Antioxidant activity, nutritional, and phenolic composition of sweet potato leaves as affected by harvesting period

In the present study, the nutritional and phenolic composition as well as the antioxidant activity of sweet potato leaves (SPL) harvested in 3 different periods were determined and compared. Furthermore, gray relational analysis was used to compare the comprehensive nutritional value. Results showed SPL HP1 had the highest protein value (30.8 ± 0.4 g/100 g dw), while SPL HP3 had the highest content of vitamin C (104.6 ± 4.9 mg/100 g dw), vitamin E (5.8 ± 0.4 mg/100 g dw), total polyphenol content (9.1 ± 0.3 g/100 g dw), antioxidant activity (DPPH: 7.4 ± 0.1 g VcE/100 g dw; ABTS: 10.6 ± 0.7 g VcE/100 g dw; FRAP: 0.617 ± 0.005 µmol TroloxE/100 g dw), and comprehensive nutritional value (weighted gray relational grade 0.8336). The individual phenolic composition showed the presence of six caffeoylquinic acids, caffeic acid, and two flavonoids (quercetin and isoquercetin), which were significantly different among different harvest periods. In conclusion, HP3 was an optimal period for harvesting SPLFil: Suárez, Santiago. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Chinese Academy of Agricultural Sciences; ChinaFil: Mu, Taihua. Chinese Academy of Agricultural Sciences; ChinaFil: Sun, Hongnan. Chinese Academy of Agricultural Sciences; ChinaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

Study on Dynamic Response Measurement of the Submarine Pipeline by Full-Term FBG Sensors

The field of structural health monitoring is concerned with accurately and reliably assessing the integrity of a given structure to reduce ownership costs, increase operational lifetime, and improve safety. In structural health monitoring systems, fiber Bragg grating (FBG) is a promising measurement technology for its superior ability of explosion proof, immunity to electromagnetic interference, and high accuracy. This paper is a study on the dynamic characteristics of fiber Bragg grating (FBG) sensors applied to a submarine pipeline, as well as an experimental investigation on a laboratory model of the pipeline. The dynamic response of a submarine pipeline under seismic excitation is a coupled vibration of liquid and solid interaction. FBG sensors and strain gauges are used to monitor the dynamic response of a submarine pipeline model under a variety of dynamic loading conditions and the maximum working frequency of an FBG strain sensor is calculated according to its dynamic strain responses. Based on the theoretical and experimental results, it can be concluded that FBG sensor is superior to strain gauge and satisfies the demand of dynamic strain measurement

Evaluation of different hydrocolloids to improve dough rheological properties and bread quality of potato-wheat flour

peer reviewedThe aim of study was to investigate the effect of hydroxylpropylmethylcellulose (HPMC), arabic gum (AG), konjac glucomannan (KG) and apple pectin (AP) at 2% (w/w, potato-wheat flour basis) on the potato-wheat dough (the mass ratio was 1:1) rheological, fermentation properties and its bread quality. The tan δ of potato-wheat dough was significantly increased by adding HPMC compared to those of without adding hydrocolloids (from 0.337 to 0.425), which was close to wheat dough (0.531). Moreover, the dough height during fermentation process was significantly improved by adding hydrocolloids, with the order of HPMC (23.1mm) > AP (19.3mm) > AG (18.6mm) > KG (13.6mm). In addition, the potato-wheat protein bands of potato-wheat dough turned pale by adding hydrocolloids, suggesting higher molecular weight aggregation formed between proteins-hydrocolloids or proteins-proteins after fermentation process. Furthermore, HPMC significantly increased specific volume (from 1.45 to 2.22 ml/g), and hydrocolloids restrained the starch retrogradation of potato-wheat breads.Research Project: Research and Demonstration of Key Technology System of Potato Staple Food (201503001-2

Bacterial characterization of fermented sweet potato leaves by high-throughput sequencing and their impact on the nutritional and bioactive composition

Bacterial, nutritional, and bioactive compositions of fermented sweet potato leaves (SPL) were investigated. Three samples were utilized: control (C), natural fermentation (NF), and probiotic fermentation (PF). Bacterial composition was assessed by high-throughput sequencing. Lactobacillus plantarum and Enterococcus durans were identified in NF. Lactobacillus plantarum was also found in PF, showing a relative abundance of 90.2%. Polyphenol composition determined by HPLC changed considerably during NF decreasing its concentration to a value of 6.69 mg/g dw compared to the value found in C (42.77 mg/g dw). PF maintained the polyphenol concentration (38.64 mg/g dw) but some interconversion between polyphenols seems to occur. ABTS radical scavenging capacity value was similar in C and PF, demonstrating no changes in antioxidant activity. During PF antioxidant activity was maintained, and angiotensin-converting enzyme inhibitory activity was even improved. Fermentation was a good process for SPL. According to the parameters assessed, PF was better than NF. Novelty impact statement: The effect of natural and probiotic fermentations on the bacterial composition, nutritional, and bioactive composition of sweet potato leaves was compared. Results showed that fermentation was a good process for sweet potato leaves. According to the parameters assessed, probiotic fermentation was better than natural fermentation.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Antioxidant activity, nutritional, and phenolic composition of sweet potato leaves as affected by harvesting period

In the present study, the nutritional and phenolic composition as well as the antioxidant activity of sweet potato leaves (SPL) harvested in 3 different periods were determined and compared. Furthermore, gray relational analysis was used to compare the comprehensive nutritional value. Results showed SPL HP1 had the highest protein value (30.8 ± 0.4 g/100 g dw), while SPL HP3 had the highest content of vitamin C (104.6 ± 4.9 mg/100 g dw), vitamin E (5.8 ± 0.4 mg/100 g dw), total polyphenol content (9.1 ± 0.3 g/100 g dw), antioxidant activity (DPPH: 7.4 ± 0.1 g VcE/100 g dw; ABTS: 10.6 ± 0.7 g VcE/100 g dw; FRAP: 0.617 ± 0.005 μmol TroloxE/100 g dw), and comprehensive nutritional value (weighted gray relational grade 0.8336). The individual phenolic composition showed the presence of six caffeoylquinic acids, caffeic acid, and two flavonoids (quercetin and isoquercetin), which were significantly different among different harvest periods. In conclusion, HP3 was an optimal period for harvesting SPL.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Preparation of cellulose nanofibers from potato residues by ultrasonication combined with high-pressure homogenization

peer reviewedIn this study, the preparation parameters of cellulose nanofibers from potato residues (PCNFs) by ultrasonication combined with high-pressure homogenization were optimized based on yield, zeta-potential and morphology. The optimal parameters were as follows: ultrasonic power of 125 W for 15 min and homogenization pressure of 40 MPa four times. The yield, zeta potential and diameter range of the obtained PCNFs were 19.81%, –15.60 mV and 20–60 nm, respectively. Fourier transform infrared spectroscopy, X-ray diffraction and nuclear magnetic resonance spectroscopy results showed that part of the crystalline region of cellulose was destroyed, resulting in a decrease in crystallinity index from 53.01% to 35.44%. The maximum thermal degradation temperature increased from 283 °C to 337 °C. PCNFs suspensions were non-Newtonian fluids and exhibited rigid colloidal particle properties. In conclusion, this study provided alternative uses for potato residues generated from starch processing and showed great potential for various industrial applications of PCNFs

Evaluation of different hydrocolloids to improve dough rheological properties and bread quality of potato-wheat flour

The aim of study was to investigate the effect of hydroxylpropylmethylcellulose (HPMC), arabic gum (AG), konjac glucomannan (KG) and apple pectin (AP) at 2% (w/w, potato–wheat flour basis) on the potato–wheat dough (the mass ratio was 1:1) rheological, fermentation and bread making properties. The tan d of potato–wheat dough was significantly increased upon addition of adding HPMC which was close to wheat dough (0.531). Moreover, dough height during fermentation process was significantly improved on addition of hydrocolloids, with the order of HPMC (23.1 mm)[AP (19.3 mm)[AG (18.6 mm)[ KG (13.6 mm). Protein bands of potato–wheat dough were pale in the presence of hydrocolloids, suggesting the formation of higher molecular weight aggregates formed between proteins–hydrocolloids or proteins–proteins after fermentation process. Furthermore, HPMC significantly increased specific volume (from 1.45 to 2.22 ml/g), and hydrocolloids restricted the retrogradation of starch in potato–wheat breads.Centro de Investigación y Desarrollo en Criotecnología de AlimentosFacultad de Ciencias Exacta

Study on Dynamic Response Measurement of the Submarine Pipeline by Full-Term FBG Sensors

The field of structural health monitoring is concerned with accurately and reliably assessing the integrity of a given structure to reduce ownership costs, increase operational lifetime, and improve safety. In structural health monitoring systems, fiber Bragg grating (FBG) is a promising measurement technology for its superior ability of explosion proof, immunity to electromagnetic interference, and high accuracy. This paper is a study on the dynamic characteristics of fiber Bragg grating (FBG) sensors applied to a submarine pipeline, as well as an experimental investigation on a laboratory model of the pipeline. The dynamic response of a submarine pipeline under seismic excitation is a coupled vibration of liquid and solid interaction. FBG sensors and strain gauges are used to monitor the dynamic response of a submarine pipeline model under a variety of dynamic loading conditions and the maximum working frequency of an FBG strain sensor is calculated according to its dynamic strain responses. Based on the theoretical and experimental results, it can be concluded that FBG sensor is superior to strain gauge and satisfies the demand of dynamic strain measurement

Influence of different hydrocolloids on dough thermo-mechanical properties and in vitro starch digestibility of gluten-free steamed bread based on potato flour

The effects of hydrocolloids (Hydroxypropylmethylcellulose (HPMC), Carboxymethylcellulose (CMC), Xanthan gum (XG), and Apple pectin (AP)) at different concentrations on dough thermo-mechanical properties and in vitro starch digestibility of gluten-free potato steamed bread were investigated. Results showed that hydrocolloids addition significantly increased the gelatinization temperature (from 52.0 to 64.2 °C) and water absorption (from 56.22 to 66.50 %) of potato dough. Moreover, hydrocolloids may be interacted with protein and starch, the density of potato protein bands was decreased by hydrocolloids addition, the reason might be that higher molecular weight complexes might be formed between proteins-hydrocolloids or proteins-proteins, thus change the protein solubility. Furthermore, steamed breads with hydrocolloids presented higher specific volume and lower hardness, and the rapidly digestible starch and estimated glycemic index were significantly decreased from 45.51 to 20.64, from 69.54 to 55.17, respectively. In conclusion, HPMC and XG could be used as improvers in the gluten-free potato steamed bread