Effect Of Different Pretreatments Research Articles

Insight into Low-Temperature One-Step Biopreparation and Natural Dyeing of Cotton as an Environmentally Benign Route

AbstractThe goal of this study is to present an environmentally benign route for cotton fabric and investigate the effect of different pretreatments in natural dyeing. In this context, conventional alkaline scouring, conventional hydrogen peroxide bleaching, low-temperature one-step biopreparation processes, namely enzymatic scouring (alkaline pectinase and alkaline pectinase-neutral cellulase combination) at 55 °C and enzyme-bleaching agent (hydrogen peroxide/sodium percarbonate/sodium perborate)-activator agent (TAED) combinations at 65 °C were applied to 100% cotton knitted fabric. The use of agricultural waste and eco-friendly mordants was preferred in natural dyeing. For this purpose, pretreated fabrics were dyed with the outer green shell of almond fruit extracts and a low amount of 0.4 g/L metal mordants (alum and iron(II) sulfate) in accordance with the simultaneous mordanting method. The dyeing properties of bio- and conventionally prepared cotton fabrics were examined in terms of colorimetric data (K/S, CIELa*b*C*h°) and wash fastness compared with water absorbency, whiteness, weight loss, pectin removal, and type of mordant. Excellent wash fastness values were achieved regardless of the type of pretreatment. Low-temperature one-step biopreparation can be a good substitute for conventional scouring and bleaching processes. Since different results can be achieved, it is essential to determine and evaluate all bioprocess conditions depending on the end-use characteristics of the textile (e.g. whether it will be white or dyed/printed, its color and lightness/darkness) at the laboratory and industrial scale applications.

Effect of different pretreatments on the hydrolysis efficiency and flavor of squid viscera (Dosidicus gigas)

In order to better utilize the proteins in squid viscera (Dosidicus gigas), the effects of different pretreatments on the degree of hydrolysis (DH) and volatile compounds of hydrolysates were studied. The DH was used as an indicator to select alkaline protease as the optimal protease from 8 types of proteases. The hydrolysis conditions of alkaline protease and the flavor of the hydrolysates were investigated through single-factor, response surface methodology, and pretreatment-assisted hydrolysis experiments. The results showed that alkaline protease had the highest DH (42.08 ± 0.58%), with enzyme dosage of 1.5%, hydrolysis temperature of 45 °C, hydrolysis time of 5 h, and liquid-solid ratio of 4:1. The DH of the ultrasound group was significantly higher than other groups, with the highest DH (45.67 ± 0.34%) after ultrasound for 40 min (U40). The proportion of molecular weight < 1 kDa and the content of free amino acids (1613.64 mg/100 g) were the highest at U40. The electronic nose results indicated that the composition of organic sulfur and aliphatic compounds in U40 showed significant differences compared to other products. The U40 sample had the highest type and content of volatile compounds (especially benzaldehyde), which was more conducive to the volatilization of flavor substances. In conclusion, U40 pretreatment can effectively improve the DH and flavor of hydrolysates.

Improvement of the drying quality of blueberries by catalytic infrared blanching combined with ultrasound pretreatment

This paper investigated the effect of catalytic infrared blanching combined with ultrasound pretreatment on quality and waxy structure of blueberries. Different blueberry samples were prepared, including control (untreated) and samples treated by hot water blanching (HB), catalytic infrared blanching (CIB), ultrasound-catalytic infrared blanching (US-CIB), and catalytic infrared blanching-ultrasound (CIB-US). The effect of different pretreatments on the microstructure of blueberry epidermis was studied. The drying time of blueberries after HB, US-CIB, and CIB-US was decreased by 11.61%, 17.54%, and 17.27%, respectively, compared with control (33.75 h), and drying efficiency was significantly improved. Blueberries after pretreatments had higher content of polyphenol and anthocyanin, with an increase of 29.51–44.21% in phenol and 8.81–20.80% in anthocyanin, the antioxidant capacity of blueberries was also better than control and CIB enhanced the antioxidant capacity of blueberries. CIB-US can be used as an efficient pretreatment method for blueberry drying.

Seed dormancy and after-ripening requirements of Indian lac tree (Schleichera oleosa Lour. Oken)

ABSTRACT After-ripening (AR) is a time and environmental regulated process which determines the germination potential of the dry seeds. The after-ripened seeds swell after absorbing water and initiates metabolic activity linked to the germination process. Such after-ripening process is not studied in detail in Schleichera oleosa species. Therefore, an experiment was designed to assess the effect of different pretreatments on seed dormancy and AR patterns in the seeds of S. oleosa. The seeds were subjected to various pre-treatments, viz., mechanical scarification, scarification + Gibberellic acid (GA3, 0.02% and 0.05%), scarification + KNO3 (0.02% and 0.05%) for 24 hours. Further, the seeds were desiccated at four levels (10, 12, 14 and 16%) of intact seed water content (SWC) and were kept at either uncontrolled ambient room temperature or controlled constant temperatures (22°C, 25°C and 28°C), and their germination was tested fortnightly for 60 days. The results revealed that S. oleosa possess combined physical+ physiological dormancy and soaking of scarified seeds in GA3 solution (0.05%) for 24 hours showed the maximum germination percentage (80.0%), vigour index (721.4), and mean germination time (6.6 days). Results also indicated that AR process under optimum conditions (25°C, 16% SWC and 60 days) can increase germination percentage up to six times (81.25%) as compared to freshly collected seeds (12.5%) in the species. These findings can be utilized for developing the seed germination protocol with the aim to devise the propagation techniques and conservation programme for the species.

Effects of different pretreatments on thin-layer drying kinetics, vitamin A retention and rehydration of orange-fleshed sweet potato slices

Orange-fleshed sweet potato (OFSP) is a bio-fortified sweet potato with a high beta-carotene content. OFSP deteriorates rapidly due to its high moisture content. Conventional air drying is one of the most common methods employed but has the disadvantage of low rates of moisture removal, hence the longer drying time, which affects the quality of the final product. Pretreatments prevent quality deterioration and hasten the drying rate. This study investigated the effects of different pretreatments on thin-layer drying kinetics and the quality of OFSP slices. Three-mm-thick OFSP slices were pretreated using three different pretreatments: lemon juice, salt solution, and hot water blanching (HWB). Pretreated slices were dried in a solar dryer. Data collection (weight, temperature, relative humidity, and solar radiation) was done at 1-hour intervals. Four mathematical models (Page, Logarithmic, Modified Page, and Henderson and Pabis) were fitted to the experimental data. Also, the quality parameters of vitamin A and rehydration were investigated. The dryer inside temperatures and relative humidity ranged from 26.93–44.53 oC and 36.87%–65.30%, respectively. The moisture content of fresh OFSP slices for both treated and untreated samples was found to be in the range of 291.55–302.24% (dry basis, db), which reduced to 25.25–35.25% (db) after drying. The drying time ranged between 11 and 13 hours. The page model was found to be the best model for untreated samples, with R2 of 0.9948, RMSE of 0.0151, and χ2 of 0.0097, while the logarithmic model best described the drying behaviour of all the pretreated samples because it had the highest values of R2 and the lowest values of RMSE and χ2. Lemon juice-pretreated samples had the best quality parameters (vitamin A retention and rehydration ratio). A maximum rehydration ratio of 1.6765 was obtained for samples pretreated with lemon juice, and a minimum rehydration ratio of 1.1390 was obtained from HWB-pretreted samples. The results, therefore, indicate that lemon juice can be used as a pretreatment for thin-layer drying of OFSP slices. Pretreatments help minimise postharvest losses associated with OFSP, thus contributing to solving food and nutrition insecurity challenges.

Microstructure and physicochemical properties: effects of different pretreatment combined with dual‐frequency ultrasound on quality of large yellow croaker (Pseudosciaena crocea) during cold storage

SummaryThe quality changes of cold‐stored (4 °C) large yellow croaker (Pseudosciaena crocea) were studied by using stable chlorine dioxide combined with dual‐frequency ultrasound assisted‐slightly acidic electrolysed water (CUSS). The results of microbial indicators demonstrated that CUSS treatment inhibited microbial growth. Moreover, CUSS treatment had lower values of pH, total volatile basic nitrogen (TVB‐N) and thiobarbituric acid (TBA), and higher immobilised water content. CUSS treatment also inhibited the degradation of inosine monophosphate, suppressed the accumulation of hypoxanthine riboside and hypoxanthine. Through the results of texture profile analysis (TPA), protein degradation, and scanning electron microscopy (SEM), CUSS treatment could effectively protect the protein structure and maintain good texture characteristics of large yellow croaker. According to microbial indexes, K‐value, and sensory analysis, compared with dual‐frequency ultrasound treatment, CUSS treatment could prolong the shelf‐life of large yellow croaker for another six days. Therefore, CUSS treatment is a potential solution to preserve large yellow croaker, improving its protein characteristics.

Structural characterization of lignin from the green pretreatments for co-producing xylo-oligosaccharides and glucose: Toward full biomass utilization

Three green non-enzymatic catalysis pretreatments (NECPs) including autohydrolysis, subcritical CO2-assisted seawater autohydrolysis, and inorganic salt catalysis were utilized to simultaneously produce xylo-oligosaccharides (XOS), glucose, and cellulolytic enzyme lignin (CEL) from sugarcane bagasse (SCB). The yield of XOS in all three NECPs was over 50 % with a competitive glucose yield of enzymatic hydrolysis. And the effects of different pretreatments on the chemical structure and composition of CEL samples were also investigated. The pretreatments significantly increased the thermal stability, yield, and purity of the CEL samples. Moreover, the net yield of lignin was 58.3 % with lignin purity was 98.9 % in the autohydrolysis system. Furthermore, there was a decrease in the molecular weight of CEL samples as the pretreatment intensity increased. And the original lignin structural units sustained less damage during the NECPs, due to the cleavage of the β-O-4 bonds dominating lignin degradation. Meanwhile, these pretreatments increased the phenolic-OH in CEL samples, making the lignin more reactive, and enhancing its subsequent modification and utilization. Collectively, the described techniques have demonstrated practical significance for the coproduction of XOS and glucose, and lignin, providing a promising strategy for full utilization of biomass.

Effect of Different Pretreatments and Air Temperatures on Drying Characteristics of Kachri (Cucumis callosus) Dried in Heat Pump Dryer

Kachri (Cucumis callosus) is an underutilized fruit of India widely found in the western part of Rajasthan during the rainy season. In this study kachri fruit slices were pretreated with different pretreatments such as hot water blanching, 0.1% w/v potassium metabisulfite (KMS) and 0.1% w/v magnesium oxide (MgO) at 800C for 3 min. Pretreated samples were dried in a heat pump dryer at 40, 50 and 600C and their drying characteristics such as moisture content, drying rate, moisture diffusivity and rehydration ratio were studied. The initial moisture content of control kachri was 893.04% (db) and for the pretreated sample, it was 906.75% (db) and the final moisture content was found 4 to 6% (db) for all the treatments. The KMS treated sample took less drying time and a higher drying rate followed by MgO, hot water blanching and control. Moisture diffusivity ranged from 1.90 × 10-07 to 8.28 × 10-07 m2/s as the temperature increased from 40 to 600C. The value of the rehydration ratio ranged from 2.1 to 5.03. It was found that both rehydration ratio and moisture diffusivity values increased with an increase in drying air temperature.

Effect of different pretreatments of Aquilaria malaccensis seeds for enhancement of germination rate

A few plant species of the Thymelaeceae family are highly valuable and demanding because they contain resinous oil in their stems, branches, and roots. From this plant, resinous oil is extracted through the distillation process. Traditionally and from the religious point of view, the oil has a higher potential in the manufacturing of perfume, incense sticks, smoke, and many other medicinal and religious purposes. It is a highly economic plant, so its conservation is very important. Aquilaria plants are propagated through seeds and the seeds are recalcitrant, i.e., they are chilling sensitive and also cannot be stored at room temperature because of their high moisture content. They are also called desiccation sensitive. Below a certain level of moisture content, their embryos become death or inviable. Conservation of germplasm in the case of recalcitrant seeds is a major issue to be solved in the current situation. Our main focus was to enhance the germination of the Aquilaria malaccensis seeds for the early development of the seedlings within a short time. Here we are applying different pretreatments of Aquilaria seeds, such as Acetone for 1 min, 2 min, and 3 min, likewise Methanol, Ethanol, hot water, acetic acid, etc for enhancing seeds germination and it was found that highest germination percentage in the treatment where seeds are soaked in 1 min acetone (70%) in comparison to the control, which shows only a 56.7% germination rate. Their germination rate was determined by regular observation for up to 2 months, and the growth curve was also prepared by calculating the weight of the seeds. The findings of the current study will help to develop a protocol for early germination as well as mass propagation within a short period of time. The results of the Aquilaria species are significantly different from each other.

Effect of different Pretreatments on Physic-chemical Properties of Cucumber Chips Fried in different Oils

Effect of different Pretreatments on Physic-chemical Properties of Cucumber Chips Fried in different Oils

Seed dormancy and germination responses of cannabis landraces to various pre-treatments

The current study evaluated the effectiveness of different pre-treatments for dormancy breaking and seed germination of five cannabis landraces. These landraces were collected from local growers in three regions of KwaZulu-Natal Province in South Africa, namely, Bergville (B), Hammersdale (H), and Ladysmith (L). Each genotype was assigned an alphabet and number based on where the seed material was collected. The five landraces were as follows, ‘B1’, ‘K1’, ‘H1’, ‘L1’, and ‘L2’. The study was conducted using various pre-treatments, including potassium nitrate (KNO3), hydrochloric acid (HCL), hot water (HW) at 70 °C, nitric acid (HNO3), dry prechilling at 10 °C, gibberellic acid (GA3), sulfuric acid (H2SO4), and water, which served as the control. Before the germination test, the seed viability of cannabis landraces was assessed using the tetrazolium chloride (TCC) test. Afterward, the seeds were germinated in Petri dishes with cotton pads moistened with distilled water for five (5) days. The study was later validated under tunnel conditions. The parameters such as germination percentage, germination rate, seedling length, and seed vigour index of the germinated seeds were then measured. The landraces, dormancy breaking treatments, and their interactions showed significant differences (p < 0.001) in germination percentage, germination rate index, seedling length, and seed vigour index under both laboratory and tunnel conditions. In summary, GA3, KNO3 and prechilling were the most effective pre-treatments to improve the germination and seedling growth of cannabis genotypes and breaking seed dormancy. Therefore, it was concluded that cannabis genotypes had physiological dormancy.

Effect of alternative pre-treatments and fermentation on quality characteristics of oyster mushrooms

AbstractBesides their unique taste and texture, mushrooms are a promising source of important nutrients, including dietary fiber, amino acids, minerals, and vitamins. Fresh mushrooms, however, can only endure for a brief time, typically up to three days at ambient conditions. Different methods have been used to preserve mushrooms for a prolonged period, such as drying, cooking, frying, irradiation and fermentation. The objective of the current study is to investigate the effect of different pre-treatments and fermentation on physicochemical, textural, and microbial properties of oyster mushrooms. The fresh oyster mushroom was considered as control and 6 alternative pre-treatment methods were used as; blanching in water, steaming, oven cooking, microwave, High Hydrostatic Pressure and UV Light treatment. Moisture, pH, yield, color, texture, and microbiological analyses were performed on each pre-treatment group before and after fermentation. Our results showed that the quality attributes of oyster mushrooms were significantly affected by the usage of different pre-treatments.

Flame retardant effect of lignin/carbon nanohorns/potassium carbonate composite flame retardant on fir pretreated under different methods

Fir wood is widely used in construction, however its thermal degradability and flammability pose significant challenges to its safe use. In this work, we used a new carbonaceous nanomaterial called single-walled carbon nanohorns (SWCNHs), in combination with lignin and potassium carbonate to prepare a composite flame retardant and investigated the effect of different pretreatments on the flame retardant effect of fir wood. After delignification pretreatment and vacuum impregnation of fir wood with the flame retardant, the pk1-HRR and the pk2-HRR decreased by 37.59 % and 25.07 %, THP decreased by 55.71 %, TSP decreased by 59.81 %, COP significantly decreased by 74.02 %, char residual weight increased by 14.11 % compared with new wood (NW), and LOI reached 28.8 %. And the composite flame retardant forms a char layer during burning, which acts as a protective layer. This provides new insights into the application of SWCNHs in wood flame retardancy.

Sea Buckthorn Pretreatment, Drying, and Processing of High-Quality Products: Current Status and Trends.

Sea buckthorn is a kind of berry rich in nutritional and industrial value. Due to its thin skin, juicy pulp, and short shelf life, it is usually preserved via freezing methods or directly processed into sea buckthorn puree after harvest. It can also be dried and processed into products such as dried sea buckthorn fruit, freeze-dried sea buckthorn powder, and sea buckthorn oil. This review, therefore, provides an overview of the existing state of drying and high-quality processing of sea buckthorn. The effects of different pretreatment and drying techniques on the drying characteristics and quality of sea buckthorn and the existing problems of superior-quality processing of sea buckthorn products are summarised. The development trend of sea buckthorn drying methods and the ways to achieve high-quality processing of sea buckthorn products are indicated. These ways are mainly related to the following: (1) The application of combined pretreatment and drying techniques to find a balance between economy, ecology, and efficiency; (2) Introducing new online measurement and control technology into drying equipment; (3) Optimising the existing process to form a complete sea buckthorn industrial chain and develop the sea buckthorn deep-processing industry.

Effect of different pre-treatments on rehydration kinetics of solar and hot-air dried Fuji apple slices

The present study demonstrates the effect of direct solar drying (DSD) and hot air drying (HAD) on the quality attributes of Fuji apple slices. DSD samples took a longer time (150–180 min) to dry and simultaneously reached higher equilibrium moisture content at the end of rehydration than HAD samples. DSD samples have higher rehydration ability, dry matter holding capacity, and water absorption capacity than HAD samples. Among several empirical models, the Weibull model is the best fit with higher R2 (0.9977), lower root mean square (0.0029), and chi-square error (0.0031) for describing the rehydration kinetics. Rehydrated HAD samples showed better color characteristics than DSD in terms of overall color change, chroma, and hue angle values. Whereas the hardness and chewiness of rehydrated DSD samples were better than HAD samples because of higher dry matter holding capacity in DSD. Apart from color retention, the DSD samples showed better rehydration capacity and a good texture upon rehydration than HAD slices.

Flavor and sensory profile of Chinese traditional fish noodles produced by different silver carp (hypophthalmichthys molitrix) mince ingredients

This study employs sensory evaluation, headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS) techniques to investigate the effect of different pretreatment of fresh silver carp mince (running water rinsing 0, 1, or 2 times) and commercially frozen surimi on the odor characteristics of fish noodles. The free choice profiling (FCP) and check all that apply (CATA) sensory analysis methods were utilized to identify 10 characteristic descriptors, which include “grass, fish fragrance, unpleasant fishy, fatty, roast, ammonia, caramel, warmed-over, earthy, and mushroomy”. HS-GC-IMS and HS-SPME-GC-MS detected 80 and 37 volatile compounds (VCs) in fish noodles. The 1-Penten-3-ol, (E)-2-pentenal-D, hexanal-D, pentanal-D, (E,E)-2, 4-heptadienal-D contents were significantly correlated with “fish fragrance” and “unpleasant fishy”, and octanal, nonanal, heptanal, 2-methylpyrazine contents were significantly correlated with “warmed-over” flavor. The results of this study can be helpful for fish noodle quality improvement and industrial production.

Pretreatment of Aloe Vera and Its Effect on the Properties of Flour and Vermicelli Produced

Aloe vera powder has a less bright color due to the browning reaction. Pretreatment was carried out to improve the quality of aloe vera flour. Aloe vera flour can be used to manufacture food products, one of which is vermicelli. This study aimed to determine the effect of different pretreatments, namely blanching, sodium metabisulfite immersion, sodium bisulfite immersion, and steam blanching, on the characteristics of aloe vera flour and its application to vermicelli. The research steps included aloe vera pretreatment and aloe vera flour production, vermicelli production with aloe vera flour substitution, and analysis. The results showed that the pretreatment produced aloe vera and vermicelli flour with a brighter color. Pretreatment also affects water content, water-holding capacity, oil-holding capacity, and cooking properties. But the pretreatment did not affect the sensory properties of vermicelli.

A comparison of micro-flocculation and ozonation as pretreatments for ultrafiltration: organic removal and membrane fouling.

Micro-flocculation and ozone were applied as pretreatments of ultrafiltration to treat sodium alginate (SA) and humic acid (HA) simulated water, respectively, to investigate the effects of different pretreatments of ultrafiltration (UF) on filtration flux and removal of organic matters. Regarding the SA simulated water, micro-flocculation helped to improve the dissolved organic carbon (DOC) removal efficiency highly, maximum DOC removal efficiency reached to 79.77%, due to the rejection of gel layer introduced by the alginate-aluminum complexes, but the gel layer had a negative impact on membrane flux. Compared with micro-flocculation, ozone as pretreatments had better ability to enhance the membrane specific flux, the maximum final specific flux remained as 0.786, larger than that of MF-UF process (0.574). Ozonation oxidizing SA into small organic molecules significantly reduced membrane fouling and filtration resistance, but also produced some dissolved organic matters hindering DOC removal of effluent. As for HA simulated water, both the micro-flocculation and ozone could effectively improve the specific flux, the final specific flux of MF-UF and ozone-UF were about 0.930, but MF-UF exhibited better DOC removal than ozone-UF, which avoided the introduction of additional dissolved organic matters.

Effect of pretreatment on the interfacial bonding strength between modified polyolefin and aluminum foil treated with trivalent chromium chemical conversion: Experimental, quantum chemical calculations and molecular dynamics simulation

Good adhesive strength and joint durability are necessary for aluminum (Al)/polymer laminated film for lithium-ion battery packages. A pretreatment method involving alkaline degreasing followed by acid pickling was employed to treat the Al foil surface to facilitate the deposition of trivalent chromium [Cr(III)] conversion coating on the surface. The adhesive strength between propylene-based elastomer grafted glycidyl methacrylate (GMA-g-PBE) and Cr(III)-converted Al foil pretreated with 0.5 M HF pickling was 51% higher than Cr(III)-converted Al foil without pretreatment. Moreover, the effect of different pretreatments on the interfacial bond strength of GMA-g-PBE/Cr(III)-converted Al foil was studied from macroscopic to microscopic perspectives. The results indicate that the pretreatment of 0.5 M HF pickling results in complete coverage of the Cr(III) compounds and the formation of a thicker Cr(III) conversion coating on the Al foil compared to other pretreatments. A higher content of Cr(III) compounds results in an increased surface free energy of Cr(III)-converted Al foil, improving the wettability of adhesive melt on the substrate and enhancing the adhesion strength. Moreover, quantum chemical calculations and molecular dynamics simulations were used to investigate the interface bonding mechanism, and the results indicate that GMA in the adhesive exhibits a higher binding energy with Cr(III) oxides and hydroxides compared to Al oxides and hydroxides.

Effect of Pre-treatments on Shelf Life and Quality of Dried Pineapples (Ananas comosus)

This study aims to determine the effect of different pre-treatment and freezing on the quality of dehydrated pineapple using a food dehydrator with a convective drying method. The variations of pre-treatment conducted include control variation (K), immersion in sucrose solution (G), sucrose-citric acid mixture (GS), citric acid (S), thermal blanching (B), and kapur sirih or betel lime solution (KS), with and without freezing process before drying. The S variation resulted in the best shelf life of dried pineapple, lasting 106 days under room conditions using 0.75% citric acid solution. The shelf life of dried pineapple with pre-treatments K, G, GS, B, and K, respectively, were 61, 49, 33, 72, and 20 days. Drying and all types of pre-treatments resulted in a darker colour compared to fresh pineapple. Drying and all types of pre-treatments also yielded higher firmness values compared to fresh pineapple. Freezing prior to drying resulted in a darker colour for dried pineapple compared to unfrozen dried pineapple. Freezing prior to drying also yielded a softer texture compared to unfrozen dried pineapples. According to a group of 32 untrained panellists in the age group of 20-24 years old, the G variation was the most preferred variation of dried pineapple.