Fresh Onion Research Articles

Evaluation of Different Drying Techniques on Bombay Red Onion (Allium Cepa L) Basic Nutritional and Volatile Components

In this study performance of three drying methods on basic nutritional and important volatile components of red onion were evaluated. Onion (Allium cepa L.) is a strong-flavoring vegetable consumed in different ways, mainly due to its distinctive flavor or, simply pungency. It also has important natural compounds effective for medical functions such as inhibition of bone resorption, lower risk of cardiovascular disease, and cancer. This importance is directly related to a high content of organo-sulphur compounds. The shelf life of fresh onion bulbs are short enough about two weeks at ambient storage conditions in Fogera district, Amhara region, Ethiopia. This is mainly due to the presence of high moisture in fresh onion bulbs. Postharvest loss of onion bulbs also reaches up to 50% in the production season in Fogera district. Consequently, onion bulbs had extremely variable market price during production and off-season in the district, which directly influences both growers and consumers. The effects of different drying techniques on protein, carbohydrate, total sugar, fat, pyruvic acid, ascorbic acid, total phenol, total flavonoid, rehydration ratio, colour, and sensory properties of onion slice were evaluated and found insignificant at p > 0.05 for microwave and modified direct solar dryers, taking fresh onion bulbs as the control. However, oven drying methods had a significant effect on onion physicochemical quality attributes at p <0.05 as compared to fresh onion bulbs.

Antioxidant Activities and Taste Qualities of Fresh Onions Produced in Minamishimabara City, Nagasaki, Japan

Antioxidant Activities and Taste Qualities of Fresh Onions Produced in Minamishimabara City, Nagasaki, Japan

Garlic, Allium sativum L. and Onion, Allium cepa L. as a Potent Anti-mite Varroa destructor, Parasited on Honey Bee, Apis mellifera L. in Egypt.

The parasitic mite, Varroa destructor is one of the most important pests attacking apiaries all over the world. The aim of work is to evaluate the effects of fresh garlic, onion, mix of them, garlic oil and onion oil against Varroa mite in the honey bee colonies in Sohag Governorate. Data revealed that, all tested materials were effective when compared with control. The treatment with fresh garlic led to the highest percentage of fallen Varroa mite with 94.29% of the total Varroa presented in the bee colony, followed insignificantly by the mixture of garlic and onion (93.60%), garlic oil (91.55%) and onion oil (89.91%), however, the lowest percentage was recorded in fresh onion treatment with 85.33% of the total Varroa presented in the bee hive. Also, it is clear that the highest reduction percentage was recorded after the first application in all materials, the number of applications needed to satisfactory Varroa control differed depending on material type.

Changes in the antioxidant activity and metabolite profile of three onion varieties during the elaboration of ‘black onion’

This study aims to investigate whether the heat treatment applied during the production of black onion, a novel derived product made from fresh onion, produces changes in the content of flavonoids, organosulfur compounds, organic acids, water soluble sugars and amino acids in three onion varieties (‘Shallot’, ‘Chata’ and ‘Echalion’). The total flavonoid content decreased up to 12-fold in black onions compared with fresh onions while the quantities of isoalliin, the main organosulfur compound in black onions, drastically increased during the process. Moreover, the levels of fructose and glucose significantly increased during the elaboration process, contributing to the sweetness of black onions. The influence of heating on their antioxidant capacity showed a decreasing trend of the ORAC antioxidant activity of onion, while ABTS and DPPH did not show a clear tendency. These results present a comprehensive phytochemical characterization of black onions, highlighting the significant influence of the heating process on their phytochemical composition.

Effect of storage methods on some selected mineral and ascorbic acid content of red and white onion (Allium cepa)

The study investigated the influence of three different storage conditions in minimising the postharvest losses of onions. The fresh onion walla-walla variety (red and white) were obtained from Modibbo Isah Farms, Bichi, Kano State, Nigeria. The onions were stored for eight weeks under three different storage conditions which include: Ambient temperature (30 ± 2 ºC), refrigeration storage (5-7 ºC) and control cupboard temperature storage (45-50 ºC) during which the samples were analysed weekly. During the storage period of onion bulbs, the temperature ranged between (29-32 ºC) while the relative humidity was between (70 – 95 % RH).The mineral (calcium, sodium and potassium) content was determined by Atomic Absorption Spectrophotometry while Ascorbic acid was determined by the 2, 6- dichlorophenol indophenol (DCPIP) titration. The result showed that some components of the stored onions decreased with an increase in the storage period and these include: ascorbic acid (9.62-3.87mg/100g) and sodium content (12.13-11.77mg/kg). While some parameters also showed an increase with an increase in the storage period and these include: potassium content (30.00-72.12mg/kg) and calcium content (55-105mg/kg).

EFFECT OF DAYAK ONION TUBER (ELEUTHERINE AMERICANA MERR.) EXTRACT TO PREVENT INCREASED NECROSIS OF KIDNEY TUBULAR EPITHELIAL CELLS IN MICE (MUS MUSCULUS) TO ORAL LEAD ACETATE EXPOSURE

Objective: This study aims to determine the effect of Dayak onion tuber extract to prevent an increase in necrosis of kidney proximal tubular epithelialcells exposed to lead acetate.Methods: Fresh Dayak onion tuber was extracted with 96% ethanol and then given orally to mice with doses of 65 mg/kg, 130 mg/kg, and 260 mg/kgfor 21 days, accompanied by 14 days of lead acetate on the 8th–21st days. Histological preparations of the mice’s kidney were made by hematoxylinand eosin staining, and then, the necrosis of tubular cells was examined using a ×400 magnification light microscope that observed 5 views randomlymarked by the presence of pyknosis, karyorrhexis, and karyolysis.Results: This study showed the higher the dose of Dayak onion tuber extract and the lower the number of tubular epithelial cell necrosis (p<0.05).Conclusion: Extract of Dayak onion tuber could prevent an increase in necrosis of kidney proximal tubular cells of mice that exposed to lead acetate.

Comparison of Farmers’ Markets and District Markets in Terms of Marketing Efficiency: The Case of Seferihisar District in Izmir Province

Marketing is a process that begins before the production of goods and continues even after the sale has been made. That is why it is essential to market effectively and accurately. Besides, many problems occur sourced from production and marketing. The most important one of these problems is that the marketing system is controlled by intermediaries. Excessive intermediaries lead to product losses and costs. While farmers sell the goods at low prices, the excess marketing channels cause product prices to increase until it reaches consumers. In this context, as determining the marketing efficiency of farmers, it is aimed to offer solutions to these problems. The research area of this study is the farmers' market in Seferihisar district of Izmir province in Turkey. It was interviewed face-to-face with 75 agricultural farmers in the research area. According to the obtained study results, in the farmers' market, the product with the highest marketing efficiency index (MEI) was fresh onion (40.6). In district markets, the product with the highest MEI was found as leek with 5.80. The study also showed that as farm size increased, farmers had a higher MEI.

Evaluation of drying techniques on nutritional and volatile components of Bombay red onion (Allium cepa)

In this study performance of three drying methods on nutritional and important volatile components of red onion were evaluated. Onion (Allium cepa L.) is a strong-flavoring vegetable consumed in different ways, mainly due to its distinctive flavor or, simply pungency. The shelf-life of fresh onion bulbs are short enough about two weeks at ambient storage conditions in Fogera district, Amhara region, Ethiopia. This is mainly due to the presence of high moisture in fresh onion bulbs. Postharvest loss of onion bulbs also reaches up to 50% in the production season in Fogera district. Consequently, onion bulbs had extremely variable market price during production and off-season in the district, which directlyinfluences both growers and consumers. The effects of different drying techniques on protein, carbohydrate, total sugar, fat, pyruvic acid, ascorbic acid, total phenol, total flavonoid, rehydration ratio, colour, and sensory properties of onion slice were evaluated and found insignificant at P> 0.05 for microwave and modified direct solar dryers, taking fresh onion bulbs as the control. However, oven drying methods had a significant effect on onion physicochemical quality attributes at P <0.05 as compared to fresh onion bulbs.

Evaluación técnica de la agregación de valor a partir de variedades de cebolla (Allium cepa) cultivadas al norte de la Región Central Oriental de Costa Rica

El sector cebollero costarricense es dinámico y cuenta con una institucionalidad que respalda las acciones de investigación y extensión, como el Programa Nacional de Cebolla del Ministerio de Agricultura y Ganadería-MAG, las Agencias de Extensión Agropecuaria locales, y el Programa de Investigación y Transferencia de Tecnología Agropecuaria-PITTA Cebolla. Sin embargo, la comercialización en fresco de la cebolla enfrenta dificultades, por lo que este proyecto tuvo por objetivo “Evaluar el proceso de agregación de valor a variedades de cebolla (Allium cepa) cultivadas en zona Norte de la Región Central Oriental (al norte de Cartago). Se consideraron los materiales E515, Predator y Alvara, valorando dos variables principales para el análisis comparativo a partir de pruebas de valor agregado, considerando: tiempo de ejecución del proceso agroindustrial y rendimiento de producción. Las variedades Predator y E515 usualmente mostraron los rendimientos más altos y los menores tiempos de elaboración según el producto de valor agregado del que se tratara. Los resultados fueron transferidos a los beneficiarios en un taller teórico y tres sesiones prácticas en la Planta Piloto Agroindustrial del Instituto Tecnológico de Costa Rica (TEC). Se recomienda ahondar en investigaciones para validar los resultados hallados y se sugieren estudios de factibilidad específicos en el caso de desear incursionar en emprendimientos de este tipo.

Reining in Onion Prices by Introducing a Vertically Differentiated Substitute: Models, Analysis, and Insights

Onion is an indispensable ingredient of the Indian diet, and plays a vital role in Indian economy, society, and politics. The ongoing volatility in its prices leads to significant social unrest. In this paper, we are interested in helping decision-makers to rigorously evaluate policy proposals to remedy the situation. We identify conditions under which it is optimal to introduce a processed substitute and whether it should be managed by nonprofit or for-profit firms. Our models capture the inherent vertically differentiated competition over two periods, consumers' prejudice for the processed produce, and perishability of the fresh produce. We find ample evidence to work towards implementing the processed substitute policy. In addition, management by a nonprofit would be a far better solution, resulting in a much higher consumer surplus (by about 243\%) and lower prices (down to 48\%). While improved consumer perception is favorable in general, policymakers should be careful about some unintended consequences such as increased prices and lower availability. Moreover, contrary to the conventional wisdom, we find that a non-profit may purposefully choose a strategy where consumers do not purchase its offering when fresh onion deterioration is high and consumer prejudice is low. We also find that a for-profit firm would always choose to be the lower-quality substitute in the market when fresh onion deterioration is low.

Consumers’ Needs for Fresh Onions for Eating Raw that are Produced in Winter Season

Consumers’ Needs for Fresh Onions for Eating Raw that are Produced in Winter Season

Antibacterial Activity of Fresh Red and White Onion (Allium cepa) Extract against Some Drug Resistant Bacteria

Antibiotics resistance is currently one of the major challenges in the health care system. The antimicrobial properties of some herbs have been used in the treatment of infectious diseases as well as disinfection of surfaces. This in a way helps overcome microbial resistance arising from indiscriminate use of synthetic antimicrobial agents for similar purpose. Some antibiotic resistant bacteria- Pseudomonas aeruginosa, Staphylococus aureus and Escherichia coli isolated from cooking wares in homes were investigated using agar well diffusion and agar dilution method to test for the antibacterial activity of fresh Allium cepa (onion) extract. All were susceptible to the fresh white and red onion extract except Staphylococus aureus which was susceptible to only the white onion extract. The diameter of zones of inhibition ranged from 2 mm-35 mm. The Minimum Inhibitory Concentration (M. I. C.) and the Minimum Bacterial Concentration (M. B. C.) values of the fresh onion juices against the test bacteria were low ranging from 3.125% v/v – 25.0% v/v. This study indicates that the fresh raw extracts of Allium cepa possess significant antibacterial potency against these antibiotic resistant bacteria.

Appraisal of immediate and late effects of mobile phone radiations at 2100MHz on mitotic activity and DNA integrity in root meristems of Allium cepa.

The present study evaluated the potential of 2100MHz radiofrequency radiations to act as cytotoxic and genotoxic agent. Fresh onion (Allium cepa L.) roots were exposed to electromagnetic field radiations (EMF-r) for different durations (1h and 4h) and evaluated for mitotic index (MI), phase index, chromosomal aberrations, and DNA damage. DNA damage was investigated with the help of the comet assay by assessing various parameters like % head DNA (HDNA), % tail DNA (TDNA), tail moment (TM), and olive tail moment (OTM). Effects of EMF-r exposure were also compared with that of methyl methanesulfonate (MMS; 90μM), which acted as a positive control. The post-exposure effects of EMF-r after providing the test plants with an acclimatization period of 24h were also evaluated. Compared to the control, a significant increase in the MI and aberration percentage was recorded upon 4h of exposure. However, no specific trend of phase index in response to exposure was detected. EMF-r exposure incited DNA damage with a significant decrease in HDNA accompanied by an increase in TDNA upon exposure of 4h. However, TM and OTM did not change significantly upon exposure as compared to that of control. Analysis of the post-exposure effects of EMF-r did not show any significant change/recovery. Our data, thus, suggest the potential cytotoxic and genotoxic nature of 2100MHz EMF-r. Our study bears great significance in view of the swiftly emergent EMF-r in the surrounding environment and their potential for inciting aberrations at the chromosomal level, thus posing a genetic hazard.

Emission of volatile organic compounds from yellow onion (Allium cepa L.) bulbs during storage.

Fresh onions (Allium cepa L.) emit volatile organic compounds (VOCs) naturally in very low concentrations. The aim of the present study was to determine the emission rate of low-boiling VOCs from healthy and naturally infected onion bulbs at 4, 15, and 25°C and to evaluate the applicability of the VOC method to monitor quality changes during 12weeks of storage of two cultivars ('Hystand' and 'Hoza') of yellow onions. VOCs were extracted from the headspace of bulbs by solid phase micro-extraction (SPME) up to 5 times during storage and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of twenty-nine compounds were measured and twenty-seven of these were identified while thirteen were reported for the first time from yellow onion bulbs. Acetone (0.10-18.0nmolkg-1day-1), dimethyl disulfide (0.12-18.9nmolkg-1day-1) and hexanal (0.05-4.40nmolkg-1day-1) were among the most abundant volatiles emitted from healthy bulbs. The concentration of these compounds as well as the total volatiles decreased with time in storage. However, microbial infection resulted in higher emission of propene, carbon disulfide, isoprene, pentane, 2-methylfuran, 3-methylfuran, 1-propenethiol, hexane, and methyl propyl sulfide, indicating that VOC emission may be used as an indicator to monitor natural senescence and decay of stored onion bulbs.

Study of Four Onion Varieties Drying Kinetics in an Oven and a Solar Greenhouse

Onion production (Allium cepa L.) in Senegal reached 390 000 tons in 2016. Due to post-harvest losses, annual demand (150 000 and 250 000 tons) is being met through imports. This work consists in proposing a drying process at a lower cost to overcome this dependence and preserve the quality of the product. The optimization of local onion varieties drying in an oven and in solar greenhouse, as well as the physicochemical characterization of the products were carried out. The moisture of fresh onion bulb varies between 85.56 ± 0.60 and 89.13 ± 0.69 (%). To obtain a moisture £ 8.89 ± 0.16 (%) ensuring stability, the optimal drying conditions in the oven are 60° C / 6H (Galmi Violet) and 7H (Safari, Gandiol F1 and Orient F1). Under these conditions, the content of polyphenols in g equivalent of gallic acid / 100 g db increases (0.111 ± 0.0040 to 0.312 ± 0.0041 before drying, 0.546 g ± 0.0117 to 0.837 ± 0.0091 after drying). Optimum solar drying in a greenhouse is obtained between temperatures of 35 to 65° C / 8H-9H. From a perspective of sustainable development, the perspective is the modeling of drying kinetics in a solar greenhouse.

Determination of phytochemical properties of dried onion slices (Allium cepa L. var. Violet of galmi)

The high water content in fresh onion bulb make it difficult to preserve. In order to remedy these situation, it can be converted into dried slices. The objective of this work was to optimize the phenolic compounds and antioxidant properties of dried onion slice. Box Behnken design was performed to determine the effect of drying temperature (25–45 °C), water activity (0.2–0.6) and drying time (12–24 h) on the moisture content, total phenolic, flavonoids content, DPPH free radical scavenging and total reducing power on dried onion slice. Desirability was fixed to obtain the best possible combination of factors to a maximum values of total phenolic and flavonoids content, DPPH free radical scavenging, total reducing power and a low level of moisture content. Data analysis showed that the factors significantly (p < 0.05) affected the responses variables. Desirability function showed that the optimal dry conditions were 20 h for drying time, drying temperature of 28 °C and water activity of 0.48. At this optimum point the moisture content, polyphenol and flavonoids content, DPPH free radical scavenging and total reducing power were respectively: 9.53%, 1060.45 mg gallic acid/100 g DM; 342.61 mg quercetin/100 g DM; 52.18 mg Trolox/100 g DM and 78.14 mg Vitamin C/100 g DM. In this overall optimum point desirability was 0.9. No significant difference (p < 0.05) was found between the experimental and predicted values of the response variables at optimum point.

Influence of Pickling Process on Allium cepa and Citrus limon Metabolome as Determined via Mass Spectrometry-Based Metabolomics.

Brine, the historically known food additive salt solution, has been widely used as a pickling media to preserve flavor or enhance food aroma, appearance, or other qualities. The influence of pickling, using brine, on the aroma compounds and the primary and secondary metabolite profile in onion bulb Allium cepa red cv. and lemon fruit Citrus limon was evaluated using multiplex metabolomics technologies. In lemon, pickling negatively affected its key odor compound “citral”, whereas monoterpene hydrocarbons limonene and γ-terpinene increased in the pickled product. Meanwhile, in onion sulphur rearrangement products appeared upon storage, i.e., 3,5-diethyl-1,2,4-trithiolane. Profiling of the polar secondary metabolites in lemon fruit via ultra-performance liquid chromatography coupled to MS annotated 37 metabolites including 18 flavonoids, nine coumarins, five limonoids, and two organic acids. With regard to pickling impact, notable and clear separation among specimens was observed with an orthogonal projections to least squares-discriminant analysis (OPLS-DA) score plot for the lemon fruit model showing an enrichment of limonoids and organic acids and that for fresh onion bulb showing an abundance of flavonols and saponins. In general, the pickling process appeared to negatively impact the abundance of secondary metabolites in both onion and lemon, suggesting a decrease in their food health benefits.

A neutral Cu-based MOF for effective quercetin extraction and conversion from natural onion juice.

We report herein a new microporous neutral three-dimensional (3D) metal–organic framework [Cu2(L)(DMF)(H2O)]·guest (1·guest) composed of copper paddle-wheel and flexible tetracarboxylic acid linkers (DMF = N,N-dimethylformamide, H4L = tetrakis[(6-carboxynaphthoxy)methyl]methane). Surprisingly, this MOF with neutral cavities can not only extract pure quercetin (QT) but also convert it into Cu–QT during the desorption process. It has been well characterized by UV-vis, IR, ESI-MS and TEM-EDS studies. Moreover, it can efficiently extract natural product QT from fresh QT-rich onion juice and rapidly convert it into Cu–QT with a relatively high conversion rate.

Ancient whole grain gluten-free quinoa, high protein, vegetable flatbreads

The objective was to evaluate four kinds of ancient whole grain gluten-free Quinoa, high protein, vegetable, nutritious, tasty, health promoting flatbreads. The flatbreads were Quinoa Peanut Meal Kale (QPK), QPK-Onions, QPK-Garlic and QPK-Cilantro. Quinoa contains all the essential amino acids. Peanut Meal was utilized to formulate higher protein flatbreads and to add value to this low value farm byproduct. Fresh green leafy vegetable kale was used with health promoting potential as it binds bile acids. Onions, garlic and cilantro contain healthful phytonutrients. The level of fresh onions, garlic and cilantro were determined by consensus of the laboratory personnel. Flatbread dough was prepared using 50-67 ml water per 100g as is ingredients. The ingredients were Quinoa flour and Peanut Meal (39.4%) and fresh Kale (19.7%) as is basis. Onions, Garlic and Cilantro flatbreads contained 28%, 7% and 28% of the respective ingredients. 50g flatbread dough was pressed between parchment paper in tortilla flatbread press to about 17 cm circle. Flatbreads were cooked in flatbread cooker for 2-minutes at (165-195 oC). Seventy-one in-house volunteers evaluated Color/Appearance of the QPK, QPK-Onions and QPK-Garlic to be similar and significantly (P ≤ 0.05) preferred than QPK-Cilantro flatbreads. Odor/Aroma of QPK-Onions and QPK-Garlic flatbreads was similar and significantly higher than QPK and QPK-Cilantro. Texture/Mouth Feel of the QPK-Garlic flatbreads was judged significantly higher than QPK and QPK-Cilantro. Taste/Flavor and Acceptance of QPK-Onions flatbreads was significantly better than QPK and QPK-Cilantro. The acceptance of the flatbreads tested was QPK-Onions 92%, QPK-Garlic 89%, QPK 77% and QPK-Cilantro 72%. These flat breads used only 3-4 ingredients and could be made in any house kitchen or commercial production. These whole gain, high protein, gluten-free, vegetable, flatbreads offer tasty, nutritious and healthy choice to all and those sensitive to gluten.

Comparative study on the flavonoids extraction rate and antioxidant activity of onions treated by three different drying methods

Onions, rich in flavonoids, with antioxidant, antibacterial, and other biological activities, are often used as extraction of raw materials to obtain health products with high flavonoids content. However, the amount of raw material consumption is large due to low yield of extracts from fresh onions. As a result, dried onions often are used as extraction materials. The effects of air drying (AD), freeze-drying (FD), and microwave freeze-drying (MFD) on the flavonoids extraction yield of onions were investigated. The most effective and economical method was hot AD. On the other hand, the flavonoids extraction rate of onions dried by MFD was the fastest. FD could also obtain high extraction rate, but it cost the highest energy consumption. In order to obtain relatively rapid, economic, and effective extraction of onion flavonoids, onions can be dried by MFD or AD method.