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Application of osmo-air dehydration for processing of tropical fruits in rural areas
Abstract
Osmotic dehydration has received greater attention in recent years as an intermediate step in drying of several fruits and vegetables. Being a simple process, it has potential advantages for the processing industry for dehydration of tropical fruits with longer shelf life. It also results in quality improvement in terms of colour, flavor, texture, product stability, nutrient retention and prevention of microbial spoilage during storage. The inclusion of osmotic process in conventional dehydration has two major objectives-quality improvement and energy savings. Different factors like pretreatments, nature and concentration of osmotic solution, raw material characteristics, stage of ripeness/ maturity, size of slices, duration of osmosis, ratio of slice to syrup, temperature, agitation, and additives are known to influence the product quality. At the terminal stage the final drying can be achieved, using, cabinet driers, solar driers or bio-fuel driers. India has a rich variety of tropical fruits which are in great demand world wide due to their excellent flavor and nutritional qualities. Based on these advantages it is predicted that osmotic process is very useful and has greater scope for utilization of several fruits such as banana, jackfruit, sapota and guava in addition to mango and pineapple. This process can be adopted as a rural based simple technology by small entrepreneurs, home-scale industries, and also by shelf help group in close association of NGOs. There is ample scope of cost reduction through the use of solar energy for syrup concentration and dehydration process. Brief information about the osmotic dehydration process, effect of variables based on recent findings, and status of international trade in dehydrated fruits has been presented.
... Sucrose is the osmotic agent most suitable for fruits, although other substances, including sucrose, Glucose, fructose, lactose, l-lysine, glycerol, polyols, maltodextrin, starch syrup, or combinations of these solutes, can be used 26,27 . Osmotic dehydration is the phenomenon of water removal from lower concentration to higher concentration solute through a permeable membrane, resulting in the equilibrium condition on both sides of the membrane 28 . It has been found to have wide applications in preserving food materials since it lowers the water activity of fruits and vegetables. ...
This study employed the Taguchi technique to investigate the influence of various liquid nitrogen quick-freezing parameters on litchi fruit cracking, nitrogen consumption, and freezing time. The experiments included testing different freezing temperatures (− 40, − 50, − 60, and − 70 °C), two types of nitrogen spraying nozzles (Hollow-cone and Full-cone), and two fan speeds (800 and 1200 rpm). Before freezing, the litchis were soaked in a solution and precooled as a pre-treatment to mitigate peel cracking and preserve quality. The results revealed that the crack ratio, freezing time, and nitrogen consumption decreased as temperature and fan speed increased. Among the nozzle types, Full-cone nozzles exhibited superior performance, achieving reductions of more than 15% in crack ratio, over 8% in freezing time, and more than 4% in nitrogen consumption compared to Hollow-cone nozzles. The predicted values derived from the Taguchi method showed strong alignment with the experimental data, validating the robustness of the optimization approach. This study contributes novel insights to the field of food freezing technology by introducing an innovative method for minimizing fruit cracking during freezing without the need for packaging. The findings also highlight the potential for reducing freezing time, operational costs, and nitrogen usage, offering practical implications for the food processing industry.
... As a result, 55 °B sugar solution and 60 °C drying temperature were employed. Osmotic dehydration is nothing but the phenomena where water is transferred from a solution with a lower solute concentration to one with a greater concentration across a semipermeable membrane, creating an equilibrium on both sides of the membrane (Tiwari, R.B., 2005). As an osmotic agent for Osmotic dehydration, a variety of solutes are employed, including fructose, maize syrup, glucose, sodium chloride, and sucrose. ...
... It is done by immersing food materials either in whole or units into a hypertonic solution which allows diffusion of solutes from the food material into the solution concurrently with solid impreg-nation into the food material (Ciurzynska et al., 2016). As Tiwari (2005) has mentioned, osmotic dehydration is the phenomenon of water removal from a lower concentration of solute to a higher concentration through a semipermeable membrane, resulting in the equilibrium condition on both sides of the membrane. In osmotic dehydration, the basic hypertonic solutions used are generally sugar syrup with fruits and sodium chloride or brine with vegetables (Bonatsou et al., 2016). ...
Five varieties of black chokeberries were analysed at fresh, intermediate (after the osmotic treatment) and dried stages,
(after dehydration) comparing their soluble solids, total sugar, titratable acidity, vitamin C, phenols and anthocyanins content. The study aims to find various correlations between the osmotic treatment and the sensory & nutraceutical qualities of fruits and time & energy savings, as well. The hypertonic solutions were represented by a natural concentrated fruits juice in the ratio 1:2, 1:3 and 1:7 and by an inverted sugar syrup in the same ratios. Uncrushed berries were used, at the temperature of 50° C into syrup immersion and convective dehydration, subsequently.
... Mặc dù, hàm lượng Vitamin C giảm trong quá trình chần nhưng enzyme hoá nâu bị vô hoạt cũng như hàm lượng chất khô ít tổn thất khi chần trong thời gian 2 phút, nên được đề nghị cho các bước xử lý tiếp theo. Khi ngâm thực phẩm trong dung dịch thẩm thấu, nước di chuyển từ nơi có nồng độ chất tan thấp đến nơi có nồng độ cao hơn qua màng bán thấm, dẫn đến trạng thái cân bằng giữa bên trong và ngoài màng (Tiwari, 2005). Độ ẩm của nguyên liệu mãng cầu giảm ý nghĩa theo thời gian ngâm (p<0,05). ...
Mãng cầu xiêm (Annona muricata L.) có nhiều giá trị dinh dưỡng tốt cho sức khỏe cũng như hương vị thơm đặc trưng nên được nhiều người ưa chuộng. Việc tận dụng nguồn nguyên liệu mãng cầu xiêm dồi dào trong chế biến sản phẩm mãng cầu sấy dẻo góp phần nâng cao giá trị và đa dạng hóa sản phẩm từ mãng cầu xiêm. Trong nghiên cứu này, quá trình chần, thẩm thấu và sấy sẽ được khảo sát. Kết quả cho thấy mãng cầu chần (hấp) trong 2 phút thì vô hoạt enzyme peroxidase và vitamin C duy trì cao (112,79 mg%). Thêm vào đó, quá trình ngâm mãng cầu trong dung dịch 50% đường, 2 giờ thì đạt hiệu quả về tách nước và yêu cầu về chất lượng. Tiếp theo, mãng cầu được phối trộn với tỷ lệ muối (1%) và bột ớt (0,1%) và được sấy ở 60oC trong 5,5 giờ cho sản phẩm đạt giá trị cảm quan và dinh dưỡng phù hợp. Cụ thể, sản phẩm có độ hoạt động nước (aw) 0,67±0,04, độ ẩm 19,26±0,97%, vitamin C 20,86±1,02 mg% và mức độ ưa thích 6,80±1,16 điểm (trên 9 điểm).
... Osmotic dehydration is the preferred preservation technology for most fruits and vegetables. This drying process is widely applied in the Assessing the Physicochemical Characteristics: A Comparative Analysis of Various Drying Methods in Osmotic Treated Fruit... preservation of food materials since it lowers the water activity of fruits and vegetables by removing water from a lower concentration of solute to a higher concentration through a semipermeable membrane and subsequent dehydration (moisture reduction process) (Tiwari, 2005). However, osmotically dehydrated end product qualities are affected by various factors such as preliminary treatments, the concentration of the osmotic solution, the quality of the raw material and its maturity, the shape and size of the slices, the duration of the osmosis process, agitation, temperature, additives, drying technique types and dehydration parameters (temperature, relative humidity, heat sources and duration of drying). ...
Background: Due to their high perishability, we cannot store fruits in their fresh form for long. The different drying techniques have affected the physical and nutritional qualities of the dried fruit pieces. Adoption of osmotic dehydration will help to protect and improve the quality characteristics of the final products. Methods: Selected fruit slices, viz., apple, pineapple, guava, mango and banana, were subjected to sugar osmosis (60°Bx for up to 48 hours), followed by drying in different drying methods, viz., open sun (ODT), solar tunnel (SDT) and hot air drying (CDT) and the physical and chemical characteristics of the end products were analysed. Result: The osmosis process improved the total soluble solids content, while CDT and SDT improved both the rehydration of the dried fruit slices and the percentage of weight loss. The desirable physical attributes of the dried products significantly varied among the different drying methods and within the fruit slices. The CDT-dried samples had better nutritional properties in terms of total phenol content and antioxidant activity than did the other drying methods and fresh samples, except for vitamin C content, which was greater in fresh fruit slices. The results recommended using CDT techniques in osmosis-treated fruit slices, which could improve fruit's physical and nutritional properties and be useful as good functional foods for a long time.
... This phenomenon is involving with the diffusion of water from fruit or vegetable to the solution (generally sugar syrup or brine) and the migration of sugar or salt towards the fruits and vegetables. The water remove from lower concentration of solute to higher concentration through semi permeable membrane until the concentration of the solute reaches the equilibrium condition in both sides of membrane (Tiwari 2005). ...
This research aims to use the waste syrup from sweet pickled Ma-Muang-Bao production for gummy development. The gummy basic recipe was chosen from three commercial gummy recipes by using rank sum differences method. The gummy recipe that gained the highest rank sum difference was chosen for further experiment. In order to develop the gummy recipe and investigate the factors that affected the sensory attributes of the gummy, the experiment was designed by using 2 x 2 factorial, two levels of the waste pickled mango syrup's total soluble solid (23 o brix and 33 o brix) and citric acid (0.5% and 1%) were examined by using the sensory evaluation. For the sensory evaluation, consumer preference test and just about right test were conducted by using a total of 30 panelists. The sample that had highest preference score was chosen and further improved for its better attributes according to the just about right score. Consumer acceptance and buying decision was examined by a total of 50 panelists. The results revealed that the rank sum differences of the overall liking of gummy recipe B which contained 8% of gelatin, 31% of sugar, 30% of glucose syrup, 1% of citric acid and 30% of waste pickled mango syrup had the highest score on texture and overall liking but not significantly lower than gummy recipe A on taste and flavors. The study on the factors that affected the gummy sensory found that the total soluble solid of the waste syrup (brix) was the main factor that affected the pickled mango flavor, sweetness and saltiness of the gummy while yellow color, gumminess and sourness of the gummy were depended on citric acid content. Gummy recipe B made from 23 o brix of waste pickled mango syrup and 0.5% of additional citric acid (T1), had the significantly highest liking score on overall preference, yellow color, pickled mango flavor, sweetness, saltiness and sourness. The consumer acceptance test revealed that the majority of the panelists very liked the gummy color (8.02 ± 0.68), the gumminess (8.34 ± 0.48), the sweetness (8.24 ± 0.49) and overall preference (8.56 ± 0.40) while they were moderately like the gummy flavor (7.86 ± 0.48), sourness (7.87 ± 0.37) and saltiness (7.76 ± 0.58). The majority of panelists (98%) accepted this product and 95% of them decided to purchase the developed gummy at 35 THB per 70 g (7 pieces). The researchers suggest that further market research should be performed to develop effective product positioning strategies.
... The aim of salting is to preserve the sea cucumber before processing and to remove extra water from the body wall through osmotic dehydration [12,23]. Through osmotic dehydration, water is removed from the lower-concentration region of a cell to the highconcentration region through a semipermeable membrane [63]. Osmotic dehydration is required to retain the colour, aroma, and nutritional components of sea cucumbers [64]. ...
Sea cucumbers are well demarcated for their valuable role in the food, pharmaceutical, nutraceutical, and cosmeceutical sectors. The demand for well-processed dried sea cucumber retaining quality is prioritized by local markets and industries. There are several techniques for the pre-processing of fresh sea cucumbers, including traditional and modern methods, such as salting, boiling, high-pressure processing, high-pressure steaming, and vacuum cooking, among others, in order to inactivate enzymes and microbial attacks. Further, pre-treated sea cucumbers require post-processing before human consumption, transportation, or industry uses such as hot air, freeze, cabinet, sun, or smoke drying. However, despite the ease, traditional processing is associated with several challenges hampering the quality of processed products. For instance, due to high temperatures in boiling and drying, there is a higher chance of disrupting valuable nutrients, resulting in low-quality products. Therefore, the integration of traditional and modern methods is a crucial approach to optimizing sea cucumber processing to obtain valuable products with high nutritional values and retain bioactive compounds. The value of dried sea cucumbers relies not only on species and nutritional value but also on the processing methods in terms of retaining sensory attributes, including colour, appearance, texture, taste, and odour. Therefore, this review, for the first time, provides insight into different pre- and post-treatments, their perspective, challenges, and how these methods can be optimized for industry use to obtain better-quality products and achieve economic gains from sea cucumber.
... Osmotic dehydration and convective drying are processing techniques for preserving fruits and vegetables. OD is the removal of water from low to high concentrations of solute through a semipermeable membrane (Tiwari, 2005). The water removal is accompanied by vitamins, flavors, pigments, and some minerals enabling shrinkage and loss of weight in the fruit or vegetable (Chandra & Kumari, 2015). ...
Carrot is a high-value crop loaded with nutritional benefits and an excellent source of vitamin A. Cordillera is known as the highest carrot producer in the country due to the region's temperate weather and vast farm areas. However, the region is not exempted from the prevalence of malnutrition and vitamin A deficiency despite being a top food producer in the country. In this study, a ready-to-eat snack item was developed to help increase the consumption of carrots. An experimental research design following the factorial method was used. Factor A is the amount of sugar (40%, 50%, and 60%) and Factor B is the method of osmotic dehydration (step-up method and one-step method). The products were subjected to sensory evaluation by a consumer-type panel using the 9-point Hedonic scale, a buying behavior through an attitudinal survey, product costing, basic nutritional evaluation, and recovery rate analysis. Results showed that the use of the step-up method obtained a higher level of acceptability in most of the quality attributes over the one-step method. The highest acceptability of the sugar concentration used is 60% with decreasing acceptance at 50% and 40%. The computed selling price is ₱50 per 100 grams packed in a re-sealable stand-up pouch. The consumers have positive responses to the marketability of the product. The recovery rate ranges from 27-29% regardless of treatments. There is a great change in the nutritional composition of the product compared to the fresh state of carrots.
Conventional nutrition research provides more information on how food promotes health and preventative medicine. Modern lifestyles encourage sustainable packaged food production. Current food technology uses fermentation, encapsulation, extraction, fat replacement, and enzyme processing to create nutritious food products, reduce, or eliminate unnecessary ingredients, add nutrients or fortified foods, alter ingredients, mask artificial flavors, and stabilize ingredients. 3D printing-compatible food ingredients promote these cost-effective, productive, user-friendly, and environmentally friendly food technology breakthroughs.
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