Onion Juice Research Articles

Evaluation of analgesic and anti-inflammatory effects of fresh onion juice in experimental animals

Onion is a well known traditional medicinal plant that has been consumed for its putative nutritional and health benefits for centuries. This study was carried out to determine the possible analgesic and anti-inflammatory effects of fresh onion juice in experimental animals. Hot plate and formalin tests were used to study the analgesic effect of fresh onion juice in mice during acute and chronic pain stages modeling, respectively. The anti-inflammatory effect of fresh onion juice was assessed by applying carrageenan sub plantar injection to Sprague-Dawley rats. The obtained results illustrated a significant analgesic property for fresh onion juice in both pain phases compared with positive control group (Pv≤0.05); the effects were similar to that of morphine (5 mg/kg) as the standard treatment. In inflammation assessment, fresh onion juice was able to decrease the hind paw thickness significantly in comparison with control group (Pv≤0.001). In the mean time, it also demonstrated better results than the standard treatment, diclofenac with a 10 mg/kg dosage, (Pv≤0.05). It can be concluded that fresh juice of onion is capable of inhibiting both acute and chronic pain as well as inflammation, with a more strong effect towards inflammation. Key words: Allium cepa, analgesic, anti-inflammatory, hot plate test, formalin test, carrageenan test.

Biopreservation of 'Birgah' Eggplant from Polyphenol Oxidase Activity Assayed In Vitro with Onion (Allium Cepa L.) by-products

Eggplants are vegetables largely consumed in many recipes as fresh and whole product or, more recently, as minimally processed vegetable (MPV). The main issue in diced eggplant consists in the oxidation due to polyphenol oxidase (PPO, EC 1.14.18.1), an enzyme producing pigments responsible for the undesirable dark color which spoiled the product. The aim of this work was to study fresh or heat-treated (100 °C for 15 min) onion by-products (paste, juice and bagasse) in order to evaluate in vitro the PPO enzyme inhibition capacity in minimally processed eggplant cv. 'Birgah’. The heated onion juice was the most suitable anti-browning extract among all by-products tested, followed by pasteurised paste and fresh juice (54.2, 41.2 and 37.3 % reduction in PPO activity, respectively). Data suggested that the thermal treatment enhances the effects of the extracts probably due to a synergic action between some endogenous active compounds present in onion and Maillard reaction products obtained during heating.

Treatment Effects of Onion (Allium cepa) and Ginger (Zingiber officinale) on Sexual Behavior of Rat after Inducing an Antiepileptic Drug (lamotrigine).

The aim of the present study was to evaluate the beneficial degree of sexual behavior in male rats after inducement of onion and ginger in lamotrigine receiving groups. Wistar rats (n=70) (male=35, female=35) were allocated so that males were divided into seven groups: control (n=5) and test groups (n=35). Control group used normal Saline (3 cc for each rat). Lamotrigine group were given Lamotrigine (10 mg/kg). Onion group used onion fresh juice (3 cc for each rat/daily). Ginger group was fed on ginger powder (100 mg/kg/daily). Onion & Lamotrigine group used both onion juice (3 cc fresh onion juice for each rat/day) and Lamotrigine (10 mg/kg). Ginger & Lamotrigine group used both ginger powder (100 mg/kg/day) and Lamotrigine (10 mg/kg/day). Onion, ginger & Lamortigine group jointly used ginger powder (100 mg/kg/day) and onion juice (3 cc juice for each rat) and Lamotrigine (10 mg/kg/day). All groups were given treatments orally. For sexual behaviors, Estradiolbenzoate (50 microgram) and 6 hours before test (500 microgram) progesterone was injected to the female rats subcutaneously. Then rats were viewed for erection, ejaculation and cup. There was maximum Serum total testosterone level in the onion group, there was maximum malondialdehyde (MDA) in the Lamotrigine group and there was maximum total antioxidant capacity in both the onion group and ginger group (p<0.05). Results revealed that administration of (100 mg/kg/day) of ginger powder, and freshly prepared onion juice (3 cc for each rat), significantly lowered the adverse effects of lamotrigine, and can have beneficial effects on sexual behavior in male rat.

Attenuating effect of Allium ascalonicum L. on paracetamol induced seminal quality impairment in mice

Overdose and long term use of paracetamol caused testicular toxicity by its toxic oxidative metabolites. Red onion (Allium ascalonicum L.) bulbs are rich in quercetin, a strong antioxidant flavonoid which plays a crucial role in cell defense system against oxidative stress. The aim of this study is to determine the attenuating effect of A. ascalonicum juice on testicular toxicity induced by paracetamol (0.05 g/100 gBW) in male mice. Blood testosterone and seminal analysis were assessed for testicular toxicity. A significant decrement of blood testosterone and seminal quality impairment were found in groups which received paracetamol. Interestingly, both groups that pre-received A. ascalonicumjuice at dose 0.5 and 1.0 g/100 gBW for 4 days and concurrent received paracetamol for 14 days revealed a significant increase of blood testosterone and seminal quality improvement in all parameters by increasing total sperm counts, percentage of viable sperms and normal motile sperms, but decreasing percentage of abnormal morphology sperms when compared with the paracetamol treated group. These results indicated that administration of red onion juice can alleviate testicular toxicity induced by paracetamol. Key words: Allium ascalonicum L., paracetamol, seminal quality, testosterone.

Modulating effect of Allium cepa on kidney apoptosis caused by Toxoplasma gondii.

Toxoplasma gondii is a widespread protozoan parasite that infects a broad range of warm blooded animals as well as humans. The present study was investigated to evaluate the effects of allium cepa on renal failur in male rats which experimentally infected by Toxoplasma gondii, RH strain. Wistar male rat (n=40) were allocated into four groups, group one that received tachyzoites of T. gondii (ip) (n=10), group two that received tachyzoites of T. gondii (ip), plus fresh onion juice by gavages method (n=10), group three received just fresh onion juice by gavages method (n=10) and control group (n=10) that received nothing. Animals were kept in standard condition. In 30 day after inducing Toxoplasma infection, 5cc blood was collected for serum protein and TAC levels. Kidney tissues of Rat in whole groups were removed and prepared for apopetosis analysis. Serum protein and kidneys weights were significantly decreased in groups that were infected with T. gondii, in comparison to control and onions groups. Kidneys Apopetosis in toxoplasma group significantly increased in comparison to control group (P<0.05).level of TAC was significantly increased in groups that received onio juice (P<0.05). This study showed that T. gondii have significantly effect on serum protein and TAC, apopetosis and fresh onion juice returned and treated this harmful effect, so it is suggested that eating of onion is useful in toxoplasma infection.

Underestimation of Pyruvic Acid Concentrations by Fructose and Cysteine in 2,4‐Dinitrophenylhydrazine‐Mediated Onion Pungency Test

Onion pungency has been routinely measured by determining pyruvic acid concentration in onion juice by reacting with 2,4-dinitrophenylhydrazine (DNPH) since 1961. However, the absorbency of the color adduct of the reaction rapidly decreased in onion samples as compared to that of the pyruvic acid standards, resulting in underestimations of the pyruvic acid concentrations. By measuring the absorbency at 1 min, we have demonstrated that accuracy could be substantially improved. As a continuation, the causes of degradation of the color adduct after the reaction and pyruvic acid itself before the reaction were examined in this study. Alliinase action in juice (fresh or cooked) and bulb colors did not influence the degradation. Some organic acids indigenously found in onion, such as ascorbic acid, proline, and glutamic acid, did not reduce the absorbency. However, fructose within the onion juice or supplemented caused the degradation of the color adduct, whereas sucrose and glucose had a lesser effect. Degradation rates increased proportionally as fructose concentrations increased up to 70 mg/mL. Cysteine was found to degrade the pyruvic acid itself before the pyruvic acid could react with DNPH. Approximately 90% of the pyruvic acid was degraded after 60 min in samples of 7 mM pyruvic acid supplemented with 10 mg/mL cysteine. Spectral comparisons of onion juice containing fructose naturally and pyruvic acid solution with supplemented fructose indicated identical patterns and confirmed that the color-adduct degradation was caused by fructose. Our study elucidated that fructose, a major sugar in onion juice, caused the degradation of color adduct in the onion pungency test and resulted in underestimation of the pyruvic acid concentration.

Improved Consistency in DNPH‐Mediated Pyruvic Acid Analysis of Onion Juice by Modifying the Sample Processing Order

Onion pungency is commonly measured on absorbency of the wine pink color that results from adding NaOH to the heated mixture of dinitrophenylhydrazine (DNPH) and onion juice. However, significant variation exists among several modifications of the original Schwimmer and Weston (SW) method. We observed differences in pyruvic acid concentrations of 20%-30% between our automated method and a batch method with manual absorbency readings. To determine the source of the differences, we examined the heating time and waiting time of the sample-DNPH mixtures and found no differences. The differences were caused by differential color degradation between the pyruvic acid standards and onion juice samples. These differences could be minimized by reading the absorbency within 1 min of NaOH addition. Using this information, we devised the one-by-one method to control the reading time at 30 s. We compared 5 different analysis methods of 40 onion samples representing 4 onion colors. The automated, high-performance liquid chromatography, and SW methods had similar results, with only about a 5% difference. However, the batch method resulted in differences of approximately 24% as compared to the automated method. The one-by-one method produced very comparable results, within 5%, to the automated method. By modifying the procedure to ensure a uniform and fast reading time, we increased the consistency between the pungency analysis methods. Therefore, fast and uniform absorbency reading time is essential for an accurate measurement of pungency in undiluted onion juice.

가축용 생균제 Lactobacillus plantarum을 이용한 양파즙 발효의 균체성장과 항산화 활성

This study was conducted to establish the optimal medium condition for the animal probiotic Lactobacillus plantarum by using onion juice. Cell yield and antioxidant activity increased in proportion to high additive levels of onion juice in medium. Onion juice, sucrose and yeast extract were selected as media ingredient factors and the effects of their mixed ratio in medium were evaluated. The full factorial design consisted of 24 experimental runs and was employed to estimate the main effects of the factors and their interactions. Significant positive effects on cell yield and antioxidant activity was shown with yeast extract and onion juice, respectively. Significant interaction was found only between sucrose and yeast extract in antioxidant activity. Finally, we selected an optimal medium that was composed of (g/l) onion juice, 600; sucrose, 15; yeast extract, 5. The efficiency of this optimum medium was estimated by using a 5 l jar fermenter. As a result, the maximum cell yield was (CFU/ml) at 12 hr. Cell yield at the end of incubation (20 hr) was (CFU/ml) and it was very similar with the predicted value, (CFU/ml). Antioxidant activity of culture was maintained at about 60~65% during all incubation time, resulting in a higher-than-predicted activity of 47.1%.

DEVELOPMENT AND OPTIMISATION OF AMPEROMETRIC BIOSENSORS FOR IMPROVED POSTHARVEST QUALITY CONTROL

Until now the main impact of biosensors has been in the medical diagnostics field for monitoring glucose levels in blood. However, the demand for reliable and inexpensive methods for the assessment of fresh produce quality is set to expand; biosensors offer a viable opportunity to fulfil this niche. This study reports on two biosensor systems for the rapid determination of pungency in onion bulbs, and glucose in both onions and strawberry fruit. Accordingly, disposable prototype biosensors were constructed and optimised using pyruvate oxidase (PyOx) and pyruvate dehydrogenase (PDH) or glucose oxidase (GOx) immobilised onto Meldolas Blue screen printed electrodes. The mediated biosensors operated at low operating potentials (+0.05; +0.150 and 0.30V (versus Ag/AgCl)) which is favourable for minimising positive bias encountered from potential interferents within fresh produce matrices (viz. ascorbic acid and phenylpropanoids). The response of the pyruvate-based biosensors showed a strong correlation with untreated onion juice of known pyruvate concentration ranging from 2-12 μmol/g fresh weight (FW) and thus enabled rapid discrimination between low and high pungency onions. Similarly, GOx-based biosensors were able to measure glucose in real strawberry and onion juices. Unlike total soluble solids (TSS), and as hypothesised, the GOx biosensors, under different operating conditions, were able to discriminate and rank different strawberry and onion cultivars based on their glucose content when compared to known concentrations measured by HPLC (R 2 >0.73; P<0.001). The results from this study demonstrated the possibility of replacing standard techniques that are either time consuming (viz. colorimetric assay for determining pyruvate concentration in onions) or poorly correlated with the real composition of the samples (viz. total soluble solids determination in onions and strawberry fruits) with a more rapid method using screen-printed mediated amperometric biosensors. The introduction of biosensors for specific target analytes in fresh produce will empower growers to undertake their own QC rather than outsourcing analysis.

Identification of Candidate Amino Acids Involved in the Formation of Pink‐Red Pigments in Onion (Allium cepa L.) Juice and Separation by HPLC

The formation of pink-red pigments ("pinking") by various amino acids was investigated by reacting amino acids with compounds present in onion juice. The unknown pink-red pigments were generated and separated using high-performance liquid chromatography (HPLC) and a diode array detector (DAD) in the range of 200 to 700 nm. To generate pink-red pigments, we developed several reaction systems using garlic alliinase, purified 1-propenyl-L-cysteine sulfoxide (1-PeCSO), onion thiosulfinate, natural onion juice, and 21 free amino acids. The compound 1-PeCSO was a key compound associated with pinking in the presence of both the alliinase and amino acids. Numerous naturally occurring pink-red pigments were detected and separated from pink onion juice using the HPLC-DAD system at 515 nm. Most free amino acids, with the exceptions of histidine, serine, and cysteine, formed various pink-red pigments when reacted with onion thiosulfinate. This observation indicated that onion pinking is caused not by a single pigment, but by many. Furthermore, more than one color compound could be produced from a single amino acid; this explains, in part, why there were many pink-red compound peaks in the chromatogram of discolored natural onion juice. We presumed that the complexity of the pink-red pigments was due to the involvement of more than 21 natural amino acids as well as several derivatives of the color products produced from each amino acid. We observed that the pinking process in onion juice is very similar to that of the greening process in crushed garlic, emphasizing that both thiosulfinate from flavor precursors and free amino acids are absolutely required for the discoloration.

THE EFFECT OF GARLIC OR ONION MARINADE ON THE LIPID OXIDATION AND MEAT QUALITY OF PORK DURING COLD STORAGE

ABSTRACT Fresh semimembranosus pork was marinated with garlic or onion juice to determine their effect on lipid oxidation and meat quality during cold storage. Five marinade treatments, which include control (C) and two levels (3 and 6%) of garlic juice (GJ) or onion juice (OJ), were prepared and stored for 7 days at 4C. pH, color, thiobarbituric acid reactive substances (TBARS) values, peroxide value (POV) and sensory evaluations of meat were determined at 1, 3 and 7 days of storage. The pH value of GJ and OJ were higher than control during 7 days of storage at 4C, and control had the lowest pH value. The marinated samples had significantly lower Hunter lightness and yellowness values than control (P &lt; 0.05). The TBARS values of all pork samples increased during cold storage and this increase is greater if it is not any garlic and onion treatment (control). The pork marinated with 6% GJ showed the lowest TBARS value (P &lt; 0.05), and pork marinated with 6% garlic or onion juice had significantly lower TBARS values than those with 3%. Also, 6% OJ sample reached lesser increase of TBARS than any treatment in 7 days of storage. All treatment samples increased POV values in 7 days storage (P &lt; 0.05). The panelists also recorded higher sensory scores to the samples with marinated garlic and onion juice (P &lt; 0.05). Sensory evaluations indicated that all marinated pork sample with garlic and onion juice had significantly higher tenderness and flavor attributes than control (P &lt; 0.05).PRACTICAL APPLICATIONSOur results show that garlic and onion juice is recommended to improve sensory evaluation and antioxidant effect in marinated pork. Therefore, it is suggested that garlic and onion juice could be used to extend the shelf life of meat products, providing the consumer with meat containing natural additives, which might be seen as more healthful.

Fruits and vegetables protect against the genotoxicity of heterocyclic aromatic amines activated by human xenobiotic-metabolizing enzymes expressed in immortal mammalian cells

Heterocyclic aromatic amines (HAAs) can be formed during the cooking of meat and fish at elevated temperatures and are associated with an increased risk for cancer. On the other hand, epidemiological findings suggest that foods rich in fruits and vegetables can protect against cancer. In the present study three teas, two wines, and the juices of 15 fruits and 11 vegetables were investigated for their protective effect against the genotoxic effects of 2-amino-3-methylimidazo[4,5- f]quinoline (IQ) and 2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP). To closely mimic the enzymatic activation of these HAAs in humans, genetically engineered V79 Chinese hamster fibroblasts were employed that express human cytochrome P450-dependent monooxygenase (hCYP) 1A2 (responsible for the first step of enzymatic activation) and human N( O)-acetyltransferase (hNAT) 2*4 or human sulfotransferase (hSULT)1A1*1 (responsible for the second step of enzymatic activation): V79-hCYP1A2-hNAT2*4 for IQ activation and V79-hCYP1A2-hSULT1A1*1 for PhIP activation. HAA genotoxicity was determined by use of the comet assay. Black, green and rooibos tea moderately reduced the genotoxicity of IQ (IC 50 = 0.8–0.9%), whereas red and white wine were less active. From the fruit juices, sweet cherry juice exhibited the highest inhibitory effect on IQ genotoxicity (IC 50 = 0.17%), followed by juices from kiwi fruit, plum and blueberry (IC 50 = 0.48–0.71%). The juices from watermelon, blackberry, strawberry, black currant, and Red delicious apple showed moderate suppression, whereas sour cherry, grapefruit, red currant, and pineapple juices were only weakly active. Granny Smith apple juice and orange juice proved inactive. Of the vegetable juices, strong inhibition of IQ genotoxicity was only seen with spinach and onion juices (IC 50 = 0.42–0.54%). Broccoli, cauliflower, beetroot, sweet pepper, tomato, chard, and red-cabbage juices suppressed IQ genotoxicity only moderately, whereas cucumber juice was ineffective. In most cases, fruits and vegetables inhibited PhIP genotoxicity less strongly than IQ genotoxicity. As one possible mechanism of antigenotoxicity, the inhibition of activating enzymes was studied either indirectly with diagnostic substrates or directly by measuring CYP1A2 inhibition. Only sour cherry, blueberry, and black currant juices suppressed the first step of HAA enzymatic activation, whereas most plant-derived beverages inhibited the second step.

EFFECT OF ONION (ALLIUM CEPA L.) EXTRACT ON MICROBIOLOGICAL QUALITY OF REFRIGERATED BEEF MEAT

ABSTRACT The effect of onion (Allium cepa L.) extract on the fresh beef fillet meat was investigated. Beef fillet samples were cut into pieces and treated with 5, 10, 20 and 50 % onion‐water extract (v/v) and stored in refrigeration conditions at 4C. Microbiological quality of the samples was investigated during storage for (0, 1, 3, 6 and 9) 9 days. Increasing concentrations of onion extract significantly affected Escherichia coli and yeast‐mould counts (P &lt; 0.05, P &lt; 0.01); Pseudomonas spp., aerobic mesophilic bacteria and total coliforms were not affected significantly (P &gt; 0.05) for some concentrations and days. The count of bacteria of the samples reached and exceeded the spoilage limit after 9 days at 4C. High concentrations of onion extract were effective in protecting beef meat, depending on the reduction of some microbial contaminations.PRACTICAL APPLICATIONSThe effects of onion extracts on beef meat microbial spoilage were evaluated. Microbial spoilage of meat is an important factor influencing consumer health directly as well as influencing the cost and food availability. Antimicrobial activity of onion juice in different researches was previously reported. In this study, onion extract reduces some microbial contamination of beef fillet meat by inhibiting Escherichia coli and yeast‐mould counts during 9 days at refrigeration conditions. Onion extract can find applications especially with service preservation of meat meals, with the aid of refrigeration, which is also prepared with onion flavor (döner kebap, meat balls, cig köfte, etc.).

양파즙 첨가 식빵의 특성과 저장 효과

양파즙을 추출하여 수분과 설탕비를 맞추어 수분함량대비 0%, 3%, 6%, 9%, 12%, 15%를 첨가하여 식빵을 제조하였다. 식빵의 무게, 부피 및 비용적은 양파즙 첨가량이 증가할수록 증가하였고, 굽기손실율은 양파즙 첨가량이 증가할수록 낮아졌다. 색도를 측정한 결과 양파즙 첨가량이 증가할수록 백색도(L 값)는 낮게 나타났으며, 적색도 (a값)와 황색도 (b값)는 양파즙 첨가량이 많을수록 높게 나타났다. 양파즙 첨가 식빵의 pH 결과는 저장 기간 동안 감소하였으며, 무첨가군이 가장 높게 나타났고 양파즙 첨가 식빵이 낮게 나타났다. 경도를 측정한 결과 양파즙을 첨가할수록 낮았으며 무첨가군이 높게 나타났다. 저장기간이 경과함에 따라 경도는 증가하였으며 무첨가군이 양파즙 첨가군에 비해 급격하게 증가하였다. 저장기간이 경과함에 따라 수분활성도는 감소하였으나 양파즙 첨가식빵이 무첨가군에 비해 높았으며 호기성균과 곰팡이균의 변화 또한 저장기간이 증가할수록 균수는 증가하였다. 관능평가 결과 맛, 향, 표면상태, 식감, 종합적인 기호도에서 무첨가군과 유의적인 차이는 없었으나 3% 첨가군이 가장 높게 평가되었다. 관능결과로부터 양파즙 3<TEX>${\sim}$</TEX>5% 를 첨가하는 것이 최적의 범위로 판단되었고 양파즙을 첨가함으로 인해 건강, 기호성 식품일 뿐만 아니라 제품의 저장기간도 연장시켜주는 것으로 확인되었다. The characteristics and preservation of plain bread with 0, 3, 6, 9, 12 and 15% of onion juice added were investigated during storage at room temperature. The weight, volume and specific volume of bread with added onion juice increased, compared to those of the control bread. The color value of bread when onion juice was added had lower values of lightness and higher values of redness and yellowness than those of the control bread. The pH was lower in the bread during storage, and it decreased with an increase of onion juice. Hardness was increased and water activity was decreased in the bread during storage. With an increment of onion juice, hardness was the lowest but water activity was the highest. The addition of onion juice also inhibited the growth of aerobic bacteria and mold on bread. Taste, flavor, surface, texture and overall acceptability by sensory evaluation were the best when 3% of onion juice was added, but there were no significant differences between it and 0% bread. The results imply that addition of onion juice into plain bread will create a healthy and functional bread with an extended shelf-life.

Effects of Onion Juice Administration on Electrocardiogram in Dogs

Effects of Onion Juice Administration on Electrocardiogram in Dogs

Preventive effect of onion juice on selenite-induced experimental cataract

Purpose:To evaluate the effects of onion juice on sodium-selenite induced cataract formation.Materials and Methods:Thirty-two 10-day-old Wistar-albino rat pups were divided into four equal groups. Group 1 received only subcutaneous saline injection. In Group 2, sodium-selenite (30 nmol/g body weight) was injected subcutaneously. In Group 3, subcutaneous sodium-selenite was injected and one drop 50% diluted fresh juice of crude onion was instilled every 8 h into the right eye for 14 days; the left eye received no treatment. Group 4 rats were similar to those of Group 3, the only difference being that of undiluted fresh juice of crude onion. The development of cataract was assessed. Rat lenses were analyzed for total antioxidant (TA) level, and for activities of glutathione peroxidase (GPX) and superoxide dismutase (SOD).Results:Both eyes of all rats in Group 1 did not exhibit cataract formation. In Group 2, all rats developed Grade 3 cataract in the lenses of both eyes. The difference in exhibited cataract in the lens of the right eyes in all rats between Group 2 and any eyes of groups 3 or 4 were significant (P = 0.001). The mean TA level and mean activities of SOD and GPX in Group 2 rat lenses were significantly lower than the values in lenses of all rats in Group 1 (P = 0.001, 0.003, 0.001), and in the lenses of the right eyes of rats in Groups 3 and 4 (P = 0.001, 0.020, 0.001).Conclusion:Instillation of onion juice into the rat eyes can effectively prevent selenite-induced cataract formation. This effect was associated with increased TA level, SOD and GPX activities in the lens.

Biologically active compounds from different herbs used as additives in honeybee feeding.

Different herb preparations (alcoholic extracts and water infusions) were tested for total phenol and flavonoid content and antioxidant properties. The Folin Ciocalteu test was used to determine the phenol content, Kim method with some modifications was used for total flavonoid content and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay for radical scavenging activity. Sugar profile for herb preparations was determined by HPLC with refractive index detection. The highest content of total polyphenols was registered in fresh nettle infusion (689 mgGAE/100g DW sample), followed by PROTOFIL (570 mgGAE), infusion of Echinacea (570 mgGAE), thyme extract (555 mgGAE), Echinacea extract (549 mgGAE), thyme infuzion (530 mgGAE), dry nettle infuzion (510 mgGAE) and fresh nettle extract (426,7 mgGAE). Smaller quantities were registered for dry nettle extract and fresh juice of onion. Regarding the flavonoid content, higher quantities were registered for fresh nettle infusion (668 mgQE in 100 g DW sample), followed by dry nettle infusion (482 mgQE), PROTOFIL (378,9 mgQE), fresh nettle extract (368 mgQE) and Echinacea infusion (326 mgQE). Smaller quantities were obtained for Echinacea, thyme, dry nettle extract and thyme infusion (183–123 mgQE). Antioxidant activity was not correlated with total polyphenols and flavonoid content, the highest antioxidant activity being registered in fresh juice of garlic and onion (95,1% and 84,85% inhibition of DPPH radical). High percentages of inhibition present the extracts and infusions of every analised plants (50,7% - 75,47%), exception was registered in onion and garlic extracts, which inhibit the DPPH radical in proportion of 29,84% and 20,98% respectively

2단계 발효에 의한 양파식초 제조의 최적 조건 검토

본 연구는 양파즙으로 식초를 생성하기 위해 수행되었다. 양파는 당, 아미노산, 다양한 영양분이 풍부하기 때문에 식초의 우수한 원료로 고려된다. 초산발효를 위해 초산균은 시판되고 있는 식초와 완숙된 김치로부터 분리하여 사용하였다. 양파즙 배지에 2-8% ethanol이 보충될 때, 4% ethanol 첨가에 의해 9일에 가장 높은 초산 생성능을 보였다. 초산 생성을 위한 적정온도는 <TEX>$30^{\circ}C$</TEX>였고, 통기량은 200 rpm이 경제적인 것으로 나타났다. 초산 발효를 위해 표면적인 넓은 삼각 플라스크가 시험관보다 높은 생성 능력을 보였다. 그러므로 초산 생성을 위한 초적 조건은 초기 5% 알코올 함량과 2% 산도로, <TEX>$30^{\circ}C$</TEX>에서 200 rpm으로 9일 동안 배양하는 것으로 나타났다. 이 조건으로 초산 발효될 때, 5.2% 총산도와 1% 미만의 알코올이 잔존하는 것으로 나타났다. 이것은 산업자원부가 고시한 과실 음료 조건에 적합한 것으로 판명되었다. This study was carried out to develop a vinegar by an onion juice. Onions are considered to be a promising source of the vinegar because these are rich in sugars, amino acids and various nutrients. An Acetobacter for an acetic acid fermentation was isolated and used from vinegars produced by industrial goods or from matured Kimchi. When supplemented with 2-8% ethanol into an onionic juice medium, the highest production of the acetic acid was observed at 9 days by addition of 4% ethanol. Optimum temperature and aeration for acetic acid production were exhibited at <TEX>$30^{\circ}C$</TEX> and 200 rpm, respectively. A flask containing larger air-contact surface region for fermentation was produced the more acetic acid than that of a test tube. Taken all these together, an optimum condition for the acetic acid fermentation was over 9 days at <TEX>$30^{\circ}C$</TEX>, 200 rpm with 5% alcohol and 2% initial acidity. When fermented by the upper condition, the final product contains 5.2% total acidity and less than 1% ethanol. These are suitable for conditions of fruit vinegar notified by the Ministry of Commerce, Industry and Energy.

Valorization of onion waste and by‐products: MCR‐ALS applied to reveal the compositional profiles of alcoholic fermentations of onion juice monitored by near‐infrared spectroscopy

The overall purpose of the project, of which this study is a part, was to examine the feasibility of onion waste as a support-substrate for the profitable production of food-grade products. This study focused on the efficient production of ethanol from worthless onions by transforming the onion juice into onion liquor via alcoholic fermentation with the yeast Saccharomyces cerevisiae. The onion bioethanol produced could be later used as a favorable substrate for acetic fermentation to finally obtain onion vinegar. Near-infrared spectroscopy (NIRS), coupled with the multivariate curve resolution-alternating least squares (MCR-ALS) method, has been used to reveal the compositional and spectral profiles for both substrates and products of alcoholic fermentation runs, that is, total sugars, ethanol, and biomass concentration. The ambiguity associated with the ALS calculation was resolved by applying suitable inequality and equality constraints. The quality of the results provided by the NIR-based MCR-ALS methodology adopted was evaluated by several performance indicators, including the variance explained by the model, the lack of fit and the agreement between the MCR-ALS achieved solution and the results computed by applying previously validated PLS reference models. An additional fermentation run was employed to test the actual predictive ability of the ALS model developed. For all the components resolved in the fermentation system studied (i.e., total sugars, ethanol, and biomass), the final model obtained showed a high predictive ability and suitable accuracy and precision, both in calibration and external validation, confirmed by the very good agreement between the ALS responses and the reference values (the coefficient of determination was, in all cases, very close to 1, and the statistics confirmed that no significant difference was found between PLS reference models and the MCR-ALS methodology applied). Thus, the proven reliability of the MCR-ALS model presented in this study, based only on NIR measurements, makes it suitable for monitoring of the key species involved in the alcoholic fermentation of onion juice, allowing the process to be modeled and controlled in real time.

Co-digestion of onion juice and wastewater sludge using an anaerobic mixed biofilm reactor

The co-digestion of onion juice and aerobic wastewater sludge produced from an onion processor using an anaerobic mixed biofilm reactor (AMBR) was investigated for biogas energy production potential and waste treatment. Two experiments were conducted to study the performance of an AMBR at different organic loading rates (OLRs) using different mixtures of onion juice and aerobic sludge. In the first experiment, the OLR was increased from 1.24 to 4.37 gVS/L/d by increasing the amount of onion juice in the feed mixture while maintaining a constant amount of aerobic sludge. When the OLR reached 4.37 gVS/L/d, the AMBR failed as indicated by decreased biogas production and pH. Increase of carbon to nitrogen ratio (C/N) from 13.7 to 20.3 and lack of proper alkalinity were suspected to be the causes for the failure. In the second experiment, the C/N of the feed mixture was maintained at about 15 while the OLR was increased from 1.40 to 3.60 gVS/L/d. The digester showed stable performance. The average biogas and methane yields of the two experiments were 0.62 ± 0.05 L/gVS and 0.37 ± 0.08 L/gVS, respectively. It was concluded that the C/N of about 15 was recommended for treating the mixture of onion juice and aerobic sludge.