Date Syrup Research Articles

Study on LOD of Chinese Honey Adulterated with HFCS by HPAEC-PAD

In consideration of the adulterated situation and characteristics of Chinese honey market, high performance anion exchange chromatography-pulsed amperometric detection (HPAEC-PAD) used for detection of high fructose corn syrup (HFCS) in adulterated honey were further studied in this paper, Isocratic elution with optimize chromatographic conditions, the limit of detection (LOD) of HFCS in adulterated acacia honey, linden honey, date honey and citrus honey can reached 1% respectively, while performed good reproducibility and high stability. This method was simple, effective, high sensitivity, and can be widely applied to the detection of honey with HFCS.

Effect of gum tragacanth on rheological and physical properties of a flavored milk drink made with date syrup

Date syrup as a nutritional additive and safe alternative to added sugar is one of the best choices for milk flavoring. In this study, a flavored milk beverage was formulated using date syrup for flavoring the product and gum tragacanth to obtain an acceptable mouth feel. Steady shear and dynamic oscillatory rheological properties of the samples contained 3 concentrations (0, 0.1, 0.2, and 0.3%, wt/wt) of 2 types of gum tragacanth (Astragalus gossypinus and Astragalus rahensis) which at 3°C, were studied. Particle size distribution and colorimetric assays were determined by laser diffractometry and using reflection spectrometer, respectively. Sensory analysis was performed with 25 semitrained panelists, using a 5-point hedonic scale. The results showed that viscoelastic properties, flow behavior parameters, particle size, and color parameters (L*, a*, and b*, where L* represents lightness, a* represents the redness/greenness quality of the color, and b* represents the yellowness and blueness quality of the colors) were significantly affected by the concentration of the gum tragacanth and the severity of this effect was influenced by the type of gum. The use of appropriate type and concentration of gum tragacanth in date milk formulation can improve the texture and mouth feel by affecting on particle size and the flow behavior of this product.

Effect of concentration temperature on some bioactive compounds and antioxidant proprieties of date syrup

The effect of the concentration temperature on the antioxidant activity, carotenoid and phenolic compounds of date syrup was investigated. Date juice was concentrated at 100 and at "60 in vacuum". After concentration, total phenolic, tannin, non-tannin, flavonoid and carotenoid content were determined spectrophotometrically and high-performance liquid chromatography was used for determination of 5-Hydroxymethyl-2-furfuraldehyde content. The antioxidant activity of date syrup was evaluated by various antioxidant methods including total antioxidant, 2,2-diphenyl-1-picrylhydrazyl free radical scavenging test, ferric reducing antioxidant power and β-carotene bleaching. All date syrups showed strong antioxidant activity accompanied by high total phenolic contents. Results showed that concentration at 100 significantly enhanced the antioxidant activities and total phenolic contents of date syrups compared to vacuum concentration at 60 . A good correlation between the antioxidant activity and total phenolic content and flavonoid was observed.

Determination of Flavonoids, Phenolic Acids and Abscisic Acid in Honeys of Different Floral Origins by HPLC

Flavonoids(rutin,myricetin,quercetin,naringenin,luteolin,keampferol and apigenin),phenolic acids(gallic acid,catechin,caffeic acid,α-catechin,p-coumaric acid,ferulic acid and 3,4-dimethoxycinnamic acid) and abscisic acid in honeys of different floral origins(lichee honey,longan honey,loquat honey,linden honey,date honey,lenourus honey,osmanthus honey,and Chinese milk vetch honey) were analyzed by HPLC-PDA.There were significant differences in the contents of abscisic acid among different samples.Abscisic acid content was ranged from 16.4 μg/100 g(osmanthus honey) to 1321.9 μg/100 g(lichee honey).Total phenolic contents of eight honey samples varied from 325.3 to 2260.8 μg/100 g honey.Among them,keampferol was be detected only in longan honey,loquat honey,lichee honey,date honey and Chinese milk vetch honey.Lichee honey contained the highest amount of ferulic acid,myricetin and quercetin.However,α-catechin was the main component in loquat honey.Longan honey contained a considerable amount of 3,4-dimethoxycinnamic acid,p-coumaric acid and luteolin.These results show that the profile of flavonoids,phenolic acids and abscisic acid could be used for authenticating the floral origin of a honey sample.

English

The present study was an illustrative investigation on L-glutamic acid production by usingCorynebacterium glutamicum employing a cheaply available dates syrup. Owing to the high sugar content of dates syrup (total sugar 80%) attempt was made to utilize the date syrup for the production of glutamic acid, in shaking culture. The acid treated dates syrup (ATDS) at concentration of 100g/L was the best sugar sources in the glutamic production. Penicillin addition at concentration of 4 U/ml after 12 h of incubation was superior in glutamic acid production. The selected temperature-sensitive mutants M5AJ2, showed 13.4% increase in glutamic production while, M5AJ4 and M7AJ6 showed 22.4 and 4.6% decrease respectively, in their glutamic acid production than their wild type bacterial strain. The specific production rate of glutamic acid in case of temperature shift-up from 31 to 39°C increased apparently 2 and 1.5 fold respectively on average from that under the constant temperature. 24g/L pure glutamic acid were precipitated in crystal at pH 3.2.   Key words: Glutamic acid, Corynebacterium glutamicum, dates syrup, fermentation, penicillin, mutation, UV, efflux.

Date fruit: chemical composition, nutritional and medicinal values, products

Date fruit has served as a staple food in the Arab world for centuries. Worldwide production of date fruit has increased almost threefold over the last 40 years, reaching 7.68 million tons in 2010. Date fruit can provide many essential nutrients and potential health benefits to the consumer. Date fruit goes through four ripening stages named kimri, khalal, rutab and tamer. The main chemical components of date fruit include carbohydrates, dietary fibre, enzymes, protein, fat, minerals, vitamins, phenolic acids and carotenoids. The chemical composition of date fruit varies according to ripening stage, cultivar, growing environment, postharvest conditions, etc. The nutritional and medicinal activities of date fruit are related to its chemical composition. Many studies have shown that date fruit has antioxidant, antimutagenic, anti-inflammatory, gastroprotective, hepatoprotective, nephroprotective, anticancer and immunostimulant activities. Various date fruit-based products such as date syrup, date paste, date juice and their derived products are available. Date by-products can be used as raw materials for the production of value-added products such as organic acids, exopolysaccharides, antibiotics, date-flavoured probiotic-fermented dairy produce, bakery yeasts, etc. In this paper the chemical composition and nutritional and medicinal values of date fruit as well as date fruit-based products are reviewed.

Rapid high-throughput assay to assess scavenging capacity index using DPPH

A new microplate-adapted DPPH rapid assay was developed to assess the antioxidant capacity of pure compounds and foods. The assay was carried out in buffered medium (methanol: 10mmol/l Tris buffer pH 7.5, 1:1 v/v) and reaction was completed at 10min. The scavenging capacity index (SCI), a theoretical antioxidant parameter directly related to the antioxidant capacity of samples, was calculated. SCI for pure compounds: gallic acid (6.76±0.08), quercetin (7.89±0.24), catechin (6.05±0.23), trolox (2.32±0.03), ascorbic acid (2.52±0.15) and gluthatione (1.08±0.08) and foods (μmol DPPH scavenged/100ml): tropical juice (655.62±12.18), mediterraneo juice (702.87±11.13), apple juice (212.52±17.22), pomegranate juice (319.83±9.45), red grape nectar (1093.05±18.69), Don Simon orange juice (632.94±17.22) and date syrup (15992.34±250.7) were comparable to those in previous reports using the classic DPPH assay. The relative standard deviation (RSD) for the SCI on the same and different days was less than 8.12% in all cases.

CFD modeling to predict diffused date syrup yield and quality from sugar production process

In this study, diffusion process of sugar from date is modeled using a commercial computational fluids dynamics (CFD) code FLUENT 6.3.23 (Fluent Inc., USA). A two phases CFD model was developed using an Eulerian–Eulerian approach to calculate the date volume fraction transferred during time from date phase to water phase. The diffusion process was studied as function of three date varieties (Manakher, Lemsi and Alligue), three speeds of agitation (0, 50 and 100rpm) and three date/water ratio (0.25, 0.50 and 0.75). The results revealed that, for mass transfer, the numerical data were in good agreement with the experimental data indicating the R2 of 0.84. Using a Lemsi date variety, the optimal condition of diffusion were 50rpm and 0.75 for speed of agitation and date/water ratio respectively.

Development of bacoside enriched date syrup juice and its evaluation for physical endurance.

Bacoside rich juice (BRJ) was developed using date syrup as base. BRJ was evaluated for physicochemical, sensory attributes and its effect on physical endurance. Overall acceptability of BRJ and date syrup juice (DSJ) was good according to hedonic scale/ratings. Twenty four adult male Wistar rats were divided into 4 groups (n = 6). Sedentary (Group I) and control (Group II) group rats were allowed to drink water whereas DSJ and BRJ group rats were provided free access to drink DSJ (Group III) and BRJ (Group IV) for 14days and were subjected to weight-loaded forced swim test (WFST) for every alternate day in order to evaluate the physical endurance. Both BRJ and DSJ group rats swimming efficiency was improved by 3 and 2 folds respectively in comparison with control group on day- 15. Improved physical endurance in BRJ group is due to reduced malondialdehyde levels in brain, liver and muscle tissues by 16.50%, 17.88% and 30.20%, respectively, compared to DSJ group (p < 0.01). In addition, administration of BRJ significantly protected the hepatic and muscle glycogen levels and reduced the levels of lactic acid in comparison to DSJ group. Hence, the present study clearly indicates that BRJ is an effective anti-fatigue drink ameliorates the various impairments associated with physical endurance.

PROCESSING OF DATE HONEY

Taking into consideration the high annual production rates of dates in Egypt and in a trial to magnify the economical value of its second degree this work was designed to study the availability of processing two dates varieties namely egyptian Siwy dates and Iraqi Zahdy dates for the production of quality Date honey with out adding any additives or preservatives and use this honey in manufacturing biscuits by replacing sugars by Date honey (Dibs). Two extraction methods were applied. In the first method (І), the extraction was done by adding hot water (80 – 90°C), to date flesh at W/D ratio 1.5:1 (w/w) respectively, followed by extraction, guise filtration and concentration, while in the second extraction method, hot water ( 70 °C) was added to date flesh at ratio of 3:1 respectively followed by extraction and concentration process. The syrup obtained in each method was packed and evaluated for its physical and chemical characteristic and compared with the local market syrup. The obtained data revealed that moisture, total sugars, crude proteins, fat and ash content of Siwy and Zahdy date syrup were as follow: 28.00-29.00 %, 69-68%, 1.2-1.4%, 0.5-0.4%and 1.3-1.2%, respectively for the syrup extracted by the first method. The same criteria but for the second extraction method of Siwy and Zahdy date syrup were as follows: 25.00-24.80%, 72.00-72.20%, 1.2-1.4%, 0.50-0.40%, and 1.30-1.20% respectively. The results of this study showed that filtration of date juice after extraction lead to improving date syrup color; this is due to removing the non soluble solids also the results showed that date syrup crop output was increased at 3:1 W/D ratio. Biscuits made using Siwy date syrup by replacing sugar by it at ratios of 10%, 20% and 30% compared with control (100% sugar), showed that sample manufactured by (70% sugar + 30% Siwy date syrup) recorded the highest total score and over acceptability value. It also recorded the highest appearance, shrinkage, taste and odor, while the control was the best value of crispiness only.

Evaluation of rheological properties of date syrup

Rheological behavior of date syrup is an important factor affecting the efficiency of sugar production and refining processes such as boiling, crystallization, separation and pumping. A rotational viscometer was used to characterize the flow behavior of date syrup solution at four different temperatures (20°C, 40°C, 60°C and 80°C) and four concentrations (17, 24, 31 and 39°Brix). The samples were subjected to a programmed shear rate increasing from 10 to 100s−1 in 2min, held constant at 100s−1 for 10min and linearly decreasing to 10 during 2min. The power law model was fitted to shear stress vs. shear rate data to obtain the consistency coefficient (m) and the flow behavior index (n). Both m and n were sensitive to changes in temperature and concentration. The apparent viscosity increases with increasing concentration of date syrup and a decrease in temperature.

Compatibility of the flocculation of Saccharomyces uvarum and fermentation optimum conditions to improve ethanol production continuously using recycle tower bioreactor

Flocculation is an attractive feature of the yeast Saccharomyces uvarum. The usefulness of its application in the fermentation process comes from the simple separation technique of the yeast cells from the fermentation products. The benefit of the flocculation of S. uvarum is that it keeps the continuous fermentation of ethanol at a certain level as it maintains the yeast inside the bioreactor and prevents it from being washed out with the ethanol. The flocculation behavior of the yeast was studied during the production of ethanol from date syrup. Furthermore, the compatibility of the optimum conditions between flocculation and ethanol fermentation was studied. Three essential parameters were studied during the continuous ethanol production: fermentation temperature, date syrup concentration, and feeding flow rate. The statistical application of central composite design was used to identify the optimum conditions that maintain the flocculation between the yeast cells and prevent it from being washed out with the product. The minimum percentage of washout yeast from the bioreactor (9.15%) was carried out under the following conditions: a temperature of 20°C, an initial date syrup sugar concentration of 6.5% (w/v), and a feeding flow rate of 294 mL h−1. In line with the optimum conditions of the ethanol production, the conditions that gave the best ethanol productivity (7.57 g L−1 h−1) with a minimum washout yeast (19.6%) was found to be a fermentation temperature of 29°C, an initial date syrup sugar concentration of 5.5% (w/v) and a feeding flow rate of 294 mL h−1. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 308–314, 2014

Dates as a substitute for added sugar in traditional foods ? A case study with idli

Scientific evidences suggest that increased intake of added sugar is one of the major causes for dental caries, glucose intolerance, diabetes mellitus, cardiovascular diseases, obesity, hypertension and behavioural complications such as hyperactivity in children. In many parts of the world, consumption of added sugar is much higher than the dietary recommendation from health organizations. Several researchers have used dried fruits to sweeten the traditional foods as the functionality of the sugar incorporated within the structure of intact fruits is different than added sugar in human health. Date fruits have also been used in several forms such as syrups, spread, sugar and flour as a sweetener in food. The objective of this study was to develop acceptable idli (traditional Indian breakfast) with chopped dates, date paste and date syrup, and determine their sensory and chemical properties. Total phenol and vitamin C contents of dates idli were significantly higher than control idli with added sugar. The sensory properties of four idli products (idli with date paste, idli with date syrup, idli with chopped dates and control idli served with white sugar) were evaluated by 40 untrained panelists. The sweetness and aroma of the idli with chopped dates got significantly higher scores than other three idli products with no difference among them. Similarly the overall acceptability score of the idli with chopped dates was higher than other idli products. Panelists from a regular eaters group gave higher scores for the overall acceptability of developed idli products than first time consumers. In all sensory attributes and consumer types, idli with dates scored higher preference or at least equal preference with control idli and white sugar combination. There are ample opportunities to educate people and create awareness about preparation and consumption of traditional foods with dates in order to reduce added sugar intake.

Lactic acid Production by a Mixed Culture of Lactic Bacteria Based on Low Value Dates Syrup and Their Metabolic Uses

The common varieties of dates represent about 30% of national production. They are generally reserved for cattle feeding and sometimes thrown into the wild. Among these varieties, palm dates very rich in carbohydrates (glucose, fructose and sucrose) and contains practically most of minerals (Ca, Fe, K, Na, etc.). The use of fermentation technology is necessary to save the genetic heritage and enhances by-product of dates in various bio products. Lactic acid is a natural organic acid. The fermentation substrates most commonly used are glucose and fructose. The lactic acid has a major importance in food and pharmaceutical industries. It is used also in drink industries, medicines etc. Algeria till today continues to import this organic acid. The objective of this study is the use of dates syrup as a substrate for the production of lactic acid, this study allowed us to have interesting results. Mixed culture of Streptococcus thermophilus and Lactobacillus bulgaricus, grown in batch fermentation. Two culture mediums were tested, the un-enriched one and the one enriched with Tween80 (1 g/l), MgSO4 (1 g/l), MnSO4 (1.5 g/l), from the results obtained by fermentation trials, the enriched medium seems best suited with a yield of lactic acid 49 g/l, where comes from its economical and commercial interest.

Effect of Date Syrup (Dips) on Growth and Survival of Probiotic Bacteria in Milk

Effect of Date Syrup (Dips) on Growth and Survival of Probiotic Bacteria in Milk

Investigation on performance of microbial fuel cells based on carbon sources and kinetic models

SUMMARY Substrate concentration has great influence on the electrical performance of a microbial fuel cell (MFC). In this study, date syrup with a high sugar content and diversified types of nutrients was used as a substrate in a dual-chambered MFC. The results obtained were compared with glucose as a conventional substrate for power generation. A pure culture of Saccharomyces cerevisiae was used as a biocatalyst in the anode chamber and potassium ferricyanide as an oxidizing agent in the cathode side. Maximum power density of 65 mW/m2 was obtained in an MFC operated with date syrup at an equivalent total carbohydrate content of 6 g/l. When the electron acceptor in the cathode side was replaced with potassium permanganate, power density was increased almost 2.5-fold and reached 234 mW/m2. The system was loaded with low to high concentrations of sugar (1–7, 10, 20 and 30 g/l). However, at high concentrations of substrates, an inverse relationship with the MFC electrical performance was observed, which was most probably due to substrate inhibition in the MFC. Substrate inhibition models were applied to investigate inhibition kinetic from an electrical point of view. Tessier, Aiba and Haldane as inhibition models were well fitted with experimental data (R2 = 0.98–0.99). The tested models revealed that the inhibitory effect for the substrate can be described in terms of model parameters. In order to evaluate the effect of the concentration of substrates on electrical performance, different inhibition concentrations were suggested by the models with respect to electrical responses achieved in the MFC. Copyright © 2012 John Wiley & Sons, Ltd.

Effect of processing conditions on phenolic compounds and antioxidant properties of date syrup

Commercial hydrolytic enzymes (pectinase and cellulase) were investigated for their influence on phenolics and antioxidant activities of date syrup. Content of total phenolics, flavonoids and carotenoids contents were determined spectrophotometrically. Polyphenols composition was examined using HPLC. Seven phenolic compounds (catechin, vanillic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid and sinapic acid) were detected in all date syrup extracts. p-Coumaric acid was the major compound of all date syrup extracts, representing 49.223–63.397%. The antioxidant activity of date syrup was evaluated by various antioxidant assays, including total antioxidant, DPPH scavenging test, FRAP, hydrogen peroxide scavenging activity and metal chelating activity.Results showed that the date syrup prepared after extraction with pectinase and cellulase mixture gave the lowest phenolic and flavonoid contents. For same variety, date syrup prepared after extraction with pectinase and cellulase mixture gave the highest carotenoids amounts. The antioxidant activity, determined by several methods, was significantly affected by the extraction method as well as date varieties. In fact, the date syrup prepared after extraction with pectinase and cellulase mixture gave the lowest antioxidant activity. A good correlation between the antioxidant activity and total phenolic content and flavonoid was observed. The discovery of our research is very important to scientists as well as to the fruit-processing industry to produce juice and syrup with high antioxidant activity.

Investigation of TiO2 nanoparticle efficiency on decolourisation of industrial date syrup

SummaryThe TiO2 nanoparticle photocatalyst was used to decolourise industrial date syrup. The effect of TiO2 concentration (1 and 4% w/v), UV power (15 and 30 w) and processing time (12 and 48 h) on date syrup characteristics was investigated using a factorial design. The colour, turbidity, sugar content, total phenolic compounds, ash content and mineral (K, Na, Ca, Mg and Fe) of date syrup were analysed. The results demonstrated that using TiO2 nanoparticle as a photocatalyst for the decolourisation of date syrup is an effective and promising method. Colour in all treatments was significantly (P &lt; 0.05) reduced between 30 and 53% in comparison with the initial date syrup (491 000 IU), and the reduction was even higher for date syrup turbidity (between 47 and 75%). The result showed that the process condition significantly affected the colour and turbidity reduction. On the basis of the result, the best treatment was TiO2 4%, 15 w and 48 h. Under this condition, date syrup colour, turbidity, ash content, sugar content reduced by 52%, 61%, 13% and 9%, respectively.

A gel-based visual immunoassay for non-instrumental detection of chloramphenicol in food samples

A gel-based non-instrumental immuno-affinity assay was developed for the rapid screening of chloramphenicol (CAP) in food samples with the limit of detection (LOD) of 1μgL−1. The immuno-affinity test column (IATC) consisted of a test layer containing anti-CAP antibody coupled gel, and a control layer with anti-HRP antibody coupled gel. Based on the direct competitive immuno-reaction and the horseradish peroxidase enzymatic reaction, the test results could be evaluated visually. Basically, blue color development represented the negative results, while the absence of color development represented the positive results. In this study, CAP spiked samples of raw milk, pasteurized milk, UHT milk, skimmed milk powder, acacia honey, date honey, fish and shrimp were tested. Little or none sample pretreatment was required for this assay. The whole procedure was completed within 10min. In conclusion, the gel-based immuno-affinity test is a simple, rapid, and promising on-site screening method for CAP residues in food samples, with no instrumental requirement.

Production of pectinase by Bacillus subtilis EFRL 01 in a date syrup medium

A newly isolated Bacillus subtilis EFRL 01 was used to produce pectinases in batch fermentations on various inexpensive media. A mineral medium based on waste date syrup (15 g/L) as the carbon source and yeast extract (7.5 g/L) as the nitrogen source proved to be the most effective. A 48 h batch fermentation in this medium with a starting pH of 8.0 produced a pectinase titer of ~2,700 U/mL at the optimal fermentation temperature of 45°C. The optimal temperature, initial pH, the carbon source and its concentration, and the nitrogen source and its concentration, were identified after evaluation of multiple nutrient sources and fermentation conditions. Keywords: Polygalactouronase, Bacillus subtilis , fermentation, pectinases, date syrup