Date Palm By-products Research Articles

Natural Antioxidant Extracts as Anti-browning Agents from Algerian Date Palm Fruit

Abstract: Enzymatic browning is a negative change that affects fruits and vegetables. This makes them unfit for consumption or reduces their shelf life and quality. This reaction alters the appearance, texture, fragrance, taste, and nutritional value of the food. In order for these products to be widely accepted by consumers, it is necessary to use natural compounds with anti-browning properties. Objective: The main objective of this study was to select effective extracts for the anti-browning (antipolyphenol oxidase and anti-peroxidase), and antioxidant activities of by-products of Phoenix dactylifera L., Ghars variety, from Algeria. Methods: Hydro-methanolic extracts from the pedicel, perianth, and leaves of date palm were examined to evaluate the phenol and total flavonoid contents. Using spectrophotometric techniques, the antioxidant activities were assessed using 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH●), 2, 2’-azino-bis-(3- ethylbenzthiazoline-6-sulfonic acid) radical (ABTS●+) and Ferric Reducing Antioxidant Power (FRAP) assay, examined the enzyme inhibitory activity against polyphenol oxidase and peroxidase of Phoenix dactylifera L. extract. Results: The range of total phenolic and flavonoid contents was 12.29 to 48.98 mg gallic acid equivalent/ g dry matter and 2.83 to 15.07 mg rutin equivalent/g dry matter, respectively. The pedicel extracts showed significant antioxidant activity in the DPPH and FRAP tests (IC50 = 0.0057 ± 0.0010 mg/ml and FEAC = 1.1961 ± 0.0647) compared to other extracts. However, in the ABTS assay, the leaf extract exhibited an interesting potency (IC50 = 0.0020 ± 0.0001mg/ml). The study on the anti-browning activity of date palm by-product extracts showed that it inhibited the activity of peroxidase enzyme from date palm fruit. Conclusion: This work is the first time the potential of an extract from date palm by-products to enzymatically reduce the browning of date palms is presented. According to the results obtained, the different organs studied from the Ghars date palm, are a powerful natural antioxidant and may include natural compounds that retard browning by enzymes.

Effect of olive and date palm by-products on rumen methanogenic community in Barki sheep.

Rumen methanogens prevent the accumulation of fermentation gases in the rumen and generate methane that increases global warming and represents a loss in animals' gross energy. Non-traditional feed resources such as the by-products of date palm (Phoenix dactylifera) and olive (Olea europaea) trees have received attention to be used in animal feeding. This study evaluated the impact of non-traditional feed resources including olive cake (OC), discarded dates (DD), and date palm frond (DPF) in sheep diet on rumen fermentation, diversity and relative abundance of rumen methanogens. Nine adult rams were assigned to three equal groups and fed three diets: traditional concentrates mixture (S1); non-traditional concentrate mixture (S2) based on DD and OC; and (S3) composed of the same S2 concentrate supplemented with DPF as a roughage part. The results showed that rumen pH was higher with S3 diet than the other two diets. However, the S1 diet showed the highest values of total volatile fatty acids (TVFA) and rumen ammonia. In addition, the proportions of acetic and butyric acids were increased, whereas propionic acid declined in S2 and S3 compared to the S1 diet. Rumen methanogens were dominated by Methanobrevibacter that showed a numeric decline by including DD, OC, and DPF in the animal diets. Principal component analysis (PCA) based on rumen fermentation parameters and relative abundances of methanogens genera showed three distinct clusters. Also, positive and negative correlations were revealed between methanogens genera and rumen metabolites. This study expands the knowledge regarding the effect of agricultural byproducts on rumen fermentation and the methanogenic community.

Phytoprostanes from Date Palm Fruit and Byproducts: Five Different Varieties Grown in Two Different Locations As Potential sources.

Date palm fruit has been considered for centuries as an ancient nutritional constituent in the human diet. Recently, global trade in dates increased at an average that, simultaneously, will be accompanied by an increase in date palm byproducts. Supported by date phytochemicals and their health benefits, the aim of this work is to evaluate for the first time the presence of special metabolites of plant called phytoprostanes (PhytoPs) in five different varieties of the Phoenix dactylifera L. pulps and pits using a microLC-ESI-QTrap-MS/MS methodology. Results obtained showed the interest of using these matrices as potential sources of several PhytoPs (ent-16-B1-PhytoP; ent-9-L1-PhytoP; and epimers of ent-16-F1t-PhytoP and of 9-F1t-PhytoP). The variation in concentration between different varieties and different DPF parts was also evaluated. Results obtained will help to unravel the biological activities associated with DPF consumption that could be related to these bioactive metabolites.

Grafting of Dissolved Pulp from Date Palm Byproducts for Use in Industrial Water Purification

Grafting of Dissolved Pulp from Date Palm Byproducts for Use in Industrial Water Purification

Evaluation of Phoenix dactylifera Edible Parts and Byproducts as Sources of Phytoprostanes and Phytofurans.

Even though traditionally date-fruit has been featured by a marginal use, mainly restricted to its dietary intake, in recent years, it has raised the range of applications for this agro-food production. These new uses have entailed an enlarged production of date fruits and, simultaneously, of date palm byproducts. Encouraged by the traditional medicinal uses of dates, according to their phytochemical composition, the present work was focused on the evaluation of a new family of secondary metabolites, the plant oxylipins phytoprostanes (PhytoPs) and phytofurans (PhytoFs), in six separate matrixes of the date palm edible parts and byproducts, applying an UHPLC-ESI-QqQ-MS/MS-based methodology. The evaluation for the first time of date palm edible parts and byproducts as a dietary source of PhytoPs and PhytoFs provides evidence on the value of six different parts (pulp, skin, pits, leaves, clusters, and pollen) regarding their content in these plant oxylipins evidenced by the presence of the PhytoPs, 9-F1t-PhytoP (201.3-7223.1 ng/100 g dw) and 9-epi-9-F1t-PhytoP (209.7-7297.4 ng/100 g dw), and the PhytoFs ent-16(RS)-9-epi-ST-Δ14-10-PhytoF (4.6-191.0 ng/100g dw), and ent-16(RS)-13-epi-ST-Δ14-9-PhytoF as the most abundant compounds. Regarding the diverse matrixes assessed, pollen, clusters, and leaves for PhytoPs and skins and pollen for PhytoFs were identified as the most interesting sources of these compounds. In this concern, the information obtained upon the detailed characterization performed in the present work will allow unravelling the biological interest of PhytoPs and PhytoFs and the extent to which these compounds could exert valuable biological activities upon in vitro (mechanistic) and in vivo studies, allocating the effort-focus on the chemical species of PhytoPs and PhytoFs responsible for such traits.

Evaluation of compost quality and bioprotection potential against Fusarium wilt of date palm

The Fusarium wilt of date palm caused by Fusarium oxysporum f.sp. albedinis (Foa) is the most damaging disease in Morocco. It has destroyed more than 12 million trees in the country. Until now, there is no efficient approach to manage this disease. However, biocontrol of soil-borne phytopathogens with compost is currently an established horticultural approach. This study aimed to evaluate the effect of compost extracts in the biocontrol of Foa and their mechanism of action and to investigate parameters involved in compost maturity. Maturity (phytotoxicity test), sanitary quality (pathogen indicators) and in vitro suppressive effect of four composts were investigated. Date palm by-products compost produced with forced aeration composting system is not phytotoxic presenting a germination index of 83.78%. In contrast, two commercial composts were phytotoxic. The maturity was negatively correlated with salinity, C/N ratio and total soluble phenols. Concentrations of pathogen indicators were below suggested limits in all composts. The biocontrol test showed that the date palm wastes compost was more effective; from the sixth day of incubation, the unsterilized extract of this compost at 10% showed the highest antagonistic effect against the pathogen with an inhibition rate of 100%. The inhibition rate using microfiltrated extract didn’t exceed 30%. All autoclaved extracts lost their antagonistic effect against the indicator fungus. Thus, the suppressive effect is mainly due to the indigenous microorganisms. Findings indicate the relevance of maturity in the evaluation of compost quality and the efficiency of date palm wastes compost in the suppression of Foa.

Influence of adding fibrolytic enzymes on the ruminal fermentation of date palm by-products.

This study was conducted in order to assess the influence of four doses (0, 0.5, 1, and 2 mg (g dry matter) of commercial fibrolytic enzymes (MAXFIBER-I, SHAUMANN GmbH, Wahlstedt, Germany) on in vitro fermentation of date palm (Phoenix dactylifera) by-products: date kernels, wasted dates, floral stems, and palm fronds. Rumen contents were obtained from two non-lactating Holstein cows. Enzyme supplementation to by-products was carried out 12 h prior to incubation.Compared to the control, the enzymatic supplementation quadratically increased the extent but not the gas production rate of date kernel fermentation. Indeed, the potential gas production increased notably by 14.8 % with the lowest enzymes dose following recorded gas production after 48, 72, and 96 h of incubation. The estimated organic-matter digestibility, metabolisable energy, and total volatile fatty acids in the incubation fluid tended to be increased with the lowest dose by 7.8 %, 8.4 %, and 13.9 % respectively. For the wasted dates, this feed additive tended to linearly increase the gas production rate of fermentation with the highest dose. On the other hand, this supplementation had no effect on the ruminal fermentation of the floral stems and palm fronds. The exogenous fibrolytic enzymes were more effective on fibrous but not on lignified date palm by-products.

In vitro assessment of nutritive value of date palm by-products as feed for ruminants

Date-palm leaves, pedicels, date-pits and waste dates are the main date-palm by-products (DPBP), classically used as a complementary feeding source for livestock by oasis farmers. This work aims to assess in vitro the nutritive value of these DPBP, including waste dates from three varieties (Bouarus, Harchaya and Kentichi), and using vetch-oat hay as a reference feed material. Palm leaves showed the highest NDF, ADF, lignin and crude protein contents (609, 435, 84, 64 g kg-1 DM, respectively). After 144 hours of incubation, the highest cumulative gas production was observed for Kentichi dates (330 mL g-1DM) and the lowest for date-pits (69 mL g-1DM). Regardless of the variety, waste dates showed the highest DM effective degradability (ED; assuming a passage rate of 0.03 h-1) and organic matter digestibility (OMD), whereas date-pits seemed to be a poorly degradable material, with an ED coefficient of 0.09 g g-1 DM. The lowest total VFA production from ruminal fermentation was with date-pits and the highest with waste dates of the Bouarus variety. These results suggest that waste dates, albeit their low protein content, should be considered highly digestible with energy concentrations as high as that of vetch-oat hay. Palm leaves and pedicels can be considered as highly fibrous emergency roughages for low-producing animals. Protein supplementation is required when DPBP are included in the diet of ruminants.

Date palm by-products as a new ingredient for the meat industry: Application to pork liver pâté

Date palm is an interesting source of bioactive compounds that could be used as ingredient in meat products; thus a campagne type pork liver pâté was elaborated using fresh date by-products (0, 5, 10 and 15%). Physicochemical properties, pigment and lipid oxidation, residual nitrite level, texture and sensory analysis during 4days after the elaboration process were evaluated. Date paste mostly incorporated moisture, fibre and phenolic compounds. Physicochemical parameters, myoglobin content and heme iron stability were not severely affected. Addition of 10% of date was enough to avoid lipid oxidation through all storage times. Colour was the most affected parameter; however, in terms of overall acceptability, panellists preferred samples with added date.

Determination of nutritive value of date palm by-products using in vitro and in situ measurements

In this research, the nutritive values of three date palm (Phoenix dactylifera) by-products (DPB) called Lerd, Pit and Pulp in South-east of Iran were evaluated. The chemical compositions of all DPB samples were evaluated by laboratory analysis. An in vitro digestibility study was done to determine digestibility coefficients of dry matter (DMD), organic matter (OMD), and also digestible organic matter in dry matter (DOMD) to estimate the metabolizable energy (ME) content of DPB samples. In addition, dry matter (DM) and crude protein (CP) disappearance of samples were determined by an in situ method at 0, 3, 6, 12, 24, 48 and 72h and their kinetics were described using the equation p=a+b(1−e−ct). The nutritive value index (NIV) of DPB samples was calculated using the equation: NIV=a+0.4b+200c. The mean values of the DM, OM, CP, ADF and NDF were 948.8, 909.7, 80.04, 590.0 and 800.0g/kg DM for Lerd; 960.4, 933.9, 61.6, 529.7 and 640.0g/kg DM for Pit; 964.7, 929.4, 78.2, 494.3 and 625.0g/kg DM for Pulp respectively. In this study the average DMD, OMD, DOMD and metabolizable energy of DPB differed significantly (P<0.05) was higher for Pulp in comparison to Lerd and Pit. The effective DM degradability (EDMD) and effective CP degradability (ECPD) of Lerd, Pit and Pulp ranged from 19.29 to 32.83 and from 33.67 to 46.51% respectively. The average NIV of DM and CP for Pulp (59.25 and 76.47%) was higher than Pit (55.40 and 66.27%) and Lerd (34.46 and 56.82% respectively). Our results showed that DPB samples in particular Pulp can be used as proper source of feed for small ruminants to overcome the shortage of animal feedstuffs.

Measurement of Gaseous and Particulate Pollutants during Combustion of Date Palm Wastes for Energy Recovery

Being an important date-producing country, Tunisia generates high quantities of dry date palm residues which are currently not efficiently used, and instead accumulate every year in oasis lands. These by-products could present real advantages for Tunisia for energy production in both economic and environmental terms. Heating installations using biomass generate primary pollutants, such as CO, VOC and Particle Matter (PM), these latter having the most important adverse impact on environment. Measurements of these pollutants are needed, because international certification organizations require drastic limits on CO and PM emissions from biomass combustion processes. In this study, date palm leaflets (DPL), date palm rachis (DPR), date palm trunks (DPT) and date stones (DS) were combusted in a laboratory scale mobile furnace. The aim of this work was to find an appropriate of these materials for energy recovery, with low emission factors of gaseous and PM in the exhaust. Combustion tests were performed at two temperatures (500°C and 800°C) and input air flow rates (25 and 50 NL/h). With the lowest content of chlorine and the highest bulk and energetic densities, DS is the most convenient date palm residue for energy recovery. Combustion of DPL, DPR and DPT needs to be performed at high temperature to obtain a complete carbon balance, and this is not required for the combustion of DS, which has a value of 88% for the carbon balance at 500°C. Particles emitted during combustion are mainly constituted of fine and ultrafine particles. For all samples, 99% are particles with diameters below 1 μm. Combustion of DS produces the lowest content of PM0.1, leads to the lowest emissions factors of aerosols, and generates fewer tars than the other date palm by-products. An increase in the input air flow rate, and therefore decrease in the residence time during combustion of DS, generates a larger amount of aerosols.

THE EFFECTS OF FEEDING DATE PALM BYPRODUCTS ON MEAT QUALITY CHARACTERISTICS OF SHEEP

THE EFFECTS OF FEEDING DATE PALM BYPRODUCTS ON MEAT QUALITY CHARACTERISTICS OF SHEEP

Suppressive Effect of Mature Compost of Date Palm By-Products on Fusarium oxysporum f. sp. albedinis

Suppressive Effect of Mature Compost of Date Palm By-Products on Fusarium oxysporum f. sp. albedinis

Effects of feeding ensiled date palm fronds and a by-product concentrate on performance and meat quality of Omani sheep

A study was carried out to investigate the potential use of date palm by-products for feeding Omani local sheep. Thirty-two Omani sheep were fed for 120 days one of four ration combinations of two roughages and two concentrates. The roughages were urea treated palm frond (UTPF) and Rhodes grass hay (RGH). The concentrates were a pelleted commercial cubes (CC) and a concentrate made from local by-products (BC). Experimental measurements included daily feed intakes, bi-weekly body weights, hematological values, apparent digestibility, and carcass and meat quality characteristics. The BC was formulated from 250 ground date fronds, 250 wheat bran, 200 ground Prosopis juliflora pods, 150 barley grain and 120 g/kg dried sardines plus vitamin and mineral additives. The UTPF silage was prepared by ensiling shredded palm fronds in a 30 g/l urea solution for 5 weeks. On dry matter (DM) basis, the BC and CC concentrates contained 179 and 180 g/kg crude protein (CP); 241 and 56 g/kg acid detergent fiber (ADF); 379 and 182 g/kg neutral detergent fiber (NDF); 118 and 73 g/kg ash; 17.9 and 18.3 kJ/g DM gross energy (GE), respectively. The UTPF and RGH contained 85 and 100 g/kg CP; 580 and 370 g/kg ADF; 740 and 614 g/kg NDF; 120 and 95 g/kg ash; 19.2 and 17.3 kJ/g DM GE, respectively. Experimental animals fed the date palm by-products were in good health throughout the trial. In absolute terms, sheep fed the UTPF had lower feed intakes than those fed the RGH but feed intake/body weight (BW) was similar across diet groups (30 g/kg). By-products fed sheep gained less (P<0.05) weight than those fed RGH and CC. The average daily gain was 80, 56, 32 and 10 g/d for the CC + RGH, BC + RGH, CC + UTPF and BC + UTPF, respectively. Feed conversion (kg feed/kg BW gain) was lower for UTPF and BC feeds. Apparent digestibility coefficients for DM, CP, ADF, NDF, ash and DE were lower for UTPF and BC based diets. Feeding UTPF and BC reduced carcass weight, dressing, fat content and carcass measurements. However, feeding CC with UTPF improved sheep performance compared to BC + UTPF. There were no effects of feeding UTPF or BC on meat quality. This experiment indicated that date palm by-products might be used for feeding Omani sheep for maintenance or during times of nutritional shortage frequently experienced in the arid tropics.