Baodong Zheng

Optimization of ultrasonic-assisted extraction of pomegranate (Punica granatum L.) seed oil.

The effectiveness of ultrasonic-assisted extraction (UAE) of pomegranate seed oil (PSO) was evaluated using a variety of solvents. Petroleum ether was the most effective for oil extraction, followed by n-hexane, ethyl acetate, diethyl ether, acetone, and isopropanol. Several variables, such as ultrasonic power, extraction temperature, extraction time, and the ratio of solvent volume and seed weight (S/S ratio) were studied for optimization using response surface methodology (RSM). The highest oil yield, 25.11% (w/w), was obtained using petroleum ether under optimal conditions for ultrasonic power, extraction temperature, extraction time, and S/S ratio at 140 W, 40 °C, 36 min, and 10 ml/g, respectively. The PSO yield extracted by UAE was significantly higher than by using Soxhlet extraction (SE; 20.50%) and supercriti cal fluid extraction (SFE; 15.72%). The fatty acid compositions were significantly different among the PSO extracted by Soxhlet extraction, SFE, and UAE, with punicic acid (>65%) being the most dominant using UAE.

Structural characteristics and crystalline properties of lotus seed resistant starch and its prebiotic effects

Lotus seed resistant starch (LRS) is a type of retrograded starch that is commonly known as resistant starch type 3 (RS3). The structural and crystalline properties of unpurified LRS (NP-LRS3), enzyme purified LRS after drying (GP-LRS3), and enzyme purified LRS (ZP-LRS3) were characterized. The result showed that the molecular weights of NP-LRS3, GP-LRS3, and ZP-LRS3 were 0.102 × 10(6), 0.014 × 10(6), and 0.025 × 10(6)Da, respectively. Compared with native starch and high amylose maize starch (HAMS), LRS lacked the polarization cross and the irregularly shaped LRS granules had a rougher surface, B-type crystal structure, and greater level of molecular order. The FT-IR measurements indicated no differences in the chemical groups. Analysis by (13)C NMR indicated an increased propensity for double helix formation and higher crystallinity in LRS than in the two other types of starch. Moreover, LRS was more effective than either glucose or HAMS in promoting the proliferation of bifidobacteria.

Effects of different drying methods on the product quality and volatile compounds of whole shiitake mushrooms

Various drying methods play important roles in the preservation of foods. However, how the different drying methods affect the quality of some foods is not clear. This paper evaluates the effects of hot air, vacuum, microwave, and microwave vacuum drying techniques on important qualities and volatile compounds of whole shiitake (Lentinus edodes) mushrooms. These four drying methods resulted in a significantly (p<0.05) increase in the content of total free amino acids and the relative content of sulfur compounds of dried products. Microwave vacuum drying helped to maintain larger amounts of taste-active amino acids, and improved nutrient retention and color attributes. Furthermore, the uniform honeycomb network created by microwave vacuum drying along with a less collapsed structure of dried samples can be used to explain the observed high rehydration ratio. Therefore, microwave vacuum drying should be a potential method for obtaining high-quality dried mushrooms.

Structural and physicochemical properties of lotus seed starch treated with ultra-high pressure

Aqueous lotus seed starch suspensions (15%, w/w) were subjected to ultra-high pressure treatment (UHP, 100-600 MPa) for 30 min. The effects of UHP treatment on the structural and physicochemical properties of starch were investigated. The SEM and laser diffraction particle size analysis revealed that UHP treatment affected the shape and size distribution of starch granules. The morphological structure of starch was completely destroyed at 600 MPa, indicating complete gelatinization. Analysis of HPSEC-MALLS-RI suggested that the dispersity index of UHP-treated starch were decreased from 1.28 to 1.11. According to XRD analyses, UHP treatment converted native starch (C-type) into a B-type pattern. The swelling power and solubility presented a significant decrease at 85 and 95 °C, but opposite trends were found at 55-75 °C. The DSC results indicated a reduction in gelatinization temperatures and enthalpy with increasing pressure treatment. The RVA viscograms revealed that UHP-treated starch showed a decreased breakdown and setback viscosity, reflecting lower retrogradation tendency compared to native starch.

Structural characteristics and physicochemical properties of lotus seed resistant starch prepared by different methods

Lotus seed resistant starch (LRS) is commonly known as resistant starch type 3 (LRS3). The objective of this study was to investigate the effect of different preparation methods on the structural characteristics and physicochemical properties of LRS3. The molar mass of LRS3 prepared by autoclaving method (GP-LRS3) and ultrasonic-autoclaving method (UP-LRS3) was mainly distributed in the range 1.0 × 10(4)-2 × 10(4) g/mol while a decrease of LRS3 prepared by microwave-moisture method (MP-LRS3) was observed. The particle of MP-LRS3 was smaller and relatively smoother while UP-LRS3 was bigger and rougher compared to GP-LRS3. Among these samples, GP-LRS3 exhibited the highest degree of ordered structure and crystallinity, the amorphous region of MP-LRS3 was the biggest and UP-LRS3 displayed the highest degree of double helical structure. Additionally, MP-LRS3 displayed the strongest solubility and swelling power while UP-LRS3 exhibited the strongest iodine absorption ability and thermostability, which were affected by their structural characteristics.

Characterization and hypoglycemic activity of a β-pyran polysaccharides from bamboo shoot (Leleba oldhami Nakal) shells.

The bamboo shoot (Leleba oldhami Nakal) shell is a by-product during bamboo shoot processing. It is a cheap and available resource for dietary polysaccharides. Herein, a novel polysaccharide BSSP2a was isolated and characterized from the bamboo shoot shell polysaccharides, and it was identified as a homogeneous highly-branched beta type pyran polysaccharide with a molecular weight of 1.63×10(4)kDa, which consisted of arabinose, xylose, mannose, glucose and galactose at a molar ratio of 20.4:4.9:1:3.4:20.6. The crude polysaccharides (BSSP) from the bamboo shoots shell showed hypoglycemic activity on the high fat diet and streptozotocin induced diabetic mice in a dose-dependent manner. The administration of high dose BSSP (400mg/kg) improved body weight loss and serum insulin loss, and significantly decreased the blood glucose level, serum triglycerides as well as total cholesterol levels by 48.7%, 34.8% and 26.5%, respectively. The results highlight the potential of the bamboo shoot shell polysaccharides as a natural anti-diabetic agent.

Structural characterization of a novel neutral polysaccharide from Lentinus giganteus and its antitumor activity through inducing apoptosis.

A novel neutral polysaccharide (LGPS-1), with a molecular weight of 1.547×10(5)Da, was isolated from Lentinus giganteus by precipitation and purification. The monosaccharides included d-mannose (Man), d-glucose (Glc) and d-galactose (Gal) with a molar ratio of 3.0:4.1:7.1. The backbone of LGPS-1 was composed of 1,6-Galp and 1,3,6-Manp whereas the branches were composed of 1,6-Glcp and 1-Glcp. The anticancer efficacy of LGPS-1 was assessed using HepG2 hepatocellular carcinoma cells. The results showed that LGPS-1 inhibited the proliferation of HepG2 cells and also induced the activation of caspase-3, and cleavage of PARP-1. Western blot analysis revealed that LGSP-1 significantly induced a loss of mitochondrial membrane potential (Δym), increased the ratio of Bax/Bcl-2, promoted the release of cytochrome c into cytoplasm as well as inhibited the phosphorylation of Akt in HepG2 cells. These findings suggest that LGPS-1 induced apoptosis in HepG2 cells through intrinsic mitochondrial apoptosis and PI3K/Akt signaling pathways.

Nutritional composition, physiological functions and processing of lotus (Nelumbo nucifera Gaertn.) seeds: a review

Nelumbo nucifera Gaertn. has a relatively wide geographical distribution and biological diversity; various lotus parts have excellent food and medicinal values. Lotus seeds, which are currently the oldest known plant seeds, contain many functional ingredients. They can be eaten raw or cooked, and are often added to foods as ingredients or supplements. Many naturally occurring ingredients isolated from lotus seeds are certified to be multiple functional compounds, such as polyphenols, protein, polysaccharides. Proteins and carbohydrates are the main nutrients of lotus seeds. Low fat content and good proportion of amino acids confer to lotus seeds unique nutritional values that have attracted increasing attention around the world: multiple studies have assessed the functional components of lotus seeds. The bioactivity of ingredients from lotus seeds in vitro and in vivo include antioxidant activity, hypoglycemic, immunomodulatory, antibacterial, anti-inflammatory, analgesic effects as well as gastrointestinal regulation. Lotus seeds show prospective application in function food area and traditional medicine research. Furthermore, structure–activity relationship of functional compounds from lotus seeds will attracts much more interests in recent years. This work briefly reviews the nutrition composition, physiological functions and processing methods of lotus seeds, describing the impact of the latter on nutrient preservation. In addition, this review addresses the recent progresses made in this area and discusses the potential applications and limitations.

Protective Effects of Alkaloid Compounds from Nelumbinis Plumula on tert-Butyl Hydroperoxide-Induced Oxidative Stress

This study was conducted to investigate the effect of Nelumbinis Plumula total alkaloid (NPA) and its main alkaloid components on oxidative stress induced by tert-butyl hydroperoxide (t-BHP) in the human hepatocellular HepG2 cell line. According to HPLC analysis, several major alkaloid compounds such as liensinine, isoliensinine and neferine were present in NPA. The cytotoxic effects in 0.55 mM t-BHP-induced HepG2 cells were significantly inhibited by NPA and the major compound in NPA, neferine, showed the strongest activities. The protective effect of neferine against oxidative stress induced by t-BHP may be associated with decreased ROS formation, TBARS generation, LDH release and increased GSH levels, suggesting their involvement of the cytoprotective on oxidative stress. The effects were comparable with quercetin, which was used as positive control. Overall, total alkaloid and alkaloid compounds from Nelumbinis Plumula displayed a significant cytoprotective effect against oxidative stress. Further study is needed to elucidate the relationship between the chemical structures of the components in NPA and their protective effect on oxidative stress.

Effect of Microwave Irradiation on the Physicochemical and Digestive Properties of Lotus Seed Starch

The objective of this study is to investigate the effect of microwave irradiation on the physicochemical and digestive properties of lotus seed starch. The physicochemical properties of lotus seed starch were characterized by light microscopy, (1)H NMR, FT-IR spectroscopy, and HPSEC-MALLS-RI. The starch-water interaction and crystalline region increased due to the changed water distribution of starch granules and the increase of the double-helix structure. The swelling power, amylose leaching, molecular properties, and radius of gyration reduced with the increasing microwave power, which further affected the sensitivity of lotus seed starch to enzymatic degradation. Furthermore, the resistant starch and slowly digestible starch increased with the increasing microwave irradiation, which further resulted in their decreasing hydrolysis index and glycemic index. The digestive properties of lotus seed starch were mainly influenced by the reduced branching degree of amylopectin and the strong amylose-amylose interaction.