Adding value to hard date (Phoenix dactylifera L.): Compositional, functional and sensory characteristics of date jam

Does hydration of 'Deglet Nour' date palm fruits improve their quality and help to reduce waste?

This work investigates the quality change of date palm fruits after hydration treatment which is commonly applied to enhance the hard textured 'Deglet Nour' fruits that are unacceptable for consumption. Date palm fruits were treated at 60-62 °C with saturated steam for 4 h in three different processing units (DPU). Mid Infrared Spectroscopy (MIR) giving a global spectral evaluation discriminates samples from the three DPUs and highlights date palm fruits of the first DPU regarding hydration treatment. Treatment led to a decrease of fruit firmness, skin lightness, and of sucrose and malic acid contents whereas citric acid and procyanidins contents and procyanidins 'degree of polymerization increased. Thermal treatment had no effect on glucose and fructose contents, on cell wall content and composition and on minor phenolic groups. Significant differences existed on dates from the three DPUs, discriminating dates presenting high firmness. Hydration treatment improve dates texture as expected while nutritional parameters were quite stable, confirming that is very promising and could be highly recommended to valorise fruit that are currently not commercialized. However, optimisation is needed for the very hard-type dates.

Potential for curdlan recovery from aerobic granular sludge wastewater treatment systems - A review

The aerobic granular sludge (AGS) biotechnology has been explored for wastewater treatment for over two decades. AGS is gaining increased interest due to its enhanced treatment performance ability and the potential for resource recovery from AGS-based wastewater treatment systems. Resource recovery from AGS is a promising approach to sustainable wastewater treatment and attaining a circular economy in the wastewater management industry. Currently, research is at an advanced stage on recovering value-added resources such as phosphorus, polyhydroxyalkanoates, alginate-like exopolysaccharides, and tryptophan from waste aerobic granules. Recently, other value-added resources, including curdlan, have been identified in the aerobic granule matrix, and this may increase the sustainability of biotechnology in the wastewater industry. This paper provides an overview of AGS resource recovery potential. In particular, the potential for enhanced curdlan biosynthesis in the granule matrix and its recovery from AGS wastewater treatment systems is outlined.

Antioxidant properties of date seeds extract (Phoenix dactylifera L.) in alloxan induced damage in rats

The study was conducted to examine the antioxidant activity and evaluate the protective effects of the date seeds powder kentichi against alloxan-induced damage in the liver, kidney, and pancreas in diabetic's rats. Group 1: control group, that did not receive any treatment, Group 2: alloxan was injected intraperitoneally (120 mg/kg body weight) for two days (Diab), Group 3: treated only by date seeds powder added in the diet (300 g/kg) for 6 weeks (DSPK), Group 4: alloxan-diabetic rats treated with date seeds powder (300 g/kg) (DSPK + Diab). Estimations of biochemical parameters in blood were determined. TBARS, SOD, CAT, and GPx activities were determined. A histopathological study was done by immersing pieces of both organs in a fixative solution followed by paraffin hematoxylin-eosin staining. In addition, the antioxidant activities of DSPK were evaluated by DPPH radical scavenging activity, reducing power, and ABTS free radical scavenging. The results revealed that date seeds significantly decreased serum levels of glucose, cholesterol, triglycerides, urea, creatinine, T-protein, ALP, D-bili and T-bili levels. In addition, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities that had been reduced in liver, kidney, and pancreas of the treated group were restored by DSPK treatments and, therefore, the lipid peroxidation level was reduced in the liver, kidney and pancreas tissue compared to the control group. Additionally, the histological structure in these organs was restored after treatment with date seeds powder.

Effects of Extraction and Evaporation Methods on Physico-Chemical, Functional, and Nutritional Properties of Syrups from Barhi Dates (Phoenix dactylifera L.)

Date fruits (Phoenix dactylifera L.) are rich in sugar and also contain a substantial amount of phenolic compounds. Therefore, date fruits can be used to produce an alternative sweetener, having lower glycemic index than sucrose. This study investigated the effects of extraction and evaporation methods on various properties of the syrups prepared from Barhi dates. Extraction of date juice with the aid of pectinase or cellulase significantly enhanced the production yield, total phenolic content, and antioxidant activities determined by Ferric Reducing Antioxidant Power and Oxygen Radical Absorbance Capacity assays. Syrups prepared without enzyme application had about 6–7 times higher apparent viscosity than those prepared from the enzyme-assisted extracted juices. Vacuum evaporation produced syrups with significantly lighter color and inferior antioxidant properties than open heating. Properties of date syrups prepared with or without enzyme-assisted extraction followed by open heat evaporation were not different. They had a glucose-to-fructose ratio close to 1:1, received good sensory acceptability scores of above 6 on a 9-point hedonic scale, contained a safe level (<40 mg/kg) of 5-hydroxymethyl-2-furfuraldehyde, and exhibited similar glass transition and melting temperatures; while a greater inhibition on α-amylase activity was observed in syrups obtained from enzyme-assisted extraction. The in vivo glycemic measurement revealed that the syrup prepared with the aid of Pectinex and open heating was classified as low glycemic index (GI = 55) and medium glycemic load (GL = 11). Thus, enzyme-assisted extraction of date juice using Pectinex could be used to produce a healthy natural sweetener from low quality date fruits.

Applications of date pits in foods to enhance their functionality and quality: A review

Summary of the abstract

Ferocactus herrerae Fruits: Nutritional Significance, Phytochemical Profiling, and Biological Potentials

The current study reports for the first time the nutritional, fruit volatiles, phytochemical, and biological characteristics of Ferocactus herrerae J. G. Ortega fruits. The nutritional analysis revealed that carbohydrate (20.6%) was the most abundant nutrient followed by dietary fibers (11.8%), lipids (0.9%), and proteins (0.8%). It was rich in vitamins, minerals, essential, and non-essential amino acids. Gas chromatography-mass spectrometry (GC-MS) analysis of the headspace-extracted volatiles showed that 3-methyl octadecane (35.72 ± 2.38%) was the major constituent detected. Spectrophotometric determination of total phenolic and flavonoid contents of the fruit methanolic extract (ME) showed high total phenolic [9.17 ± 0.87 mg/g gallic acid equivalent (GAE)] and flavonoid [4.99 ± 0.23 mg/g quercetin equivalent (QE)] contents. The ME was analyzed using high-performance liquid chromatography with ultraviolet (HPLC-UV), which allowed for both qualitative and quantitative estimation of 16 phenolic compounds. Caffeic acid was the major phenolic acid identified [45.03 ± 0.45 mg/100 g dried powdered fruits (DW)] while quercitrin (52.65 ± 0.31 mg/100 g DW), was the major flavonoid detected. In-vitro assessment of the antioxidant capacities of the ME revealed pronounced activity using three comparative methods; 2, 2-diphenyl-1-picrylhydrazyl (DPPH) (132.06 ± 2.1 μM Trolox equivalent (TE) /g), 2,2'-azino-di(3-ethylbenzthiazoline-6-sulfonic acid (ABTS), (241.1 ± 5.03 uM TE/g), and ferric reducing antioxidant power (FRAP) (258.9 ± 1.75 uM TE/g). Besides, remarkable anti-inflammatory [COX-1 (IC₅₀ = 20.2 ± 1.1 μg/mL) and COX-2 (IC₅₀ = 9.8 ± 0.64 μg/mL)] and acetylcholinesterase inhibitory (IC₅₀ = 1.01 ± 0.39 mg/mL) activities were observed. Finally, our results revealed that these fruits could be used effectively as functional foods and nutraceuticals suggesting an increase in their propagation.

Effect of Inclusion of Date Press Cake on Texture, Color, Sensory, Microstructure, and Functional Properties of Date Jam

Date press cake (DPC) is a by-product of the date syrup industry with a high content of dietary fibers, minerals, and antioxidant compounds. Accordingly, the present study aimed to evaluate the inclusion of DPC on the color parameters, texture profile, sensory evaluation, microstructure properties, total phenolics, and antioxidant capacity of date jam. The DPC was included in the preparation of date jam in an increasing level of 0, 3, 6, 9, and 12% (w/w). The results revealed that increasing DPC levels significantly increased the hardness, cohesiveness, adhesiveness, and chewiness properties of date jam. The increase in DPC inclusion levels significantly decreased the L* values and increased the a*, b*, and ΔE values of the jam. The DPC addition significantly increased the phenolics content and antioxidant capacity in a dose-dependent manner and the highest value reported in the jam contained 12% DPC by 40.02 and 11.50% compared to the control, respectively. The scanning electron microscopy results revealed that the addition of DPC up to 9% resulted in a jam surface with a denser network, homogeneous structure, and without cracks and pores, indicating improvement in the morphological properties. The sensory evaluation results showed that date jam prepared with 9% DPC had the highest overall acceptability score. This study revealed the potential use of DPC in date jam formulation up to 9% as a natural, functional, and low-cost ingredient to improve the jam’s textural properties, antioxidant capacity, and overall acceptability.

Partial substitution of sugar by honey in a pumpkin-based jam: Impact on physicochemical, microbiological quality and sensory attributes during refrigerated storage

The current study aimed to monitor the physicochemical, microbiological quality and sensory profile of pumpkin jam enriched with different proportions of honey, for an interval of 20 days during two months storage period. For that purpose, five jam samples were prepared; the first sample (A) is a control jam without addition of honey, the other four formulations B, C, D and E were prepared by replacing the granulated sugar with honey in different proportions of 5, 10, 15 and 20%, respectively. A decrease was observed in pH from 4.43 to 4.28, °Brix from 45.7 to 42.30%, except the sample C (fortified with 10% of honey) which showed Brix stability during storage; an increase in moisture content from 35.40 to 35.91%, titratable acidity from 1.163 to 1.179% was noted during evaluation. Microbiological examinations indicate that jams were microbiologically stable according to standards in force as all the count of the germs sought revealed lower loads and the total absence of pathogenic germs up to 60 days of refrigerated storage. The appreciation of jams by tasters tended to decrease towards the end of storage, where, on a hedonic scale of 5 points, the scores exhibited values between 1.3 and 3.6.

Use of natural low-methoxyl pectin from sunflower by-products for the formulation of low-sucrose strawberry jams

BACKGROUND

Due to the increasing incidence of obesity and cardiovascular diseases, consumers are demanding products with lower sugar content. In this sense, the reformulation of traditional foods with improved, safe and tasty ingredients is arousing a huge interest. Jams are conventionally produced with elevated amounts of sucrose, which increase the glycaemic index and must be avoided in certain kinds of consumers.

RESULTS

This paper describes for the first time the elaboration of strawberry jams using low-methoxyl pectins from sunflower by-products, which allowed the addition of low amounts of sucrose (10-30%). These jams were compared with best-selling commercial samples. An in-depth physicochemical, compositional, sensorial and rheological characterization was carried out. The obtained jams were safe considering a_w and pH values; samples presented enough acidity to avoid microorganism development and syneresis. The stabilizing role of sunflower pectin is noteworthy in terms of colour and other physicochemical characteristics. The organoleptic analysis showed that the taste and sweetness of laboratory samples were highly valued, although the presence of pieces of fruits was disliked some panellists. After knowing the content of added sugar used in each jam, the tasters preferred samples with 20% and 30% of sucrose over commercial samples.

CONCLUSIONS

The results show the usefulness of sunflower pectin for the elaboration of jams of low glycaemic index. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Extraction and Evaluation of Bioactive Compounds from Date (Phoenix dactylifera) Seed Using Supercritical and Subcritical CO2 Techniques

Date (Phoenix dactylifera) seed is a potential source of natural antioxidants, and the use of innovative green and low temperature antioxidant recovery techniques (using CO2 as solvent) such as supercritical fluid (SFE) and subcritical (SubCO2) extractions can improve their yields and quality in the extracts. SFE, SubCO2 and Soxhlet techniques were employed to enrich antioxidants in extracts from Sukari (SKSE), Ambara (AMSE), Majdool (MJSE) and Sagai (SGSE) date seeds. Extract yields were evaluated and modelled for SFE extract using response surface methodology. Significantly higher (p < 0.05) phenolics (143.48−274.98 mg GAE/100 g), flavonoids (78.35−141.78 mg QE/100 g), anthocyanins (0.39−1.00 mg/100 g), and carotenoid (1.42−1.91 mg BCE/100 g) contents were detected in extracts obtained using SFE and SubCO2 methods. The evaluation of in vitro antioxidant properties showed that SFE and SubCO2 seed extracts demonstrated promising antioxidant (13.42−23.83 µg AAE/mL), antiradical (228.76−109.69 µg/mL DPPH IC50), ferric reducing antioxidant power (1.43−2.10 mmol TE/100 g) and ABTS cation scavenging (375.74-717.45 µmol TE/100 g) properties that were significantly higher than Soxhlet extracts. Both SFE and SubCO2 techniques can be effectively utilized as innovative and environmentally friendly alternatives to obtain high quality antioxidant rich extracts from date seed. These extracts may have potential functional and nutraceutical applications.

The metaxenia effects of different pollen grains on secondary metabolites enzymes and sugars of 'Piarom' date palm fruit

In this research, the characteristics of pollen were studied in eight pollinating cultivars of date palm, namely, ‘Shahani’, ‘Kabkab’, ‘Zahedi’, ‘Beraem’, ‘Faryab’, ‘Sheikhali’, ‘Fard’ and ‘Jarvis’. The characteristics were compared and metaxenia effects were evaluated on secondary metabolites, enzymes and other biochemical compounds of ‘Piarom’ date fruits. The evaluations were carried out during four stages of fruit growth and development. The pollen of these eight pollinating cultivars were compared in terms of carbohydrates, proteins, starch, total phenol, flavonoids, pectin methyl esterase, and amylase enzymes. According to the results, the pollen of ‘Sheikhali’, ‘Fard’, ‘Zahedi’ and ‘Shahani’ cultivars contained more of the above compounds, compared to the other cultivars. Regarding the effects of pollen on the composition of ‘Piarom’ date fruits, ‘Fard’ and ‘Sheikhali’ pollen produced the lowest amount of soluble tannin, which resulted in a better quality of ‘Piarom’ date fruits. Pollen was also obtained from ‘Sheikhali’ and ‘Fard’ cultivars for evaluations, showing that they led to the highest amounts of glucose and fructose in the fruits. Regarding the sucrose amount, ‘Jarvis’ and ‘Shikhali’ produced the best results. Pollen of ‘Sheikhali’ and ‘Fard’ cultivars caused the lowest amount of chlorophyll at the different stages of fruit growth, indicating a better decomposition of fruit chlorophyll and, as a result, better fruit quality. Pollen of ‘Sheikhali’ and ‘Fard’ cultivars produced the highest amounts of secondary metabolites such as total phenol, carotenoids and anthocyanin at the different stages of fruit development. The pollen of ‘Fard’ and ‘Sheikhali’ cultivars produced the highest levels of polygalacturonase, cellulase and invertase enzymes at different growth stages of the ‘Piarom’ date fruit. Regarding cellulase enzyme, fruits of the ‘Zahedi’ cultivar had more cellulase than the fruits of ‘Sheikhali’. In general, the pollen of ‘Fard’ and ‘Sheikhali, in comparison with other cultivars, improved the quantity and quality of ‘Piarom’ date fruits, due to their metaxenia properties.

Date Components as Promising Plant-Based Materials to Be Incorporated into Baked Goods—A Review

Date (Phoenix dactylifera L. Arecaceae) fruits and their by-products are rich in nutrients. The health benefits of dates and their incorporation into value-added products have been widely studied. The date-processing industry faces a significant sustainability challenge as more than 10% (w/w) of the production is discarded as waste or by-products. Currently, food scientists are focusing on bakery product fortification with functional food ingredients due to the high demand for nutritious food with more convenience. Utilizing date components in value-added bakery products is a trending research area with increasing attention. Studies where the researchers tried to improve the quality of bakery goods by incorporating date components have shown positive results, with several drawbacks that need attention and further research. The objective of this review is to present a comprehensive overview of the utilization of date components in bakery products and to identify gaps in the current knowledge. This review will help focus further research in the area of valorization of date by-products and thereby contribute to the generation of novel functional bakery products that meet consumer expectations and industry standards, thus generating income for the relevant industry and considerable alleviation of the environmental burden this waste and by-products contribute to. Only a few studies have been focused on utilizing date by-products and their extracts for baked goods, while a research area still remaining under-explored is the effect of incorporation of date components on the shelf life of bakery products.

Anaerobic digestion of waste Tunisian date (Phoenix dactylifera L.): effect of biochemical composition of pulp and seeds from six varieties

Large amounts of secondary date waste (pulp and seeds) are produced and discarded in Tunisia without proper valorisation methods. To study the possibility of valorising different varieties of Tunisian date waste (pulp and seeds) via anaerobic digestion, batch biochemical methane potential (BMP) tests were carried out under mesophilic temperature. The bio-methane production curves were fitted to the model of modified Gompertz in search of the kinetic parameters. The bio-chemical characterisation of the substrates from different varieties (total and volatile solids, COD and contents in carbohydrates, proteins, lipids, polyphenols) was realised. Principal component analysis (PCA) was used to investigate the correlations between the model parameters and biochemical variables. Results show that the biochemical compositions of date pulp and seeds strongly depend on the varieties. The BMP are in the range of 0.295-0.345 and 0.267-0.327 Nm³ CH₄·kg COD^-1 for pulp and seeds respectively, resulting from the significant biochemical variance among the varieties. The BMP of date seeds was significantly correlated with their VS/TS ratio, carbohydrate and protein contents (p < 0.05). For the pulp, significant correlation was found between BMP, carbohydrate and lipid contents. PCA shows that certain varieties (like pulp and seeds of Deglet Nour and seeds of Bejou) are most suitable for being valorised by anaerobic digestion. The most suitable date varieties for this innovative approach were revealed. This research provided useful knowledge for bioconversion of waste date pulp and seeds to biomass energy.

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-F_1t-PhytoP and of 9-F_1t-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.

Correlation between physical and sensorial properties of gummy confections with different formulations during storage

Gummy confections are popular products formulated with sucrose, glucose syrups, gelling agents, acids, flavourings and colouring agents. They have various commercial types in terms of formulation, texture, taste and colour, however, there is inadequate investigation on storage behavior of these products. The aim of this study is to investigate the effects of glucose syrup:sucrose ratio (1.1 and 1.5), starch (0% and 1.5%) and gelatine concentration (3% and 6%) on texture profile, colour and sensory properties of gummy confections during storage. It was also aimed to correlate sensorial changes with physical properties measured by instrumental techniques during storage at 10 °C, 20 °C and 30 °C. The highest increase in hardness was observed for formulation with 1.1 glucose syrup:sucrose ratio, no starch and 6% gelatine. Storage temperature had no significant effect on cohesiveness. It was seen that rate of colour change increased with storage time and temperature. Formulation with glucose syrup:sucrose ratio of 1.5, no starch and 6% gelatine had the highest sensory scores. This formulation was found to be the most stable formulation in terms of hardness and gumminess, meaning that it would need a stable mastication during storage. Sensorial changes of gummy confections were found to be correlated with instrumental results of texture and colour.

Effect of heat processing on phenolics and their possible transformation in low-sugar high-moisture (LSHM) fruit products from Kainth (Pyrus pashia Buch.-ham ex D. Don) fruit

LSHM fruit products were developed using 40% Kainth fruit juice (KJ40) and 10% pomace (KP10). The percentage of fruit juice and pomace was optimized based on the sensory analysis. The effect of heat processing on the nutritional and neutraceuticals parameters was studied. The product KJ40 was rich in free phenolics, while in KP10, it was bound phenolics. Both the products had good retention of phenolics, vitamins, minerals during processing and were microbiologically safe for up to six months. UPLC-ESI-HRMS was used for the identification and quantification of major phenolic compounds. Arbutin and catechin were the most stable phenolics during processing and storage. A slight change in catechin and chlorogenic acid contents was observed, which might be transformed or degraded. Tentatively, three unknown compounds were also identified using non-targeted analysis (Marker View Software, AB Sciex). Both products might offer health benefits as rich in phenolics and dietary fiber (≥5%).

Date Fruit and Seed in Nutricosmetics

Many recent studies in the field of cosmetics have focused on organically sourced substances. Products made from organic materials are safe, high quality, cruelty-free, and more effective than those made from synthetic materials. Many organic compounds are known to be physiologically active in humans and have an extended storage capacity and long-lasting environmental effects. Agro-industrial waste has recently increased substantially, and the disposal of date palm waste, often performed in primitive ways such as burning, is harmful to the environment. Fruit processing industries generate over 10% of the total date seed waste daily, which could be converted into useful food products. Date fruit and seed are rich in sugar, vitamins, fiber, minerals, and phenolic compounds with antioxidant and anti-inflammatory properties that significantly promote human and animal health. This waste is rich in bioactive compounds and essential oils used in many kinds of food, medicine, and cosmetics. Most active cosmetic ingredients come from natural sources such as fruit, fish, and dairy, and recent research shows that date extract and seed oil help to reduce melanin, eczema, acne, and dry patches, while increasing skin moisture and elasticity. This review details the bioactive compounds and nutraceutical properties of date fruit and seed, and their use as cosmetic ingredients.

Antioxidant Capacity and Phenolic and Sugar Profiles of Date Fruits Extracts from Six Different Algerian Cultivars as Influenced by Ripening Stages and Extraction Systems

The study investigated the phenols, sugar and the antioxidant capacities of date fruit extracts obtained by organic solvents and by hydrothermal treatment from six different Algerian cultivars at two ripening stages for the first time. The analyzed cultivars exhibited potent antioxidant properties (ferric reducing antioxidant power (FRAP), 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging capacities) and different phenols regardless of the solvents and the maturity stages. About 18 phenols were identified and quantified, mainly in the hydrothermal extracts. The earlier stages were characterized by high amounts of o-coumaric acid, cinnamic acid and luteolin, with a noticeable absence of quercetin. The tamr stage presented the highest sugar content (78.15–86.85 mg/100 mg dry weight (DW)) with an abundance of glucose. Galactose was present only in some cultivars from the kimri stage (tamjouhert). Uronic acids were mostly detected at the tamr stage (4.02–8.82 mg gallic acid equivalent/100 mg dried weight). The obtained results highlight the potential of using date fruit extracts as natural antioxidants, especially at industrial scales that tend use hydrothermal extraction.

Utilizing the crop waste of date palm fruit to biosynthesize polyhydroxyalkanoate bioplastics with favorable properties

Polyhydroxyalkanoate (PHA), a family of biodegradable and renewable biopolymers that could potentially play a significant role in bioeconomy. In this study we investigated the potential of date waste (DW) biomass as feedstock to produce PHA by the halophilic archaeon Haloferax mediterranei. The concentration of essential trace elements for H. mediterranei cells during growth and PHA biopolymer accumulation was optimized. A maximum cell dry mass of (CDM) (12.8 g L^-1) and PHA concentration of (3.20 g L^-1) were achieved in DW extract media that was not supplemented with trace elements, indicating that DW is a promising source for trace elements. The cultivation was scaled-up to fed-batch bioreactor fermentations under non-sterile conditions and resulted in CDM and PHA content of 18.0 g L^-1 and 25%, respectively. The produced PHA was confirmed to be poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with high 3-hydroxyvalerate (3 HV) content of 18.0 mol%. This 3 HV molar percent was achieved without the addition of expensive precursors. The PHBV is of high molecular weight (746.0 kDa) and narrow polydispersity (PDI = 1.5), and displayed reduced melting at 148.1 °C. The X-ray diffraction (XRD) analysis showed that the PHBV has amorphous nature which increases the degradation rates and workability of the biopolymer. The isotopic ratio ¹³C/¹²C (δ ¹³C) for PHBV was found to be - 19.1‰, which indicated that H. mediterranei prefers lighter bonds to break and uses the lighter atoms for the biosynthesis of PHBV.

Development of a reduced-calorie high pressure processed sapodilla (Manilkara zapota L.) jam based on rheological, textural, and sensory properties

High pressure technology (400 MPa at 27 ± 1.5 °C for 10 min) was applied for the processing of jam, and target was the reduction (∼47%) of sugar requirement by using a fiber-rich fruit, that is, sapodilla. Different formulations of jam containing various combinations of pectin (0.5 to 5.0%), sugar (45 to 65%), and acid (0.5 to 1) were investigated for textural, rheological, and sensory properties of the pressure-processed jam. The textural parameters mainly hardness (varied 16 to 594 g force) of the jam samples were significantly (P < 0.01) affected by the formulation ingredients viz. sugar and pectin content. Also, an interaction effect (P < 0.01) of sugar and pectin was observed on the jam hardness. The rheological parameters (gel strength, K') also varied (1036 to 2852 Pa) with the change in total soluble solids (TSS) and pectin content. However, the samples having lower TSS content (e.g. 45%) and appropriate pectin content (4.0, 4.5, or 5.0%) were similar (P > 0.05) to the samples having higher TSS content (65%) and corresponding pectin level (0.5, 1.0, or 1.5%) based on the rheological properties. On the other hand, the samples with middle levels of pectin at the corresponding TSS level (45 to 65%) were highest (score of >6 on seven-point hedonic scale) and equally preferred (P > 0.05) by the sensory panelist based on overall acceptability calculated from the scores obtained for sensory attributes viz. color, aroma, sweetness, sourness, texture, and spreadability. Therefore, the jam formulation containing sapodilla pulp as a base material, TSS 45%, pectin 4.5%, and citric acid 0.5% was determined to be the preferred formulation for the production of reduced-calorie, pressure-processed jam based on its gel strength, overall acceptability, and storage stability. PRACTICAL APPLICATION: High-fiber fruit was used for the development of a reduced-calorie high pressure processed jam in this study. The inherited or externally added fiber can favor the reduction in sugar requirement of a food product particularly those processed by high pressure, leading to reduction in calories. The findings of this study can be used for the development of novel HPP products with functional properties.

Syrup from Common Date Variety (Phoenix dactylifera L.): Optimization of Sugars Extraction and their Quantification by High Performance Liquid Chromatography

Background:

In Algeria, important quantities of secondary date variety (Phoenix dactylifera L.) are generated in each campaign; their chemical composition is similar to that of commercial dates. The present work aims to valorize this common date variety (Degla-beida) which is often poorly exploited.

Methods:

In this context, we tried to prepare syrup from the secondary date variety and evaluate the effect of conventional extraction (CE) or water bath extraction (WBE) and alternative extraction (microwaves assisted extraction (MAE) and ultrasound-assisted extraction (UAE)) on its total sugar content (TSC), using response surface methodology (RSM). Then, the analysis of individual sugars was performed by high performance liquid chromatography (HPLC).

Results:

Maximum predicted TSC recoveries under the optimized conditions for MAE, UAE and CE were 233.248 ± 3.594 g/l, 202.889 ± 5.797 g/l and 233.535 ± 5.412 g/l, respectively, which were close to the experimental values: 233.796 ± 1.898 g/l; 202.037 ± 3.401 g/l and 234.380 ± 2.425 g/l. HPLC analysis revealed high similarity in the sugar composition of date juices obtained by MAE (60.11% sucrose, 16.64% glucose and 23.25% fructose) and CE (50.78% sucrose, 20.67% glucose and 28.55% fructose), although a large difference was detected for that obtained by UAE (0.00% sucrose, 46.94% glucose and 53.06% fructose).

Conclusion:

Microwave-assisted extraction was the best method for the preparation of date syrup with an optimal recovery of total sugar content. However, ultrasound-assisted extraction was the best one for the preparation of date syrup with high content of reducing sugars.

Study of Nutritional and Organoleptic Quality of Formulated Juices from Jujube (Ziziphus lotus L.) and Dates (Phoenix dactylifera L.) Fruits

The present work aims to elaborate many juice formulas (F1 to F8) from two dried fruits (jujubes: Ziziphus lotus L. and dates: Phoenix dactylifera L.). Physicochemical and biochemical characterization of the formula juices shows that juices rich in dates fruits (F1, F3, F5, and F7) are loaded, on average, in total sugars (129.5 g/l), proteins (3.02 g/l), lipids (1.08 g/l), and carotenoid (0.02 mg/l), while juices rich in jujube fruits (F2, F4, F6, and F8) are overloaded, on average, in phenolic compounds (697 mg/l), flavonoids (6.32 mg/l), condensed tannins (2.1 mg/l), hydrolysable tannins (359.5 mg/l), and viscosity (1.062 mm 10–3 s). All formulations developed have a pH that rotates between 5.12 and 5.20. Total antioxidant capacity (CAT) reveals that formulations F1, F3, F5, and F7 show a strong activity compared to the other formulas. The DPPH test shows that all formulated juices have the same antioxidant profile with IC₅₀ values lower than the template (BHT and Vit C). The FRAP test reveals that F2, F4, F6, and F8 formulas have a strong reducing power. Organoleptic evaluation by a jury shows that F4 formula is the best in terms of odor, aroma, and aftertaste agreeability.

Effect of extraction methods on the physicochemical, structural, functional, and antioxidant properties of the dietary fiber concentrates from male date palm flowers

The current study evaluates the effect of both aqueous and alkaline extraction methods on the physicochemical, structural, functional, and antioxidant properties of dietary fibers (DF) from male date palm flowers (MDPF). The DF extracted by the alkali treatment (ADF) display a higher DF content as well as lower protein and lipid content than the DF resulting from watery extraction (WDF). The scanning electron microscopy, the Fourier-transform infrared spectroscopy, and the X-ray diffraction show that the alkaline treatment contributes to a slight modification of the structural characteristics of ADF leading to better purity and functional properties. The oil holding capacity and the antioxidant activity of ADF have improved compared to the WDF, which makes this concentrate a promoting functional ingredient and a natural antioxidant. Therefore, these findings confirm the wealth of both concentrates in DF, especially ADF, as well as their potential of functional and antioxidant properties, which emphasize their suitability to be used in food applications as functional ingredients. PRACTICAL APPLICATIONS: Nowadays, studies on the extraction of DF from vegetable waste are of considerable interest in the face of the rising global demand for dietetic food. The male date palm flowers (MDPF), an agricultural waste generated during the period of pollination, are valuable natural sources of DF and antioxidants. The insoluble DF of MDPF could be essential in a balanced diet as they could fight against obesity by creating a feeling of satiety. The presence of antioxidants, which are known for preventing or slowing cell damage caused by free radicals, could contribute to the improvement of the antioxidant properties of the formulated food. The functional properties of DF concentrates from MDPF are able to solve the technical problems of agri-food industries when used as food ingredients. The use of DF from MDPF, consequently, contributes to the minimization of waste and provides value addition to the by-product considered as waste in agricultural processing.

Chemistry and microbial sources of curdlan with potential application and safety regulations as prebiotic in food and health

Curdlan - a homopolysaccharide is comprised of glucose using β-1,3-glycosidic bond and produced by different types of microorganisms as exopolysaccharide. Curdlan gel is stable during freezing and thawing processes which find several applications in food and pharmaceutical industries. It acts as a prebiotic, stabilizer and water-holding, viscosifying and texturing agent. Additionally, curdlan gel is used as a food factor to develop the new products e.g. milk fat substitute, non-fat whipped cream, retorting (freeze-drying) process of Tofu, low-fat sausage, and low-fat hamburger. However, a great variation exists among different countries regarding the regulatory aspects of curdlan as food additives, dietary components or prebiotic substances. Therefore, the present review paper aims to discuss safety issues and the establishment of common guidelines and legislation globally, focusing on the use the applications of curdlan in the food sector including the development of noodles, meat-based products, and fat-free dairy products. This review analyzes and describes in detail the potential of curdlan as a sustainable alternative additive in health and food industries, emphasizing on the chemical composition, production, properties, and potential applications.

Desert Palm Date Seeds as a Biodiesel Feedstock: Extraction, Characterization, and Engine Testing

The development of alternative fuels is increasingly important in order to maintain ongoing global economic and technological progress in the face of fossil fuel depletion and increasing environmental damage. Desert palm date seeds have clear potential as feedstock for biodiesel production given their high oil content and availability as food waste that requires no further cultivation. In this study we investigated the optimum production processes and conditions for date seed oil biodiesel, including characterizing the intermediate product and correcting its composition to meet international fuel standards. Four biodiesel blends were prepared (B5, B10, B15, and B20) and tested in a compression ignition engine at engine speeds from 1600 to 3600 rpm (200 rpm increments) and three engine loads (50%, 75%, and 100%). The highest oil yield and biodiesel conversion achieved were 10.74 wt.% and 92%, respectively. The biodiesel properties conformed well with the standards; the values for brake power, brake thermal efficiency, and brake specific fuel consumption were comparable with petrol diesel, though the latter was slightly superior. All blends produced lower levels of CO2, CO, and HC but higher levels of NOx emissions. These results demonstrate the fundamental suitability of date seeds as biodiesel feedstock, deserving of further research.

Sugar profile, volatile compounds, composition and antioxidant activity of Sukkari date palm fruit

The target of this research was to determine sugar profile, volatile compounds, minerals content and antioxidant properties of the Sukkari date flesh as methanolic and ethanolic extracts. Sukkari date showed sugar 78.32% (dry weight), while fibre, crude protein, ash and crude fat were 3.15, 3.01, 2.30 and 0.56, respectively. Glucose (51.80%), fructose (47.50%), while small amount sucrose, fucose and galacturonic acid were also detected. Potassium, calcium and magnesium were observed to be the predominant. Twenty-two components were identified; 5-Hydroxymethylfurfural was present in the highest amount (27.25%), followed by 4H-Pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl (9.45%). Total phenolic and flavonoid content of methanolic extract were 62.50 mg GAE/100 g and 3.20 mg CE/100 g, respectively, against 60.25 mg GAE/100 g and 2.90 mg CE/100 g respectively, for ethanolic extracts. Three assays including DPPH, reducing power and ABTS radical scavenging activities showed a good antioxidant activity of date palm extract. Sukkari date was observed to have good nutritional and antioxidant characteristics and can be utilize as potential nutrition.

Phytochemical profiles, and antimicrobial and antioxidant activities of greater galangal [Alpinia galanga (Linn.) Swartz.] flowers

Previous studies of galangal (Alpinia galanga) have focussed mostly on rhizomes but seldom on flowers. A comprehensive look at galangal flowers could reveal additional benefits. The chemical composition of galangal flowers was significantly (p < 0.05) different from that of galangal rhizome. Pentadecane and α-humulene were identified as major compounds of galangal flower essential oil. 1'-acetoxyeugenol acetate was identified as the highest compound in flowers and exhibited the strongest antimicrobial activity among all fractions, with MIC₅₀ values of 34 μg/ml against Staphylococcus aureus and 68 μg/ml against Listeria monocytogenes. Galangal flowers had a 3-fold higher total phenols content than had rhizomes (10.5 vs. 3.33 mg GAE/g powder). The antioxidant activities of different flower fractions varied from 2 to 4.45 mmol  trolox/g phenolics. These findings suggest that antimicrobial and antioxidant agents extracted from galangal flowers could potentially be utilized as natural food preservatives or as therapeutic agents.

Elaboração e caracterização de doce cremoso de caqui com adição de sementes da araucária

Resumo A inovação é um dos pilares para o alcance do desenvolvimento sustentável e, para a inserção de um novo produto alimentício no mercado, abordagens que englobem pesquisas em ciência e tecnologia se fazem necessárias. Visando propor uma alternativa para o uso do pinhão e o aproveitamento de frutos de clima temperado, cultivados no Estado do Paraná, foi elaborado um doce cremoso de caqui, substituindo-se parcialmente a polpa por diferentes concentrações de pinhão nas formulações (0, 5 e 10%). Foram realizadas análises de sólidos solúveis, atividade de água, pH, acidez total titulável, teor de umidade, cinzas, cor e textura, além da caracterização microbiológica dos produtos. Atendendo aos padrões de identidade e qualidade quanto às características físicas, químicas e microbiológicas, a inserção de sementes de pinhão e a consequente redução no teor de polpa promoveram, do ponto de vista tecnológico, o desenvolvimento adequado deste produto inovador. Os valores da atividade de água, a concentração de açúcares e a baixa acidez observados no produto tornaram o ambiente desfavorável ao desenvolvimento de micro-organismos, condições estas associadas às boas práticas de fabricação. A alteração na formulação padrão influenciou na análise instrumental do perfil de textura, devido à presença de amido da semente de pinhão. Os parâmetros de cor apresentaram resultados de baixa luminosidade, o que reporta a produtos pouco translúcidos, o que é característico de alimentos de alto teor de açúcares, concentrados por evaporação. No espaço de cor notou-se a expressão da cromaticidade a* e b*, que apontam para a predominância das cores amarelo e vermelho, característicos do fruto de origem. As investigações abordadas revelam a aplicabilidade tecnológica do pinhão, contribuindo para a agregação de valor através da diversificação de produtos e mostrando-se como uma alternativa para geração de recursos financeiros para pequenos produtores rurais através do extrativismo, garantindo a conservação de espécies da Floresta com Araucária.

Development of low calorie jams with increased content of natural dietary fibre made from tomato pomace

In this study, four jam formulations were developed, starting with the basic formulation (Jam 1) containing sucrose and without added pectin. Sucrose was partially (50%) replaced by stevioside in formulations of Jam 2 and 3, while in Jam 4 sucrose was completely replaced by fructose and stevioside, making this formulation suitable for diabetic patients. Jam formulations 1 and 2, prepared without added pectin, were thermally stable in the temperature range of 25-90°C, which indicate their potential use as fruit fillings. Jam formulations 3 and 4 were assessed by the sensory panel as more spreadable since tomato pomace particles are incorporated in pectin network which acts as a lubricant. Jam formulations were characterized by a lower total carbohydrate content (17.23-43.81%) and lower energy value (87.1-193.7kcal/100g) when compared to commercial products. Tomato pomace jams contained 15-20 times more dietary fibre than commercial apricot jam.