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

Second-grade dates (with a hard texture) from three potential Tunisian cultivars (Deglet Nour, Allig and Kentichi) showed the same sugar (∼73.30–89.55 g/100 g dry matter), fibre (∼7.95–18.83 g/100 g dry matter) and total phenolics (∼280.6–681.8 mg of GAE/100 g) content as dates of high quality. Deglet Nour and Kentichi varieties were characterised by a high content of sucrose and low reducing sugar content; contrary to Allig and the majority of other date varieties tested. This work intended to add value to these raw materials by using them in jam production. The corresponding jams were characterised in terms of chemical composition, physical (texture and water retention capacities) and sensory properties. Results showed a significant effect of the date variety on the composition and physical characteristics of date jams. Indeed, Allig jam was richer in reducing sugars and was characterised by its higher firmness and water retention capacity. To test the acceptability of these new products, we compared them with quince jam (the most consumed in Tunisia). Results showed that Allig and Kentichi jams presented a higher overall acceptability. However, quince and Deglet Nour jams did not show any significant differences (P > 0.05). Results from this work revealed essential information that could promote the commercialization of dzate jam.     

Physicochemical properties of a fibrous fraction from chia (Salvia hispanica L.)

An evaluation was done of some physicochemical properties of a fiber-rich fraction (FRF) obtained by dry processing of defatted chia (Salvia hispanica) flour. The fiber-rich fraction (FRF) had 29.56 g/100 g crude fiber content and 56.46 g/100 g total dietary fiber (TDF) content, of which 53.45 g/100 g was insoluble dietary fiber (IDF) and 3.01 g/100 g was soluble dietary fiber (SDF). The FRF water-holding capacity was 15.41 g/g, its water absorption capacity 11.73 g/g, and its organic molecule absorption capacity 1.09 g/g. The FRF also had low oil-holding (2.02 g/g) and water adsorption (0.3 g/g) capacities. Emulsifying activity in this fraction was 53.26% and emulsion stability was 94.84%. Its evaluated antioxidant activity was 488.8 μmol/L Trolox equivalents/g FRF, which is higher than for many cereals and similar to drinks such as wine, tea, coffee and orange juice. The chia FRF values for the evaluated properties, particularly for water-holding, oil-holding and organic molecule absorption capacity, suggest it could be a useful ingredient in dietetic products such as baked and fried foods, among others.     

Optimization of phenolics and dietary fibre extraction from date seeds

This work was conducted to optimise extraction conditions of phenolics and dietary fibre from date seeds. The effects of solvent to sample ratio, temperature, extraction time, number of extractions and solvent type on phenolic extraction efficiency were studied. At two-stage extraction, each stage 1 h duration at 45 °C with a solvent to sample ratio of 60:1, is considered optimum. Acetone (50%), and butanone were the most efficient solvents for extraction and purification, increasing the yield and phenolic contents of seed concentrate to 18.10 and 36.26 g/100 g, respectively. The total dietary fibre of seeds (57.87 g/100 g) increased after water and acetone extractions to 83.50 and 82.17 g/100 g, respectively. Nine phenolic acids (free and liberated) were detected in seeds with p-hydroxybenzoic (9.89 mg/100 g), protocatechuic (8.84 mg/100 g), and m-coumaric (8.42 mg/100 g) acids found to be among the highest. After extraction and purification, total phenolic acid content increased significantly from 48.64 to 193.83 mg/100 g. Protocatechuic, caffeic and ferulic acids were the major phenolic acids found in the concentrates. Based on this study, we believe date seed concentrates could potentially be an inexpensive source of natural dietary fibre and antioxidants and possibly used as a functional food ingredient.     

Carotenoid composition of Algerian date varieties (Phoenix dactylifera) at different edible maturation stages

The aim of this study was to investigate the carotenoid composition and the provitamin A value of three palm date (Phoenix dactylifera) varieties (Deglet-Nour, Hamraya and Tantebouchte) from Algeria at three different ripening stages (khallal, rutab and tamr). Chromatographic analysis showed that the major carotenoid pigment present in dates is lutein followed by β-carotene, with an evident carotenoid disappearance during ripening from the khallal to the tamr stage. The different date fruits present a total carotenoid content in the range of 61.7–167, 32.6–672, and 37.3–773 μg/100 g fresh weight (FW) in Deglet-nour, Tantebouchte and Hamraya varieties, respectively. The rutab stage of Tantebouchte showed the lowest carotenoid content of 32.6 μg/100 g FW, whereas the khallal stage of Hamraya presented the highest value, 773 μg/100 g FW, followed by Tantebouchte with 672 μg/100 g FW. Provitamin A value (due exclusively to β-carotene) increased from 0.4 to 0.5 RE/100 g in Deglet-Nour fruits, but decreased from 11.7 to 1.6 RE/100 g and from 3.9 to 0.5 RE/100 g in Tantebouchte and Hamraya fruits, respectively, during ripening. The lowest value was found at the tamr stage of the Deglet-Nour variety (0.5 RE/100 g) whereas the highest provitamin A content was found at the khallal stage of the Tantebouchte variety (11.7 RE/100 g).     

Histamine contents of fermented fish products in Taiwan and isolation of histamine-forming bacteria

Twenty-seven imported fermented fish products from Southeast Asian countries and sold in the supermarkets in Taiwan, including fish sauce, fish paste and shrimp paste, were tested to determine the occurrence of histamine and histamine-forming bacteria. The levels of pH, salt content, total volatile basic nitrogen, trimethylamine, and aerobic plate count in all samples ranged from 4.8% to 6.5%, 16.2% to 45.3%, 51 to 275 mg/100 g, 5.4 to 53.9 mg/100 g and 1.0 to 4.2 log CFU/g, respectively. The average content for each of eight different biogenic amines in all samples was less than 90 ppm, except for histamine which has an average content of 394 ppm in fish sauce, 263 ppm in fish paste, and 382 ppm in shrimp paste. Most of the tested fermented fish products (92.6%) had histamine levels greater than the FDA guideline of 50 ppm, while seven of them (25.9%) contained >500 ppm of histamine. Although Bacillus coagulans and Bacillus megaterium were identified as the two histamine-producing bacteria capable of producing 13.7 and 8.1 ppm of histamine, respectively, in trypticase soy broth broth supplemented with 1.0% l-histidine, they were not determined to be the main contributors to histamine accumulation in these fermented fish products.     

The effects of added sugars and alcohols on the induction of crystallization and the stability of the freeze-dried peki (Caryocar brasiliense Camb.) fruit pulps

Peki (Caryocar brasiliense Camb.) is a Brazilian fruit with an extremely high β-carotene content, but the β-carotene is unstable under dry storage conditions. This work reports on the product development and stability of freeze-dried peki fruit pulp. Freeze-dried products were made by adding alcohols (ethanol and isopropyl alcohol; at concentrations of 0, 5 and 10 mL/100 mL of extract) and sugars (sucrose and fructose; at concentrations of 0, 5 and 10 g/100 mL of extract) to the peki fruit pulps followed by freeze-drying. Scanning electron microscopy was used to analyze the microstructure of the freeze-dried products by visualizing the crystallized forms. The product hardness and total carotenoid content following the different treatments were measured using a texture analyzer and a spectrophotometer, respectively. The stability of these foods was evaluated by their water sorption during their storage in various relative humidity environments at 25 °C. There were characteristic differences in their hygroscopic behaviors. The pretreatment with sucrose and ethanol improved the freeze-dried product and yielded a lower number of collapsed structures. Changes during the storage were observed. The pulp pretreated with sucrose was amorphous and metastable, but the drying process was accelerated by the presence of alcohol (mainly ethanol), which resulted in protected structures without any sign of collapse.     

Effect of saponins on the physical characteristics, composition and quality of akara (fried cowpea paste) made from non-decorticated cream cowpeas

Changes in the foaming capacity and viscosity of cowpea paste, affected by the addition of saponins, were investigated, as well as the subsequent effect on the texture and oil content of Akara (fried cowpea paste). Two saponins, Quillaja and Yucca, were used. Results showed a significantly greater decrease in the specific gravity after whipping (39.9-52.9%), of the paste prepared with saponins compared to that prepared without saponins (25.1-32.9%). This demonstrated the increase in foaming capacity of the paste prepared with saponins. The results also showed a higher foaming capacity for the Yucca saponin compared with the Quillaja saponin. Subsequently, there was a significant decrease in the apparent viscosity of the paste prepared with saponins and a decrease in the firmness (6.51-7.78 N) of the fried product compared to that prepared without saponins (10.89-11.58 N). These results suggest that saponins can be used to increase the foaming capacity of cowpea paste resulting in a more desirably soft, spongy-textured product. There was a significant increase in the fat content of the samples produced with saponins (25.1-42.0 g/100 g) compared to the control (18.8-19.6 g/100 g) due to the formation of more air spaces in the cowpea paste.     

Healthier oils stabilized in konjac matrix as fat replacers in n − 3 PUFA enriched frankfurters

Nutritional, sensory and technological properties of frankfurters as affected by reformulation processes designed to reduce fat content and improve fatty acid profile were investigated. Healthier oils stabilized in oil in water emulsion or in konjac matrix gel were used as fat replacers. Results showed that improved fat content by the replacement of pork backfat with konjac gel and by the addition of healthier oils stabilized by various different systems, both resulted in products with very similar characteristics. From a nutritional standpoint, reformulated frankfurters with konjac gel and/or added a healthier oil combination may claim “reduced fat content” and/or “high omega 3 fatty acid content” according to European Regulation, since they could contain less than 30% of the fat in the reference product and more than 0.6 g of ALA/100 g and more than 80 mg of the sum of EPA plus DHA per 100 g, respectively. Chill storage over 40 days generally had little effect on the technological characteristics of frankfurters.     

Effect of sodium chloride replacement and apple pulp inclusion on the physico-chemical, textural and sensory properties of low fat chicken nuggets

The effect of 40 percent sodium chloride replacement with salt substitute blend (potassium chloride, citric acid, tartaric acid and sucrose) and incorporation of apple pulp, at the levels of 8 (Treatment I), 10 (Treatment II) and 12 (Treatment III) g/100 g of formulation, on the various quality characteristics of low fat chicken nuggets was investigated. Emulsion and product pH values were significantly higher (P < 0.01) for the control when compared to treatments. Salt replacement and apple pulp addition resulted in significantly lower (P < 0.05) emulsion stability and cooking yield. Among low salt and low fat nuggets, the product with 12 g/100 g apple pulp had the highest moisture percent. Protein and ash contents were significantly lower (P < 0.01) in treatment products, whereas moisture protein ratio was higher. Incorporation of apple pulp significantly increased (P < 0.01) dietary fibre content, redness, yellowness and chroma index of the product. Textural properties of the products significantly decreased (P < 0.01) with substitution of common salt and addition of apple pulp. Sensory evaluation showed significant reduction (P < 0.01) in texture and overall acceptability scores of treatment products; however, scores were in the range of very good.     

Characterisation and optimisation of physical and oxidative stability of structured lipid-based infant formula emulsion: Effects of emulsifiers and biopolymer thickeners

Response surface methodology (RSM) was applied to investigate the effects of lecithin (0–0.4 g/100 ml), monoacylglycerol (0–0.4 g/100 ml), locust bean gum (LBG; 0–0.1 g/100 ml), and carrageenan (0–0.02 g/100 ml) on the physical and oxidative properties of structured lipid-based infant formula emulsion containing dairy proteins, lactose, vitamins, minerals and other micronutrients. Particle size, optical stability, viscosity, relative content of docosahexaenoic acid, stearidonic acid and total oxidation value were assessed during 28-day storage. ANOVA results showed that the experimental data were satisfactorily fitted to second-order polynomial models by multiple linear regression. The contour plots illustrated that lecithin and monoacylglycerol played a dominant role in controlling the emulsion stability compared to LBG and carrageenan. Lecithin content significantly affected all the responses measured, particularly lipid oxidation. Increasing monoacylglycerol concentration led to an increase in particle size and emulsion viscosity. The optimal condition to achieve the highest stability was predicted to be 0.2, 0.4, 0.045, and 0.015 g/100 ml lecithin, monoacylglycerol, LBG and carrageenan, respectively. The verification data further demonstrated the suitability of the models explored by RSM. Overall, the findings obtained in this study have important implications for the successful incorporation of structured lipid into infant formula emulsion for better infant nutrition and health.     

Carbohydrate composition and color development during drying and roasting of macadamia nuts (Macadamia integrifolia)

Research was conducted to determine whether variability in sugar content contributes to differences in kernel browning during processing of macadamia nut (Macadamia integrifolia) cultivars, Kau (HAES 344), Keaau (HAES 660), Keauhou (HAES 246), and Kakea (HAES 508). At harvest, total sugar content of fresh macadamia kernels varied from 2.9 to 5.6 g/100 g dry weight basis (db), and the average moisture content ranged from 15.6 to 23.6 g/100 g fresh weight. Cultivars differed in kernel sucrose content, but not reducing sugar content. Reducing sugars decreased during drying, and kernel centers darkened slightly. An incremental drying process limited sucrose hydrolysis, minimizing the amount of glucose and fructose available for browning reactions. Therefore, the centers of roasted kernels were not darker than dried kernels. The variability in sugar composition in fresh kernels had a minimal impact on color quality when low-temperature drying and roasting at 125 °C were used. However, when roasted kernels received from a processor were separated based on color quality, kernels with internal or external browning had higher reducing sugar concentrations (0.24-0.27 g/100 g db) than cream-colored kernels (0.03 g/100 g db). Immature kernels had higher sucrose and reducing sugar contents and more browning than mature kernels. During commercial processing, optimal conditions may not be achieved and the presence of immature nuts can contribute to kernel browning.     

Effects of replacing pork backfat with emulsified vegetable oil on fatty acid composition and quality of UK-style sausages

Rapeseed and sunflower oil were used to replace pork backfat in UK-style sausages by incorporating the oils as pre-formed emulsions. Replacing the pork backfat emulsion with rapeseed emulsion at total fat content of about 12%, reduced total saturated fatty acid (SFA) composition from 38% to 14% (4.5 to 1.8 g/100 g), increased monounsaturated fatty acid (MUFA) composition from 45% to 59% and increased polyunsaturated fatty acid (PUFA) composition from 15% to 25%. Partial replacement of pork backfat with rapeseed at a fat content of about 20% reduced SFA from 38% to 24% (7.2 to 4.8 g/100 g). There were no significant differences in eating quality and overall liking other than slight differences in the attributes ‘firmness’ and ‘particle size’. Improvement in the fatty acid composition was achieved without adversely affecting colour shelf life or lipid oxidation. The study suggests that a substantial reduction in SFA can be achieved by incorporating ‘healthy’ oils in UK-style sausages without adversely affecting eating quality or shelf life.     

全枣肉红枣粉加工技术研究

以红枣浆流变学特性的黏性指数为指标优化枣浆酶解参数,喷雾干燥法制备红枣粉,检测了主要成分的变化。得到枣浆最佳酶解条件为:去皮去核干枣与枣浆质量比为0.20,酶解温度43℃,时间4h,酶用量0.27mL/g。红枣粉喷雾干燥工艺参数为:去皮去核干枣与枣浆质量比为0.20,麦芽糊精加量与枣浆中干枣质量相等,料液进口温度为120℃,蠕动泵进料量为600mL/h。红枣总黄酮的含量随着红枣酶解、均质和喷雾干燥逐渐降低,总多酚酶解后升高而均质和喷雾干燥后下降,而总糖含量则随着酶解、均质而逐渐上升。HPLC法测定红枣中含有原儿茶酸、儿茶素、咖啡酸、表儿茶素、芦丁、肉桂酸和槲皮素,咖啡酸的含量在酶解后升高均质及喷雾干燥后降低,槲皮素的含量先升高喷雾干燥后降低,其余5种组份的含量均随着酶解、均质、喷雾干燥后降低。得到红枣原粉含量达50%的色泽微黄、枣香浓郁的产品。     

Stability of lipids and fatty acids in frozen and gamma irradiated Patagonian toothfish (Dissostichus eleginoides) from the Southwestern Atlantic

Patagonian toothfish were captured in the Southwestern Atlantic Ocean (FAO Zone N° 41). The fatty acid profile of total lipids and the triacylglycerol and phospholipid content of control and irradiated samples (1 and 5 kGy) stored at −18 °C were analyzed at 0 and 293 days post irradiation. The fatty acids are mainly monounsaturated acids (47 g/100 g total fatty acids), the most abundant one being oleic acid (18:1 n-9). This is followed in order of abundance by saturated fatty acids (26 g/100 g total fatty acids), consisting mainly of palmitic acid (16:0). Polyunsaturated fatty acids were less abundant (17 g/100 g total fatty acids) and consisted mainly of eicosapentaeonic (20:5 n-3) and docosahexaenoic (22:6 n-3) acids. Triacylglycerol content was 563.07 mg/mL oil, whereas phospholipids were 11.21 mg/mL oil. Gamma irradiation did not significantly affect the fatty acid profile or triacylglycerol and phospholipid content of P. toothfish stored for 293 days at −18 °C. The results suggest that the species exhibits a marked stability when subjected to irradiation and prolonged storage in the frozen state.     

Physical, chemical and technological characteristics of Solanum lycocarpum A. St. - HILL (Solanaceae) fruit flour and starch

Fruit of wolf (Solanum lycocarpum A. St. - HILL), found in Brazilian cerrado, has been used in the initial ripening stage as flour and/or starch in popular medicine due to its hypoglycemiant action. The aim of this work was to study the occurrence of phytochemical compounds, physical, chemical and technological characteristics of fruit of wolf flour and starch in the initial ripening stage. Flour and starch were extracted using known popularly and experimental methods (with sodium bisulfite) and chemical composition and technological characteristics were analyzed. The results were comparatively assessed by Tukey's test (p < 0.05). The recommendation for use was the extraction of flour and starch products by previously removing peels and seeds of fruit of wolf. The most relevant finding in this study is the high content of fibers in flour (23 g/100 g) and high content of resistant starch (32 g/100 g) in the fraction of starch extracted from fruit of wolf, which can explain their use as hypoglycemic agent.     

Fructooligosaccharide fortification of selected fruit juice beverages: Effect on the quality characteristics

Fortification of selected fruit juice beverages (Pineapple, Mango and Orange juice) with fructooligosaccharides (FOSs), a low calorie prebiotic has been discussed. Results indicated that sucrose which is usually used as a sweetener in fruit juice beverages can be partially substituted with FOS without significantly affecting the overall quality. The fruit juice beverages were evaluated for physicochemical and sensory changes during 6 months storage period at ambient (25 ± 2 °C) and refrigeration temperature (4 °C). The pH, total soluble solids, titratable acidity, and colour did not change significantly (P ≥ 0.05) during storage. The initial FOS content of pineapple, mango and orange juice beverages was 3.79, 3.45, and 3.62 g/100 mL. The FOS content of the fruit juice beverages stored at refrigeration temperature was 2.00-2.39 g/100 mL after 6 months of storage and 2.69-3.32, 1.65-2.08 and 0.38-0.58 g/100 mL at the second, fourth and sixth months of storage at ambient temperature respectively. The sensory analysis showed that the beverages were acceptable up to 4 and 6 months storage at ambient and refrigeration temperature respectively.     

Compositional and functional characteristics of dates,syrups, and their by-products

Three native sun-dried date varieties from Oman (namely Mabseeli, Um-sellah, and Shahal), as well as their syrups and by-products (press cake and seed) were examined for their proximate composition, dietary fibre, total phenolics, and total antioxidant activity. Carbohydrate was the predominant component in all date varieties, syrups, and their by-products, followed by moisture, along with small amounts of protein, fat, and ash. Press cakes had the highest protein content, ranging in concentration from 3.62 g/100 g in Shahal to 5.23 g/100 g in Mabseeli, whereas fat was the highest in seeds and ranged from 5.02 g/100 g in Mabseeli to 5.90 g/100 g in Um-sellah. Seeds and press cakes were found to be good sources of dietary fibre, varied between 77.75 and 80.15 g/100 g fresh weight and between 25.39 and 33.81 g/100 g fresh weight, respectively. Among dates, syrups, and their by-products, seeds had the highest contents of total phenolics (3102–4430 mg of gallic acid equivalents/100 g fresh weight) and antioxidant activity (580–929 μmol of Trolox equivalents/g fresh weight). The results obtained suggest that date by-products (particularly seeds) serve as a good source of natural antioxidants and could potentially be considered as a functional food or functional food ingredient.     

Quality of attieke (a fermented cassava product) from the three main processing zones in Côte d'Ivoire

This study aimed at assessing the quality of attiéké produced in Côte d'Ivoire. Studies were carried out on traditional processing samples taken in the three main ethnical groups and on samples produced following a mechanized process (used as reference). Sensory, physical and biochemical characteristics were measured. The results showed significant variability of quality of the attiéké from the different processing zones. The attiéké of reference showed the best sour and sweet taste, expressed by high reducing sugars content (46.25 mg/100 g) and a low lactic (59.9 mg/100 g) and acetic acids (10.03 mg/100 g) content. Attiéké produced in Adjoukrou and Alladjan zones had similar sensory, physical and biochemical characteristics. They were different to this from Ebrié producers which showed highest sour taste and acidity content. Their microbial quality became unsatisfying after only three days of storage at ambient temperature. These results constitute an important database for international specifications establishment.     

Chemical and antioxidant properties of pomegranate cultivars grown in the Mediterranean region of Turkey

Arils from six pomegranate (Punica granatum L.) cultivars obtained from various sites from the Mediterranean region of Turkey were evaluated for their chemical and antioxidant properties. These properties included total phenolics (TP), total monomeric anthocyanins (TMA), soluble solids (TSS), titratable acidity (TA), individual sugars and organic acids. Antioxidant capacities of arils were determined by both the ferric reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays. The antioxidant capacities averaged 5.60 and 7.35 mmol TE/l by the TEAC and FRAP methods. Variability among cultivars was greatest for TMA content (CV 132%); individuals ranged from 6.1 to 219 mg cy3-Gluc l⁻¹. TP means averaged 1507 mg GAE/l. Levels of FRAP, TEAC, TP, and TMA were strongly correlated (r = 0.82–0.96). The major sugars were fructose (6.4 g/100 ml) and glucose (6.8 g/100 ml), the major acids were citric (1.78 g/100 ml) and malic (0.12 g/100 ml).