rice flour and hydroxypropyl methyl cellulose (HPMC). Doughs were evaluated based on consistency, viscosity and thermal properties. Results showed that maize and oat fibre can be added to gluten-free bread with positive impact on bread nutritional and sensory properties. All breads with 9 g/100 g fibre increased the fibre content of control by 218%, but they were rated lower than those with 3 and 6 g/100 g fibre due to their powdery taste. The formulation containing barley fibre produced loaves that had more intense color and volume comparable to the control. During storage of breads a reduction in crumb moisture content and an increase in firmness were observed. The micrographs of the crumb showed the continuous matrix between starch and maize and/or oat fibre obtaining a more aerated structure.     

Antioxidant activity of fresh and dry fruits commonly consumed in India

Epidemiological studies from other parts of the world indicate that increased consumption of fruits and vegetables are associated with lower risk of chronic degenerative diseases. Fruits are an important component of Indian diets. Studies indicate that fruits and vegetables are rich sources of phenolic compounds and antioxidant activity (AOA). Present study was taken up to determine the AOA and phenolic content of fresh and dry fruits commonly consumed in India by two different (radical scavenging) methods and relate it to their total phenolic content (TPC) for the first time. Fourteen commonly consumed fresh fruits and ten dry fruits were studied. AOA and TPC contents of both fresh and dry fruits showed marked variation. Correlation analysis between the TPC and AOA as assessed by the two methods showed that phenolics may contribute maximally to the ABTS (r = 0.84) and to lesser extent to DPPH (r = 0.77) in fresh fruits, where as in dry fruits they correlated well to DPPH activity (r = 0.97) and to a lesser extent to FRAP (r = 0.87). In general, the results indicate that majority of the fresh and dry fruits studied are rich in phenolic antioxidants with potent free radical scavenging activity imply their importance to human health.     

Inactivation of Salmonella typhimurium and Lactobacillus plantarum by UV-C light in flour powder

This research evaluates the potential use of ultraviolet C light (UV-C) as a decontamination method for powdered foods, particularly of refined flour. This technology's lethal effectiveness was evaluated on Salmonella enterica subsp. Enterica serotype Typhimurium and Lactobacillus plantarum in wheat flour, and in laboratory liquid media of different a_w and turbidities to evaluate the action mechanisms of UV-C light in powdered products. Initial results showed a large variability of lethality in flour, obtaining between 0.2 and 3.0 log₁₀ cycles of inactivation. Results obtained in laboratory media and SEM analysis of contaminated flour indicated that the variability was due to a shadow effect on the efficacy of UV-C light and not due to the low water a_w of the flour or starch content. Based on these conclusions, a 2-m vertical tunnel with twelve 480 W UV-C lamps was designed to treat flour by forming a continuous cloud of dust (0.05–2.4 kg/h). Inactivation levels of 4.0 to 1.7 log₁₀ cycles of the population of L. plantarum in flour were achieved at flow rates of 0.2 and 2.4 kg/h respectively, with a maximum residence time of 4 s.Industrial relevanceThis investigation demonstrated the lethal efficacy of the application of UV–C light to inactivate microorganisms, both pathogenic and spoilage, present in flour. 4-log10 cycles of inactivation of both Salmonella Typhimurium and Lactobacillus plantarum were inactivated with UV-C treatments. A UV-C facility was built up which enabled to treat flour in continuous conditions creating a cloud of dust with treatments of 4 s and lethalities of 4-log10 reductions.     

Stability of anthocyanins as pre-extrusion colouring of rice extrudates

The suitability of anthocyanin as a pre-extrusion colour nutraceutical of rice flour was evaluated as a function of extrusion parameters viz. moisture content, screw speed and temperature of extrusion. The retention of anthocyanin increased with an increase in the moisture content of feed material and screw speed, but decreased with an increase in the die temperature. The effect of citric acid and sodium bicarbonate on colour stability of extrudates during processing, and that of light and packaging materials during storage at ambient conditions (30 ± 2 °C) were evaluated. Addition of 1% citric acid increased the retention of anthocyanin up to 18.2% which could reduce the requirement of pre-extrusion colouring by almost 25%. Metallized polyethylene was found to be a better packaging material than low density polyethylene and protected the extrudates from light as well as losses during storage.