Osmotic Dehydration Research Articles

Osmotic dehydration of radish for improving nutritional value

Osmotic dehydration of radish for improving nutritional value

IoT implemented Osmotic Dehydrator

Osmotic dehydration is a dehydration technique that allows the preservation of the organoleptic characteristics of the food and its nutritional properties compared to other preservation methods, such as hot air drying or solar drying. Studies on this dehydration process are usually carried out on a laboratory scale and with the constant presence of the evaluator, interrupting the process for sampling. That is why the main objective of this research was to build an automated osmotic dehydration equipment implementing the Internet of Things (IoT). The measurable factors involved in the process were determined, and the necessary sensors and actuators were chosen along with the best IoT alternative for the process. A prototype was built, which allows for controlling the agitation of the osmotic solution, temperature control, and remote monitoring of concentration and temperature variables. The equipment was tested by evaluating its performance in the dehydration of melon and apple, where the ANOVA tests demonstrated the significance (p < 0.05) of the factors chosen as part of the equipment design and their interaction with the process. In the apple samples, a weight loss of up to 44.007% and a water loss of 53.234% were obtained. For melon, the process showed greater efficiency in dehydration, with values of 75.259% for weight loss and 75.979% for water loss.

Key factors for the survival of Lactiplantibacillus plantarum IDCC 3501 in manufacturing and storage.

Functional microbiome development has steadily increased; with this, the viability of microbial strains must be maintained not only after the manufacturing process but also at the time of consumption. Survival is threatened by various unavoidable factors during freeze-drying and shelf storage. Here, the aim was to optimize the manufacturing process of the functional strain Lactiplantibacillus plantarum IDCC 3501 after freeze-drying and storage. Explosive growth was achieved using a medium composition with two nitrogen sources and a mineral, and growth was drastically improved by neutralizing the medium pH during the culture of L. plantarum IDCC 3501. Culture optimization involved a smaller cell size, leading to less intracellular free water. Moreover, when maltodextrin (MD) powder was directly added to the harvested cells, some intracellular free water was extracted from the bacterial cells, resulting in a dramatic increase in the viability of L. plantarum IDCC 3501 after freeze-drying and subsequent storage. Furthermore, MD enhanced survival in a dose-dependent manner. Bacterial survival was correlated with lysozyme tolerance; therefore, the positive result might have been caused by the osmotic dehydration of intracellular free water, which would potentially damage the bacterial cells via ice crystallization and/or a phase transition during freeze-drying. These critical factors of L. plantarum IDCC 3501 processing provide perspectives on survival issues for manufacturing microbiome strains. KEY POINTS: • Culture conditions for probiotic bacteria were optimized for high growth yield. • Osmotic dehydration improved bacterial survival after manufacturing and shelf storage. • Reduction in intracellular free water content is crucial for intact survival.

The Quality Assessment of Sour Cherries Dried Using an Innovative Simultaneous Osmotic–Microwave–Vacuum Approach Based on Image Textures, Color Parameters, and Sensory Attributes

Sour cherries are a perishable raw material, and their preservation is needed to extend their availability to consumers. Improving drying techniques is desirable to ensure the highest quality of products. This study aimed to determine image textures from color channels R, G, B, L, a, b, X, Y, and Z; color parameters L*, a*, and b*; the color difference (ΔE) of raw materials and dried fruit; and the sensory attributes of dried sour cherry products prepared using an innovative approach. Three sour cherry cultivars, ‘Nefris’, ‘Debreceni Botermo’, and ‘Łutówka’, were used in the experiment. Sour cherries were subjected to freezing and pit removal before drying. The simultaneous osmotic–microwave–vacuum drying was carried out in one process lasting an hour and combining osmotic dehydration using a 40 °Bx sucrose solution and microwave–vacuum drying at microwave powers of 100 W for 900 s, 300 W for 900 s, 250 W for 900 s, and 0 W for stabilization for 900 s and a pressure of 30 ± 2 hPa. After drying, the quality assessment of products was performed using non-destructive image analysis and color measurements, as well as sensory analysis, including non-destructively and destructively assessed attributes. The highest changes in textures occurred for the GHMean (histogram’s mean for color channel G) (from 30.69 to 22.64) and LHMean (histogram’s mean for color channel L) (from 66.93 to 59.07) of images of the cultivar ‘Łutówka’, and the smallest changes were found for the cultivar ‘Nefris’. Drying had a statistically significant effect on the color parameters of the ‘Debreceni Botermo’ and ‘Łutówka’ sour cherries. The value of ΔE was the highest (10.44) for ‘Debreceni Botermo’ and the smallest (1.98) for ‘Nefris’. All cultivars of dried sour cherries had very high values of overall quality, reaching 8.9 for ‘Nefris’ and ‘Debreceni Botermo’ and 8.8 for ‘Łutówka’. The ‘Nefris’ sour cherry was characterized by the highest value of flavor of 9.0. All dried samples were attractive in terms of their external appearance. The sensory parameters related to taste, texture, and crunchiness were also satisfactory. Innovative simultaneous osmotic–microwave–vacuum drying allowed for the obtainment of dried sour cherries with a high quality, including acceptable sensory attributes.

Optimizing Drying Conditions of Lemon Rings Combined with Microwave Drying and Osmotic Dehydration

Kurutma süresini kısaltmak, ürün kalite özelliklerini iyileştirmek için ozmotik dehidrasyon ön işlemi ile birlikte birçok kurutma tekniği beraber kullanılmış olup, ozmotik kurutma ile mikrodalga kurutmanın birlikte kullanılması da bu yöntemlerden biridir. Ozmotik dehidrasyon ve mikrodalga kurutma işleminin birlikte kullanılarak kurutma yapılması mikrodalga kurutmanın olumsuz etkilerinin azaltılmasına yardımcı olur. Bu çalışmada, limon halkaların ozmotik dehidrasyon ön kurutma işlemi uygulanmasından sonra mikrodalga fırında kurutma koşullarının optimum seviyeleri Yanıt Yüzey Yöntemi ile belirlenmiştir. Yanıt Yüzey Yöntemin de kurutma parametreleri olarak ozmotik dehidrasyon süresi, çözelti derişimi, mikrodalga kurutma süresi ve mikrodalga gücü seçilmiştir. Optimize edilecek yanıtlar ise nem kaybı, çapsal büzülme oranı ve b renk değeri değişimi olarak belirlenmiştir. Dört faktör üç seviye için Box-Behnken tasarımına göre belirlenen 29 deney yapılmış ve yanıtlar alınmıştır. Dört faktörlü üç seviyeli Box-Benchken deneysel tasarım yöntemi, A ozmotik dehidrasyon süresi (60-180 dk), B çözelti derişimi (% 10-20 (w:v)), C mikrodalga kurutucuda kurutma süresi (2-6 dk) ve D mikrodalga güç seviyesi (100-300 W) aralığında uygulanmıştır. Elde edilen veriler ANOVA ile analiz edilmiş ve en yüksek R2 değerlerini veren nem kaybı için 0,9853, çapsal büzülme oranı için 0,9861 ve b renk değeri değişimi için 0,9770 ile kuadratik modellerin uygun olduğu belirlenmiştir. Nem kaybı üzerine C, D, CD, A², C² ve D² değişkenleri, çapsal büzülme oranı üzerine A, C, D, D² değişkenleri ve b renk değeri değişimi üzerine ise A, C, D, A² değişkenlerinin etkisinin önemli olduğu görülmüştür. Kurutma parametrelerinin optimum değişken seviyelerinden olan ozmotik dehidrasyon süresi 120 dk, çözelti derişimi %15, mikrodalga kurutma süresi 4 dk ve mikrodalga güç seviyesi 200 W olarak bulunmuştur.

Optimization and modeling of vacuum impregnation of pineapple rings and comparison with osmotic dehydration.

The vacuum impregnation (VI) process parameters (vacuum pressure=20-60kPa; VI temperature=35-55°C; concentration of the sucrose solution=40-60°Brix; and vacuum process time=8-24min) for pineapple rings were optimized based on the moisture content (MC), water loss (WL), solids gain (SG), yellowness index (YI), and total soluble solids (TSS) content of pineapple rings using response surface methodology (RSM). A relationship was developed between the process and response variables using RSM and artificial neural network (ANN) techniques. The effectiveness of VI was evaluated by comparing it with the osmotic dehydration (OD) technique. The optimum condition was found to be 31.782kPa vacuum pressure, 50.441°C solution temperature, and 60°Brix sucrose concentration for 20.068min to attain maximum TSS, YI, SG, and WL, and minimum MC of pineapple rings. The R2 values of RSM models for all variables varied between 0.70 and 0.91, whereas mean square error values varied between 0.76 and 71.58 and for ANN models varied between 0.87-0.93 and 0.53-193.78, respectively. Scanning electron micrographs (SEM) revealed that parenchymal cell rupture was less in VI than in OD. The VI pineapple rings exhibited more pores and high SG, as compared to OD, due to the pressure impregnation. Spectroscopic analysis affirmed that the stretching vibrations of intermolecular and intramolecular interactions were significant in VI as against OD. The VI reduced the drying time by 35% compared to OD, with the highest overall acceptability score and lower microbial load during storage. PRACTICAL APPLICATION: Pineapple is a perishable fruit, which necessitates processing for extended shelf life. This study highlights the potential of the vacuum impregnation process as a promising alternative to conventional preservation methods such as osmotic dehydration for pineapples.

Optimization of osmotic dehydration in dragon fruit (Hylocereus Polyrhizus) slices using response surface methodology

Dragon fruit (Hylocereus polyrhizus) is emerging as a super crop because of its several health and therapeutic benefits and ease of cultivation even in degraded land. Using response surface approach, the process parameters for osmotic dehydration of dragon fruit slices included process temperature, syrup concentration and process time. Slices of size 20 x 20 x 5 mm were dipped into sugar syrup with a syrup to dragon fruit slice ratio of 4:1 (w/w). After osmotic dehydration, the initial moisture content of dragon fruit samples was reduced to 27.5-68.49% (wb), demonstrating water loss, solid gain, and mass reduction in the range of 18.01-65.9%, 6.3-17.9% and 9.31-50.6%, respectively. After statistical analysis of the data on water loss, solid gain, and weight reduction, it was shown that regression equations of second order provided the greatest match for all the experimental data. With a syrup to fruit ratio of 4:1 and a syrup concentration of 65.3° Brix at a syrup temperature of 56.5°C, a maximum water loss of 58.2% and a minimum solid gain of 7.7% were expected to occur in 240 minutes of osmotic dehydration.

Insight into the effect of osmosis agents on macro- and micro- texture, water distribution, and thermal stability of instant controlled pressure drop drying peach chips

To investigate the influence of sugar structure on the quality of peach chips produced using osmotic dehydration (OD) in combination with instant controlled pressure drop (DIC) drying, erythritol, glucose, maltose, and trehalose were selected as osmotic agents. The properties of the osmotic solutions, as well as the macro- and micro-texture, water distribution, and thermal stability of peach chips were investigated. Results showed that OD pretreatments inhibited the formation of large cavity structures. The highest hardness (101.34 N) and the lowest hydrophobicity (0°) were obtained in erythritol-OD samples. Trehalose-OD samples with the most homogeneous pore structure exhibited the highest crispness (1.05 mm) and the highest glass transition temperature (52.06 °C). Various absorption peaks of peach chips pretreated with different OD methods, characterized by Raman spectroscopy, suggested changes in composition and functional groups due to the diffusion of sugars into the cells of peach tissues, which also contributed to the higher Tg.

Influence of ultrasound pretreatment on drying characteristics of cocoyam (Xanthosoma sagittifolium) slices during convective hot air drying.

Convective hot air drying of cocoyam is risk-free and inexpensive to a significant level. However, hot air drying causes negative changes to the color, texture, flavor and nutritional content of cocoyam as a result of the prolonged drying. Recently, the innovative technology of ultrasound pretreatment has been applied in food processing to reduce the processing time, conserve energy and preserve the quality of the food product. Thus, there is need to investigate the effect of ultrasound pretreatment with distilled water (UDW) and ultrasound with osmotic dehydration (UOD) for different ultrasonic times (10-30 min) on the drying kinetics of cocoyam slices during convective hot air drying. Ultrasound pretreatment was applied at a frequency of 20 kHz and an output power of 600 W for UDW and UOD. The ultrasound-pretreated samples were further dried in a convective hot-air drying oven at 70 °C. UDW and UOD samples, respectively, had a 25% and 46% reduction in drying time compared to untreated samples. The UOD samples had the lowest activation energy (10.697 kJ), as well as the highest moisture diffusivity (3.782 × 10-10 m2 s-1 ) and mass transfer coefficient (2.006 × 10-8 m s-1 ), among the untreated and UDW samples. Wang and Singh, Page and Peleg models were found to be the most fitted models with respect to the drying characteristics of cocoyam for untreated, UDW and UOD samples, respectively. Ultrasound pretreatment technology is a potential non-thermal process that can be incorporated as a pretreatment method in the convective drying of cocoyam to reduce processing time, conserve energy and enhance cocoyam product shelf life. © 2023 Society of Chemical Industry.

ROSPECTS FOR THE USE OF WILD BERRY PROCESSING PRODUCTS AS FUNCTIONAL FOOD INGREDIENTS

The aim of this study is to substantiate the feasibility of processing wild berries (Viburnum opulus, Sorbus, Hippophae, Sambucus nigra) into functional food ingredients. The paper analyses the structure of powders from wild berries Viburnum opulus, Sorbus, Hippophae, Sambucus nigra, and investigates the content of micro- and macroelements in the powders; physicochemical parameters of wild berry powders (dry matter, mass fraction of moisture, dispersibility, mass fraction of reducing sugars, solubility, acidity) and dietary fibre content in Viburnum opulus, Sorbus, Hippophae, Sambucus nigra powders. The prototypes were made from high-quality fruit and berry raw materials not damaged by diseases and pests. To make the powders, the berries were dehydrated by osmotic dehydration, then dried in infrared dryers for 2 hours at 50°C to a mass fraction of moisture of 6–8 %. The dried berries were ground in a laboratory mill LZM-1. The structure of the berry powders was studied by electron microscopy. It was found that the powders have a crystalline porous structure and, accordingly, hydrophilic properties. This makes it possible to use them in food production as structure stabilisers, emulsifiers and moisture retainers. The content of some minerals in the samples was studied using a microscope-based SEM and EDS detector. It was found that the powders contain macronutrients (K, Ca, P, Cl, S, N), essential trace elements (Mg) and the conditionally vital trace element Si, which was found in powders from viburnum and sea buckthorn. The obtained powders from wild berries Hippophae rhamnoides L., Viburnum opulus, Sambucus nigra and Sorbus aucuparia contain a significant amount of vitamin C. According to all physicochemical parameters, the samples of plant powders from viburnum, elderberry, sea buckthorn, and mountain ash berries meet the requirements of DSTU 8498:2015. These results indicate the feasibility of processing Viburnum opulus, Sorbus, Hippophae, Sambucus nigra into functional food ingredients.

Simultaneous valorization of discarded tomato and whey through osmotic dehydration: Development of high value-added products, rheological characterizations, and mass transfer modeling

Simultaneous valorization of discarded tomato and whey through osmotic dehydration: Development of high value-added products, rheological characterizations, and mass transfer modeling

Exploring the potential of osmotic dehydration with honey to develop value-addedfood from watermelon (Citrullus lanatus) rind

Exploring the potential of osmotic dehydration with honey to develop value-addedfood from watermelon (Citrullus lanatus) rind

An effective cryobanking approach preserving the genetic, physiological and phytochemical stability of Polyscias filicifolia Bailey hairy roots

Cryopreservation procedures can affect the physiological and genetic stability of stored samples, as well as their biosynthetic potential, which is particularly important for medicinal plants; as such, it is necessary to refine a number of factors to ensure the effective long-term storage of plant cells. The article describes an effective method of cryopreservation of Polyscias filicifolia hairy roots. Briefly, hairy roots were subjected to osmotic dehydration (OD) with or without subsequent air dehydration (AD; for three to six hours) for cryobanking in liquid nitrogen. After regeneration, genetic stability was assessed using Inter Simple Sequence Repeats (ISSRs) and Start Codon Targeted (SCoT) markers, together with nuclear DNA content, survival rate and biomass growth. In addition, chlorogenic (CGA) and oleanolic acid (OA) yields were determined using HPLC-UV-Vis, and the extract profiled by HPLC-PDA-ESI-HRMS, and the antioxidant potential of the treated root extracts was assessed. OD alone was found to be insufficient for cryopreservation; it was necessary to precede it with AD. The highest survival (93%), and biomass growth (up to 3-fold), were noted for roots subjected to OD preceded by six-hour AD; however, AD had a detrimental effect on the genetic stability of roots when applied for five or six hours. Longer dehydration times correlated with greater CGA biosynthesis. Further, CGA content was enhanced to 2.6 mg g−1 dry weight (DW) at six months post regeneration and 2.2 mg g−1 at 12 months. OA yield was not affected by the cryopreservation conditions. HPLC-PDA-ESI-HRMS analysis confirmed that the main component was CGA, accompanied by ferulic acid derivatives, 3,5-O-dicaffeoylquinic acid (isochlorogenic acid A) and 5-p-coumaroylquinic acid. Interestingly, the profile of biosynthesized compounds in the roots did not change during cultivation for up to 12 months. The highest antioxidant activity, determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assay, was noted for the extract from the OD variant, which also demonstrated the highest total phenolic content. Our findings indicate that OD followed by four-hour AD provides the best protection for hairy root meristems with regard to genetic stability, reliable growth and secondary metabolite biosynthesis capabilities.

The Influence of Rowan Powder on Physico-chemical and Microbiological Indicators of Wheat Flour Bread

Topicality. Bread is a strategically important food product for daily use. It contains a great amount of carbohydrates, vegetable proteins, fats, essential acids, and minerals. The nutritional value and saturation with complex carbohydrates make the bread valuable. However, the disadvantage of this product is quite a short shelf life (no more than 72 hours). Along with many benefits, premium wheat flour bread contains less fiber and vitamins than whole grain bread. The aim of the aricle and research methods. The aim of this study is to determine the effect of rowan powder on the quality indicators of wheat flour bread. As a natural supplement, a powder obtained from common rowan Sorbus aucuparia in laboratory conditions was used. The powder manufacturing method included preliminary freezing of rowan fruits (t=–18±2 °С), defrosting, osmotic dehydration in 70 % sugar grout (t=50±2 °С, τ=1,5 hours), drying (t=60±2 °C, τ=2,5 hours), and grinding. To assess the quality indicators of bread prototypes, generally accepted methods and regulatory documents were used: DSTU 9188:2022, DSTU 7045:2009. Organoleptic indicators were determined using the sense organs, and acidity with the help of titration method. To identify the shelf life, the samples were stored at room temperature without access to light and in plastic bags. Results. It is established that the addition of 10% rowan powder has a positive effect on the indicators of dough quality. Its acidity increases by 7.9 degrees, and the lifting force rises by 140 s. In addition, the moisture content of finished products increases as well that has a positive effect on the storage capacity of bread. It is established that the addition of rowan powders makes it possible to increase the shelf life of wheat flour bread up to 8 days. Conclusions and discussion. The addition of rowan powder helps to reduce the duration of dough fermentation up to 40 minutes and extend the shelf life of bread to 6 days.

The Effect of Ultrasound and Pulsed Electric Field on the Osmotic Dehydration Process of Strawberries

Currently, the demands of consumers are growing, and they expect safe and natural products of higher quality compared to products processed using thermal methods. Thermal treatment influences the sensory as well as quality and nutritional value of processed plant material. This results in the development of innovative, non-thermal methods of food preservation and processing. Hence, the study was conducted to examine how ultrasound (US) and pulsed electric field (PEF) affect the osmotic dehydration process of strawberries. An US treatment with a power of 400 W and a frequency of 24 kHz for 30 and 90 s and a PEF treatment were used, adopting the appropriate energy consumption of 1 and 2.5 kJ/kg. Then, strawberries after both processes were osmotically dehydrated in 0.5; 1, and 2 h at 30 °C. Dehydration was carried out in a 50% sucrose solution. Research findings have indicated that the pretreatment positively enhanced the efficiency of osmotic dehydration. An improvement in the dry weight gain rate was noted. Strawberries dehydrated with the use of pretreatment had similar or lower color values and the content of bioactive components compared to strawberries subjected to dehydration only. The material treated with the PEF turned out to be the softest. Significant differences in sugar content were noted in fruits after pretreatment. Sucrose levels increased, glucose levels decreased, and fructose remained at a comparable level.

Effect of osmodehydration on the quality attributes of plum (Prunus domestica)

Plum (Prunus domestica) is a seasonal nutraceutical fruit rich in many functional food nutrients such as vitamin C, antioxidants, total phenolic content, and minerals. Recently, researchers have focused on improvised technologies for the retention of bioactive compounds during the processing of perishable fruits; plum is one of these fruits. This study looked at how the percentage of moisture content and percentage of acidity were affected by conventional drying and osmotic dehydration. Total phenolic content (mg GA/100 g of plum), total anthocyanin content (mg/100 g), and vitamin C (mg/100 g) Conventional drying of fruit was carried out at 80.0 ℃ for 5 h. At various temperatures (45.0 ℃, 50.0 ℃, and 55.0 ℃) and hypertonic solution concentrations (65.0 B, 70.0 B, and 75.0 B), the whole fruit was osmotically dehydrated. It was observed that the osmotically treated fruit retains more nutrients than conventionally dried fruit. The total phenolic content of fruit significantly increased with the increase in process temperature. However, vitamin C and total anthocyanin content of the fruit decreased significantly with process temperature, and hypertonic solution concentration was observed. Hence, it was concluded that osmodehydration could be employed for nutrient retention in plum fruit over conventional drying. This process needs to be further refined, improvised, and optimised for plum processing.

Development of a powdered food additive based on sea buckthorn fruit

In the process of food production, it is important not only to obtain a high quality product, but also to minimize industrial waste and reduce energy costs for the process. Recently, customers have been paying particular attention to the biological value of products, and the popularity of organic and natural products is growing. The search for new types of unconventional raw materials and the choice of a rational method of their processing is an important task for scientists and manufacturers. The aim of the study is to develop a technology for the production of a powdered food additive by using wild-growing raw materials of regional importance by osmotic dehydration. The use of osmotic dehydration preserves their biological value and organoleptic properties. The technology of osmotic dehydration processing of berries developed in this work allows the use of gentle drying modes, which contributes to the maximum preservation of their biological value. The presence of biologically active substances in sea buckthorn improves the chemical composition of food products. Standard organoleptic and microbiological methods of research were used. The article presents a technological scheme for the production of a powdered food additive based on sea buckthorn fruit. The physicochemical and organoleptic parameters of the finished product, the content of vitamins C and E were investigated. Given that wild berries were used for the study, the powders were tested for the presence of microorganisms (bacteria of the E. coli group (coliforms), the number of mesophilic aerobic and optional anaerobic microorganisms, yeast and molds) and toxic elements. All indicators are within the permissible limits. Thus, sea buckthorn fruit is a safe raw material. The microbiological parameters during long-term storage for 12 months were determined.

Catalytic infrared blanching and ultrasound sequential synergistic pretreatment on osmotic dehydration of blueberry

This study investigated the effects of catalytic infrared blanching, ultrasound, and their combined pretreatments on the dehydration of blueberries. The results showed that catalytic infrared blanching for 6 min facilitated the retention of total phenols and total anthocyanins after the osmotic dehydration of blueberries. The polyphenol oxidase relative enzyme activity and hardness were reduced, while the brightness and relative conductivity were increased. Moreover, the solid gain and water loss were significantly increased with the combined pretreatment of catalytic infrared blanching and ultrasound (60, 40, and 40 + 60 kHz). Reducing the contact angle (from 120.8° to 63.5°) may strengthen the ultrasound cavitation. Furthermore, the drying rate, bioactive components, antioxidant capacity, and color of dried blueberries were evaluated. Compared to the control, the retention of total anthocyanin and the brightness increased. Catalytic infrared blanching combined with ultrasound pretreatment was a processing method to improve the osmotic dehydration efficiency of blueberries. This article deals with osmotic dehydration, a method that partially removes water from blueberries. Ultrasound is considered an effective pretreatment for enhancing mass transfer during osmotic dehydration. The waxy coating on the fresh blueberry epidermis, however, greatly reduces the cavitation effect of ultrasound due to an air film between the epidermis and the solution. Catalytic infrared blanching reduces the hydrophobicity of the epidermis. Catalytic infrared bleaching not only inactivates the enzyme activity in blueberries but also reduces the hydrophobicity of the blueberry skin. In this study, catalytic infrared bleaching was first combined with ultrasound for pre-penetration pretreatment of blueberries, which effectively improved water loss and solids increment during the penetration process as well as enhanced retention of blueberry anthocyanins. Highlights CIB reduced the PPO relative enzyme activity and the contact angle. CIB combined with US significantly increased WL and SG. CIB or US pretreatment improved the retention of TAC, TPC, and TFC.

Optimization of osmotic dehydration of orange pieces (valencia late) in sugar solution using response surface methodology

Response surface methodology was used to determine the optimum processing conditions that yield maximum water loss and weight reduction and minimum solid gain during osmotic dehydration orange pieces (valencia late) in sugar solution using response surface. The experiments were conducted according to a Central Composite Design ‘CCD’. The independent process variables for osmotic dehydration process were temperature (40, 50, 60 °C), processing time (60, 120 et 240 min) and sugar concentrations (45, 55, 65 % w/w). The optimal conditions for maximum water loss, weight reduction and solid gain (candying) correspond to temperature of 50 °C, processing time of 240 min, sugar concentration of 65 % in order to obtain water loss 60.83 % (g/100 g fresh sample), solid gain of 46,48 % (g/100 g fresh sample) and weight reduction of 57.42 (g/100 g fresh sample). However the optimal conditions for maximum water loss and weight reduction and minimum solid gain (respectively 53.28 %, 57.88 % and 27.18 %) correspond to temperature of 40 oC, processing time of 240 min, sugar concentration of 65 %.

Optimization of osmotic dehydration of tomatoes slices in salt and sucrose solutions using response surface methodology

Response Surface Methodology (RSM) was used to investigate the effect of temperature solution, immersion time, salt concentration and sucrose concentration on the water loss and solid gain during osmotic dehydration of tomatoes slices. The optimum conditions for maximum WL% and SG % are: T=55°C, t =240 min and C=74% for the sucrose and T=55°C, t= 240 min and C= 5% for the salt. The value of water content of the monomolecular layer (Xm),is 17.07 % at 25°C.