Characterization of cellulase immobilized by different methods of entrapment and its application for carrot juice extraction.

In the present study, cellulase has been immobilized by two different methods of entrapment viz. encapsulation in calcium alginate and matrix entrapment in agar. The calcium alginate encapsulated beads showed an immobilization efficiency of 92.11% and agar entrapped cubes showed an immobilization efficiency of 97.63%. The free cellulase was found to show optimum activity at 50 °C and pH 4, had a Km of 39.29 mg/mL, Vmax of 0.50 µmol/min. The calcium alginate encapsulated beads showed optimum activity at 50 °C, and pH 8, had a Km of 72.28 mg/mL and Vmax of 1.32 µmol/min. The agar entrapped cubes showed optimum activity at 60 °C, and pH 4, had a Km of 13.08 mg/mL, and Vmax of 0.38 µmol/min. The immobilized cellulases could be used for 5 cycles after which their activity deteriorated. The immobilized as well as the free enzyme were effective in increasing the yield of carrot juice.

Preparation and characterization of potato starch-based composite films reinforced by modified banana fibers and its application in packaging of grapes.

The current study focuses on the preparation and characterization of potato starch-based biocomposite films by reinforcing them with banana fiber. The banana fibers were modified using ultrasonication and cellulase enzyme, individually and in combination. Both native and modified banana fibers underwent physical, morphological, FTIR, and crystallinity analyses. The resulting biocomposite films, created by incorporating native and treated banana fibers, were then evaluated for their mechanical, thermal, barrier, and biodegradable properties. The findings indicated that combining ultrasound with enzyme treatment of banana fibers in the potato starch matrix led to a substantial reduction in water-sorption and water-vapor permeability (0.156 g mm m-2 h-1 kPa-1) of the packaging films. Additionally, the mechanical properties (5.02 MPa-Tensile strength, 4.27 MPa-Sealability) of the films significantly improved with the inclusion of modified banana fibers. FTIR analysis revealed similar spectra for all modified samples, along with enhanced crystallinity. Moreover, the thermal stability of the developed films was enhanced by the incorporation of modified banana fibers. Scanning electron microscopy showed that the modified fibers exhibited smooth surfaces and an even distribution of spaces compared with the native fibers. The biocomposite films demonstrated biodegradation within 42 days. Furthermore, the packaging application was tested with grapes, which showed that the films could maintain storability for up to 8 days. Overall, these results suggest a promising eco-friendly method for producing packaging films with biocompatible, biodegradable, and non-toxic properties.

Comprehensive review on single and dual modification of starch: Methods, properties and applications.

Starch is a natural, renewable, affordable, and easily available polymer used as gelling agents, thickeners, binders, and potential raw materials in various food products. Due to these techno-functional properties of starch, food and non-food industries are showing interest in developing starch-based food products such as films, hydrogels, starch nanoparticles, and many more. However, the application of native starch is limited due to its shortcomings. To overcome these problems, modification of starch is necessary. Various single and dual modification processes are used to improve techno-functional, morphological, and microstructural properties, film-forming capacity, and resistant starch. This review paper provides a comprehensive and critical understanding of physical, chemical, enzymatic, and dual modifications (combination of any two single modifications), the effects of parameters on modification, and their applications. The sequence of modification plays a key role in the dual modification process. All single modification methods modify the physicochemical properties, crystallinity, and emulsion properties, but some shortcomings such as lower thermal, acidic, and shear stability limit their application in industries. Dual modification has been introduced to overcome these limitations and maximize the effectiveness of single modification.

Application of natural extracts as active ingredient in biopolymer based packaging systems.

Active packaging systems come under novel techniques and are creating demands in food packaging aspects. They are specially designed for food products where shelf life is a key driving factor. Their wide range of functionality preserves the color, texture, smell, and taste of the food item retaining their freshness and edibility for longer than any other methods available on market. An active ingredient in packaging systems enables efficient consumable quality which resulted in reduced complaints from consumers. However, techniques must be inexpensive and environment-friendly. The use of biodegradable packaging systems reinforced by exploiting natural compounds forms the latest trend to attract consumer demand in substituting synthetic preservatives in foods that can protect against food spoilage. Natural extracts have gained commercial importance in active packaging nowadays for the delivery of safe and high-quality foods that are being employed in both fresh and processed produce. Development and use of innovative active packaging systems in varied forms are expected to increase in the future for food safety, quality, and stability. The review overviews the beneficial effects of plant acquired components in modulating product quality in packaged form for commercial aspects in the market.

Convective drying of orange pomace at different temperatures and characterization of the obtained powders.

In the present study drying of orange pomace was carried out at 50, 60 and 70 °Cand drying kinetics was evaluated. The characterization of the orange pomace powder dried at the three different temperatures was carried out. Modified page model was found to best fit the data on drying, whereas effective moisture diffusivity ranged from 3.34 × 10-10 to 1.06 × 10-9 m2/s and the activation energy obtained was 53.07 kJ/mol. The results from powder characterization showed that the chemical composition, water holding capacity and oil holding capacity were not influenced by temperature. The emulsifying activity, swelling capacity and crystallinity were improved by increasing the temperature of drying. The antioxidant capacity and vitamin C content were observed to decrease with increase in drying temperature. There were no noticeable changes in the functional groups or structure due to temperature.

Effect of dual modification sequence on physicochemical, pasting, rheological and digestibility properties of cassava starch modified by acetic acid and ultrasound.

Dual modification of cassava starch was carried out using ultrasonication and acetylation by acetic acid by altering the sequence. The results revealed that the type of modification and sequence of modification for dual modified starches significantly affected the properties of starch. The swelling decreased for all the modified starches whereas solubility decreased for ultrasonicated starches but increased for acetylated starch and dual modified starch where acetylation was done after ultrasonication. The paste viscosities of all the modified starches were found to be significantly lower compared to native starch and the lowest viscosities were observed for dual modified starch where ultrasonication was done after acetylation. The resistant starch and slowly digestible starch content of the modified starches were significantly higher than in native starch, and the type of modification and sequence of modification for dual modified starches seemed to affect the digestibility of starches.

Application of ultrasound in combination with other technologies in food processing: A review.

The use of non-thermal processing technologies has been on the surge due to ever increasing demand for highest quality convenient foods containing the natural taste & flavor and being free of chemical additives and preservatives. Among the various non-thermal processing methods, ultrasound technology has proven to be very valuable. Ultrasound processing, being used alone or in combination with other processing methods, yields significant positive results on the quality of foods, thus has been considered efficacious. Food processes performed under the action of ultrasound are believed to be affected in part by cavitation phenomenon and mass transfer enhancement. It is considered to be an emerging and promising technology and has been applied efficiently in food processing industry for several processes such as freezing, filtration, drying, separation, emulsion, sterilization, and extraction. Various researches have opined that ultrasound leads to an increase in the performance of the process and improves the quality factors of the food. The present paper will discuss the mechanical, chemical and biochemical effects produced by the propagation of high intensity ultrasonic waves through the medium. This review outlines the current knowledge about application of ultrasound in food technology including processing, preservation and extraction. In addition, the several advantages of ultrasound processing, which when combined with other different technologies (such as microwave, supercritical CO2, high pressure processing, enzymatic extraction, etc.) are being examined. These include an array of effects such as effective mixing, retention of food characteristics, faster energy and mass transfer, reduced thermal and concentration gradients, effective extraction, increased production, and efficient alternative to conventional techniques. Furthermore, the paper presents the necessary theoretical background and details of the technology, technique, and safety precautions about ultrasound.

Effect of ultrasonication on functional properties of tamarind seed protein isolates.

In the present study protein was isolated from tamarind seed powder and was subjected to ultrasonication by varying the time (15 and 30 min) and intensity (100 and 200 W) of treatment. The effect of the ultrasound treatment on the various properties like solubility, emulsifying property, foaming property, water holding capacity, oil holding capacity, particle density and molecular weight was investigated. The solubility, emulsifying property, foaming property, water holding capacity and oil holding capacity of the ultrasonically treated tamarind seed protein isolates improved after treatment and was found to increase with time or intensity of the treatment. The particle density slightly decreased after ultrasonication, but significant differences could not be observed for the different treatment conditions. The SDS-PAGE profiling did not reveal any differences in the molecular weights of the treated and untreated proteins, implying that ultrasonication did not affect the primary structure of the proteins. It can be concluded from the study that ultrasonication can be used to improve the functional properties of tamarind seed protein isolates and therefore has potential for use in various food and non-food applications.

Optimization of banana juice extraction using combination of enzymes.

Banana juice extraction was optimized using central composite rotatable design with four numerical factors was employed to design the experiments. The numerical factors were incubation temperature (30-50 °C), and incubation time (20-60 min), cellulase concentration (0-0.4 g/100 g banana) and pectinase concentration (0-0.4 g/100 g banana). The optimum condition for extraction of banana juice were incubation temperature of 36.5 °C, incubation time of 29.33 min, cellulase concentration of 0.34% and pectinase concentration of 0.35%. The corresponding values of yield, viscosity, lightness, acidity, reducing sugar content and total soluble solids at the optimum condition were 74.15%, 101.14 mPa s, 30.06, 2.72%, 171.28 mg/100 g juice and 12.10 °Brix, respectively. Response surface analysis showed that yield increased with incubation time, and cellulase and pectinase concentration, and with temperature it initially increased and then decreased. The processing parameters had an opposite effect on viscosity. Reducing sugar content was also affected by all processing parameters.

Effect of single and dual steps annealing in combination with hydroxypropylation on physicochemical, functional and rheological properties of barley starch.

Dual modification of barley starch using annealing and hydroxypropylation was carried out. The native starch was first annealed in single step and dual step. After that, hydroxypropylation of the native, single step and dual step annealed starches were performed. The properties of native and modified starches were then investigated. Relative crystallinity of the modified starches decreased with level of hydroxypropylation and increased on annealing. Swelling, solubility, freeze-thaw stability and paste viscosities increased on hydroxypropylation and decreased with annealing. Paste clarity increased on both annealing and hydroxypropylation. Freeze-thaw stability, paste clarity and final viscosity were higher for dual modified barley starches modified by combining annealing and hydroxypropylation. Rheological studies revealed pseudoplastic nature of the starches. The flow behaviour index was found to decrease with level of hydoxypropylation for native starch, but increased for the dual modified starches. Dual modification of barley starch by combining dual step annealing with hydroxypropylation significantly improved the properties of native starch.

Effect of ultrasound and enzymatic pre-treatment on yield and properties of banana juice.

Effect of ultrasound and enzymatic pre-treatments with cellulase and pectinase on yield and properties of banana juice were investigated. A two-level full factorial design was employed. The factors selected were ultrasonication time (0 and 30min), cellulase concentration (0 and 0.2%) and pectinase concentration (0 and 0.2%). The responses studied were yield, viscosity, clarity, total soluble solids (TSS) and pH. It was observed that pectinase was more effective in increasing the yield of juice compared to cellulase. Ultrasonic pre-treatment alone did not significantly increase the yield of juice. When ultrasound was combined with pre-treatment with both the enzymes maximum yield of 89.40% was obtained compared to 47.30% in the control. The viscosity of the juice decreased with addition of enzymes and with application of ultrasound. The clarity of the juice was not affected by cellulase treatment, but improved with pectinase treatment. Ultrasonication alone was found to be more effective than pectinase or cellulase treatment in improving the clarity of the juice. The TSS increased with enzymatic treatment, ultrasonication and their combination. pH was not affected by treatment type, but was found to be lower for the treated juices. Significant correlations were observed between the various responses.

Modification of foxtail millet starch by combining physical, chemical and enzymatic methods.

Modification of foxtail millet starch was carried out by heat moisture treatment (HT), acid hydrolysis (AH), enzymatic treatment (EH), Ultrasound treatment (UT) and their combinations. A total of 15 modified starches were prepared by combining the various methods and properties were compared with native starch. The solubilities of the starches modified by HT were found to decrease whereas for other single modifications it increased. It also increased with number of modifications applied. The swelling power decreased for all the modified starches and a decrease in swelling power was observed with increase in number of modifications. Freeze-thaw stability improved for starches modified by single physical modifications i.e. HT and UT. Decrease in viscosities was observed for the modified starches and was particularly affected by AH. The pasting temperature was found to increase for those modified starches where HT was carried out. The modified starches gave softer gels.

Dual modification of taro starch by microwave and other heat moisture treatments.

Effect of heat moisture treatment on the physicochemical properties of taro starch with 25% moisture (w/w) modified by single treatments of microwave (HMT1), autoclave (HMT2) and hot air oven (HMT3), and dual treatments of microwave followed by autoclave (HMT4) and microwave followed by hot air oven (HMT5) were investigated. Amylose contents of the modified starches increased except for HMT3. A loss of physical integrity of the starch granules were observed for dual modified starches. The swelling and solubility of all the modified starches increased. The peak viscosities of starches modified by HMT1 and HMT5 were found to be higher whereas for other modified starches it was lower than that of native starch. The holding and final viscosities of all the modified starches except HMT4 were higher than native starch. The freeze-thaw stabilities of the modified starches were also found to be better than that of native starch.

Effect of dual modification with hydroxypropylation and cross-linking on physicochemical properties of taro starch.

Dual modification of taro starch by hydroxypropylation and cross-linking was carried out and the properties of the modified starches were investigated. Two different levels of hydroxypropylation (5 and 10%) and cross-linking (0.05 and 0.10%) were used in different sequences. The amylose contents of the starch decreased due to single and dual modification. For the dual-modified starches, the swelling, solubility and clarity was found to increase with level of hydroxypropylation and decrease with level of cross-linking. The freeze-thaw stability of the dual-modified starches was also affected by the sequence of modification. The viscosities of the cross-linked and dual-modified starches were more than native and hydroxypropylated starches. The firmness of the dual-modified starches was also higher than native and single modified starches. The dual-modified starches have benefits of both type of modifications and could be used for specific purposes e.g. food products requiring high viscosity as well as freeze-thaw stability.

Influence of bamboo shoot powder fortification on physico-chemical, textural and organoleptic characteristics of biscuits.

Bamboo shoot has attracted significant research and a commercial interest due to its many health-promoting bioactive compounds as well as its effectiveness in decreasing blood pressure, cholesterol and increasing appetite. As availability of fresh shoot is limited due to its seasonality there is need of incorporation of nutrients of shoot to any common food product which is easily available throughout year. Shoots of Bambusa balcooa variety were taken and edible parts were separated. Slices of shoot were boiled, dried, powdered, sieved, analysed for nutritional status and used for biscuit making. Bamboo shoot powder (BSP) was added in 0 % (control), 5, 10, and 15 % level in dry ingredients by replacing wheat flour and other ingredients were kept constant. Dough prepared are firstly analysed for basic characteristics. Then biscuits were prepared and analyzed for moisture, water activity, protein, fiber, fat, ash, phenolics, antioxidant activity, dimension, hardness, color and sensory acceptability. Variations were observed for fiber, antioxidant activity and phenolics from 1.08 to 1.97 %, 3.50 to 17.85 % and 0.45 to 4.19 mg/100 g respectively. Results showed that up to 10 % fortification level the biscuits were acceptable with improved functional and neutraceutical properties compared to the control.

Optimization of starch isolation from taro using combination of enzymes and comparison of properties of starches isolated by enzymatic and conventional methods.

The optimization of enzymatic starch isolation process from taro tubers using cellulase and xylanase was carried out. The functional properties of starch isolated by optimized enzymatic process were compared with starch isolated by conventional method without the use of enzymes. A central composite rotatable design (CCRD) with four numerical factors was employed to design the experiments. The numerical factors were cellulase concentration (0-100 U/100 g tuber), xylanase concentration (0-100 U/100 g tuber), temperature of incubation (30-50 °C) and incubation time (1-5 h). Statistical analysis showed that the main effects of all the factors were significant on starch yield and effect of cellulase was more significant compared to xylanase. The effectiveness of xylanase in increasing the yield of starch from taro tubers confirmed that xylan is an important component of the cell walls of taro tubers. The optimized condition with maximum starch yield (17.22 %) was obtained when cellulase and xylanase concentration were 299.86 and 300 U/100 g tuber, temperature was 35 °C and incubation time was 2 h. The swelling of the starch granules increased whereas solubility decreased for enzymatic method. The clarity of the starch paste isolated by enzymatic method was found to be better compared to the clarity of starch paste isolated by conventional method. The pasting temperature of the starch paste was slightly higher and viscosity was lower for the starch isolated by enzymatic method. Freeze-thaw stability of the starch paste was also found to be better for the enzymatically isolated starch.

Pectinase production by Aspergillus niger using banana (Musa balbisiana) peel as substrate and its effect on clarification of banana juice.

Optimization of substrate concentration, time of incubation and temperature for crude pectinase production from A. niger was carried out using Bhimkol banana (Musa balbisiana) peel as substrate. The crude pectinase produced was partially purified using ethanol and effectiveness of crude and partially purified pectinase was studied for banana juice clarification. The optimum substrate concentration, incubation time and temperature of incubation were 8.07 %, 65.82 h and 32.37 °C respectively, and the polygalacturonase (PG) activity achieved was 6.6 U/ml for crude pectinase. The partially purified enzyme showed more than 3 times of polygalacturonase activity as compared to the crude enzyme. The SDS-PAGE profile showed that the molecular weight of proteins present in the different pectinases varied from 34 to 42 kDa. The study further revealed that highest clarification was achieved when raw banana juice was incubated for 60 min with 2 % concentration of partially purified pectinase and the absorbance obtained was 0.10.

Effect of enzyme concentration, addition of water and incubation time on increase in yield of starch from potato.

Enzymatic treatment process for starch extraction from potato was investigated using cellulase enzyme and compared with conventional process. The effects of three parameters, cellulase enzyme concentration, incubation time and addition of water were evaluated for increase in starch yield as compared to the conventional process i.e., without using enzyme. A two-level full factorial design was used to study the process. The results indicated that all the main parameters and their interactions are statistically significant. Enzyme concentration and incubation time had a positive effect on the increase in starch yield while addition of water had a negative effect. The increase in starch yield ranged from 1.9% at low enzyme concentration and incubation time and high addition of water to a maximum of 70% increase from conventional process in starch yield was achieved when enzyme concentration and incubation time were high and addition of water was low suggesting water present in the ground potato meal is sufficient for access to the enzyme with in the slurry ensuring adequate contact with the substrate.