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In this study, total polyphenol, flavonoid and anthocyanin content (TPC, TFC and TAC), antioxidant activity (AA) and individual phenolic composition of potato peel and flesh from four potato varieties were investigated. On average, TPC, TFC and TAC in the peel were 1.59 times, 2.91 times and 1.46 times higher than in the flesh, respectively. As well, the AA measured by FRAP, DPPH and ABTS was 1.64 times, 2.19 times and 1.66 times higher than in the flesh, respectively. A total of thirteen individual phenolic compounds (gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid, myricetrin, kaempferol, delphinidin, petunidin, pelargonidin, peonidin, malvidin) and ascorbic acid were identified by HPLC. Phenolic acid (chlorogenic acid) and anthocyanidins (petunidin and peonidin) were predominant in both potato peels and flesh. In addition, a very high positive correlation was found between TPC, TFC and AA, suggesting that AA could be attributed to high polyphenol content. Potato peel could be used as an important source material in the production of functional food for consumers and food industry.

Effects of boiling, steaming, microwaving, roasting and frying on proximate composition, carotenoids and antioxidant activities of orange-fleshed sweet potato (OFSP) were investigated. Retentions of 66.30–82.19% of β-carotene contents were observed after boiling (15–35 min), steaming (15, 35 and 45 min) and microwaving (15 min). High retentions of (9Z)-β-carotene were noted after all cooking processes, being 515.40% after steaming at 45 min. α-carotene was highly retained after boiling at 15–35 min (103.77–106.74%). A high retention of 91.37% in total polyphenol contents was noted after steaming (35 min), whereas 98.98–102.36% of vitamin C was retained after steaming (15–45 min) and microwaving (15 min). All cooking processes improved antioxidant activities of OFSP, and the correlation analysis between carotenoid contents and antioxidant activity suggested that antioxidant activity could be attributed to the higher contents of (9Z)-β-carotene. It was suggested that boiling and steaming are preferable to maintain carotenoids and antioxidant activities of OFSP.

Milk proteins and polyphenols are increasingly being studied as functional ingredients due to the epidemiologically-proved health benefits. In this study, composite β-lactoglobulin (β-lg) or β-lactoglobulin nanoparticles (β-lgNPs)-3,5-di-O-caffeoylquinic acid (3,5diCQA) with superior physicochemical and antioxidant activity (AA) were produced using β-lg and 3,5-di-O-caffeoylquinic acid. The main interactions between β-lg or β-lgNPs with 3,5diCQA were hydrogen bonding and hydrophobic effects. The 3,5diCQA caused a decrease in α-helix and β-sheet structure with a corresponding increase in unordered structure. Compared to β-lg alone, composite β-lg or β-lgNPs-3,5diCQA slightly decreased the particle size but increased their negative surface potentials especially for β-lg or β-lgNPs at a molar ratio of 5:1. The addition of 3,5diCQA appreciably improved the AA in a dose-dependent manner. These results shed light on the structural, physicochemical, and AA of composite β-lg or β-lgNPs-3,5diCQA non-covalent complexes, important for application as functional ingredients in food solutions as well as in the pharmaceutical industry.

Sweet potato leaf polyphenols (SPLPs) have shown potential health benefits in the food and pharmaceutical industries. Nowadays, consumption of SPLPs from animal feeds to foodstuff is becoming a trend worldwide. However, the application of SPLPs is limited by their low bioavailability and stability. β-lactoglobulin (βlg), a highly regarded whey protein, can interact with SPLPs at the molecular level to form reversible or irreversible nanocomplexes (NCs). Consequently, the functional properties and final quality of SPLPs are directly modified. In this review, the composition and structure of SPLPs and βlg, as well as methods of molecular complexation and mechanisms of formation of SPLPsβlgNCs, are revisited. The modified functionalities of SPLPsβlgNCs, especially protein conformational structures, antioxidant activity, solubility, thermal stability, emulsifying, and gelling properties including allergenic potential, digestibility, and practical applications are discussed for SPLPs future development.

Pectin and especially modified citrus pectin possesses anticancer activity. Hence, the current study investigated anticancer activity of ultrasonic-modified sweet potato pectin (SPP) on HT-29 cells to assess its potential as a cancer therapeutic agent.The effect of ultrasonic treatment on SPP molecular weight, galacturonic acid content, degree of methoxylation, and neutral sugar was investigated. Moreover, the effect of sonicated variant on human HT-29 cell proliferation was assessed by MTT assay, cell cytotoxicity, and apoptosis by Annexin V/PI flow cytometer and caspase-3 activity was studied.Sonication led up to seven-fold decrease in molecular weight. The degree of methoxylation (DM) decreased more than two-fold. Moreover, the galacturonic acid (GalA) content increased up to 92%, arabinose and galactose content increased. The SSPP inhibited cell proliferation with the IC

In this study, eucalyptus wood was subjected to thermal treatment with super-heated steam under various conditions. The effects of temperature and exposure time on the functional groups and degree of cellulose crystallinity of the eucalyptus wood (Eucalyptus grandis × Eucalyptus urophylla) were analyzed. The results showed that the thermal treatment caused significant changes in the chemical composition and structure of wood. The Fourier transform infrared spectroscopy (FTIR) absorption peaks of the hydroxyl group decreased from 3,425 to 3,250 cm−1 for all thermally treated samples. Higher treatment temperature and extended exposure led to the lower methyl levels, with almost no methyl present at 220°C. The aromatic ring first increased and then decreased with increasing temperature and exposure time. The carbonyl group maintained the same intensity, with small fluctuations, across the different thermal treatment conditions. Compared with the untreated wood sample, the X-ray diffraction peak posi...

Effects of ultrasound (US, 100, 200, 300, 400, and 500 W) and hot water (HW, 25, 40, and 55 °C) treatment combination on Rhizopus stolonifer in sweet potato tuberous roots (TRs) were investigated. US (300, 400, and 500 W) simultaneous HW (55 °C) for 10 min significantly inhibited colony diameters (from 90 mm to 80.08, 65.60, and 6.00 mm) and spores germination (p

The quest to determine and use polyphenolic compounds present in fruits and vegetables as natural antioxidants has recently attracted much attention due to their beneficial health effects. In this study, the total polyphenol content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC), antioxidant activity (AA), and individual polyphenol components of Simon No. 1, Yuzi No. 7, Shangshu 19, and Pushu 32 sweet potato cultivars (edible parts: leaf, stalk, stem, skin, and flesh) were investigated. TPC, TFC, and TAC values ranged from 440 ± 0.17-12080 ± 0.58 CAE mg/100 g DW, 94 ± 0.08-4210 ± 0.74 QE mg/100 g DW, and 7 ± 0.01-1010 ± 0.54 CGE mg/100 g DW, respectively. Yuzi No. 7 sweet potato cultivar contained significantly higher amounts of TPC, TFC, TAC, and AA in all its edible parts, followed by Pushu 32, Simon No. 1, and Shangshu 19 in that order. Regardless of the sweet potato cultivar used, TPC, TFC, and TAC of sweet potato leaves were significantly higher than those of other edible parts. High-performance liquid chromatography revealed 19 individual phenolic compounds. In general, 3,5-di- O-caffeoylquinic acid, astragalin, and cyanidin were the predominant phenolic acid, flavonoid, and anthocyanin compounds, respectively. The correlation analysis suggested that higher AA could be attributed to higher polyphenol content. Based on our results, edible parts of Yuzi No. 7 sweet potato cultivar presented the highest amounts of polyphenol content and AA suggesting the possibility of utilizing this cultivar by farmers and the food industry as a functional food product.

This chapter introduces a series of common sweet potato snacks, including sweet potato chips, roast sweet potatoes, sweet potato biscuit, dried sweet potato slices, sweet potato cakes, doughnuts, extruded sweet potato snacks, etc., and the packaging thereof. It starts by presenting an overview of sweet potato-related products, and then focuses on a series of common snack foods by presenting the concept, classification, main raw ingredients, preparation methods, and the effects on their quality of the addition of different sweet potato proportions. It then introduces the influence of packaging material and packaging systems on the stability of sweet potato snack foods. By the end of the chapter, the trends and prospects of sweet potato snack foods are presented.

This chapter introduces the main categories, individual phenolic composition, physiological functions, processing stability, and utilization of polyphenols from sweet potato roots and tops. It starts by presenting the definition and chemical composition of anthocyanins and caffeoylquinic acids (CQAs) from sweet potato roots and tops. Then the physiological functions of polyphenols from sweet potato, including antioxidant activity, antimutagenic effect, and anticancer activity, are introduced, followed by a detailed introduction into the effect of different cooking and processing conditions, including different pH values, heating temperature, and light treatment on the stability of anthocyanins and CQA s from sweet potato roots and tops. At the end of this chapter, the research and development trend of sweet potato polyphenols are presented.

This chapter introduces the extraction, purification, antioxidant activity, and individual phenolic compound composition of sweet potato leaf polyphenols. It starts by introducing sweet potato leaves and polyphenols in sweet potato leaves. It then focuses on the extraction and purification of polyphenols from sweet potato leaves, especially the purification process of polyphenols from sweet potato leaves by AB-8 macroporous adsorption resin. By the end of the chapter, the individual phenolic compound composition and antioxidant activity of the purified sweet potato leaf polyphenols are introduced, which suggest that purification by AB-8 macroporous resin was highly efficient, economic, and environmentally friendly, and has a great industrial production potential.

In this study, an inclined foam separation column was designed to effectively recover protein from sweet potato starch wastewater. The effects of the influent protein concentration, pH, air flow rate, influent volume, foaming time, and inclined column angle on foam separation performance were assessed. The optimum foam separation conditions consisted of influent protein concentration 4.51 mg/mL, pH 4, air flow rate 0.15 mL/min, influent volume 500 mL, foaming time 100 min, and inclined column angle 30°. In these conditions, protein recovery percentage and enrichment ratios were 84.1% and 1.3, respectively. The biochemical oxygen demand (BOD5) and chemical oxygen demand (CODCr) of the residual solution (620 and 950 mg/mL, respectively) were lower than those of the original (influent) solution.

The effect of heat treatment below gelatinization temperature on the susceptibility of sweet potato and cassava granular starches towards bacterial α-amylase hydrolysis was investigated. Granular starches treated at 60°C showed significantly higher degree of hydrolysis compared to those treated at 45°C, which were 17 and 32% for sweet potato and cassava starches, respectively. SEM showed a smooth granule surface for the native starches. Hydrolyzed heat treated starches at 60°C showed rougher surface and more porous granules compared to those treated at 45°C. The native and hydrolyzed heat treated starches showed no significant difference in their average granule size. Swelling power and syneresis of the starches decreased after hydrolysis. FTIR showed extensive degradation of the starches amorphous structure in hydrolyzed heat treated starches. Native and hydrolyzed heat treated cassava and sweet potato starches showed an A-type XRD pattern with strong peaks at 2θ = 15° and 23° and a dual peak at 17° and 18°. The hydrolyzed heat treated starches showed sharper peaks suggesting that hydrolysis occurred on the amorphous domains. In all, starches treated at 60°C showed higher degree of hydrolysis compared to those treated at 45°C with both exhibiting modified physicochemical characteristics.

In this chapter, dietary fiber extraction technology, such as sieve method, sieve combined enzymatic hydrolysis methods, biological methods, chemical separation method, and chemical reagent combined enzymatic hydrolysis method, are introduced. Physicochemical and functional properties of sweet potato dietary fiber, for example, viscosity, water-holding capacity, water-swelling capacity and oil-holding capacity, and physiological properties, are also evaluated. In addition, application of sweet potato dietary fiber in staple food, beverage, meat products, and functional foods are introduced. Results showed that sweet potato dietary fiber had high purity, good physicochemical and functional properties and exhibited better fat and glucose regulation. Therefore, dietary fiber extracted from sweet potato residue could be used as a fiber-rich ingredient in food and health product industries.

In the present study, the antioxidant activity of sweet potato leaf polyphenols was measured, and the effect of different pH values (3.0, 5.0, 7.0, 8.0), temperatures (55, 65, 80, 100 °C) and light treatments on sweet potato leaf-polyphenols was investigated. Results showed that the ·O2− scavenging activity of sweet potato leaf polyphenols from cultivar Jishu No.04150 was 5.84 and 6.20 times of that of tea polyphenols and grape seed polyphenols, respectively at the concentration of 20μg/mL. The oxygen radical absorbance capacity was 1.28 and 1.27 times of that of tea polyphenols and grape seed polyphenols, respectively. Sweet potato leaf polyphenols dissolved in pH 5-7 solutions showed higher retention rates of antioxidant activity. Heat treatment at 50 and 65 °C and light treatment had little effects on sweet potato leaf polyphenols. In conclusion, sweet potato leaf polyphenols possessed high antioxidant activity and processing stability, having the potential to be a new type natural antioxidant.

This review is a survey on ultrasonic application in selected carbohydrate polymers based upon available research reports. It covers a brief discussion on the fundamentals of ultrasound technology, before delving on the effects of ultrasound on specific polymers; pectin, chitin, starch, carrageenan and guar gum, their modification products and possible applications in food, pharmaceutical, biomedical and packaging sectors. Sonication generally leads to depolymerization and side chain break within molecules resulting into oligosugars. Oligosugars are widely used as prebiotics and specific delivery systems; moreover, nano sized products of sonication can be applied in diverse fields. Presently, ultrasonic is finding application in wider sectors therefore better understanding of the complex physico-chemical changes and mechanism of the action of high-intensity ultrasound and its effect on techno-functional properties of compounds would immensely fortify the application of ultrasonic technology.