Shaoxiao Zeng

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.

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.

Properties of lotus seed starch–glycerin monostearin complexes formed by high pressure homogenization

Starch-lipid complexes were prepared using lotus seed starch (LS) and glycerin monostearate (GMS) via a high pressure homogenization (HPH) process, and the effect of HPH on the physicochemical properties of LS-GMS complexes was investigated. The results of Fourier transform infrared spectroscopy and complex index analysis showed that LS-GMS complexes were formed at 40MPa by HPH and the complex index increased with the increase of homogenization pressure. Scanning electron microscopy displayed LS-GMS complexes present more nest-shape structure with increasing homogenization pressure. X-ray diffraction and differential scanning calorimetry results revealed that V-type crystalline polymorph was formed between LS and GMS, with higher homogenization pressure producing an increasingly stable complex. LS-GMS complex inhibited starch granules swelling, solubility and pasting development, which further reduced peak and breakdown viscosity. During storage, LS-GMS complexes prepared by 70-100MPa had higher Avrami exponent values and lower recrystallization rates compared with native starch, which suggested a lower retrogradation trendency.

Medium Optimization and Fermentation Kinetics for κ-Carrageenase Production by Thalassospira sp. Fjfst-332

Effective degradation of κ-carrageenan by isolated Thalassospira sp. fjfst-332 is reported for the first time in this paper. It was identified by 16S rDNA sequencing and morphological observation using Transmission Electron Microscopy (TEM). Based on a Plackett–Burman design for significant variables, Box–Behnken experimental design and response surface methodology were used to optimize the culture conditions. Through statistical optimization, the optimum medium components were determined as follows: 2.0 g/L κ-carrageenan, 1.0 g/L yeast extract, 1.0 g/L FOS, 20.0 g/L NaCl, 2.0 g/L NaNO3, 0.5 g/L MgSO4·7H2O, 0.1 g/L K2HPO4, and 0.1 g/L CaCl2. The highest activity exhibited by Thalassospira sp. fjfst-332 was 267 U/mL, which makes it the most vigorous wild bacterium for κ-carrageenan production. In order to guide scaled-up production, two empirical models—the logistic equation and Luedeking–Piretequation—were proposed to predict the strain growth and enzyme production, respectively. Furthermore, we report the fermentation kinetics and every empirical equation of the coefficients (α, β, X0, Xm and μm) for the two models, which could be used to design and optimize industrial processes.

C‐type starches and their derivatives: structure and function

The C‐type starches are widely distributed in seeds or rhizomes of various legumes, medicinal plants, and crops. These carbohydrate polymers directly affect the application of starchy plant resources. The structural and crystal properties of starches are crucial parameters of starch granules, which significantly influence their physicochemical and mechanical properties. The unique crystal structure consisting of both A‐ and B‐type polymorphs endows C‐type starches with specific crystal adjustability. Furthermore, large proportions of resistant starches and slowly digestible starches are C‐type starches, which contribute to benign glycemic response and proliferation of gut microflora. Here, we review the distribution of C‐type starches in various plant sources, the structural models and crystal properties of C‐type starches, and the behavior and functionality relevant to modified C‐type starches. We outline recent advances, potential applications, and limitations of C‐type starches in industry, aiming to provide a theoretical basis for further research and to broaden the prospects of its applications.

Ultrasound-Assisted Rehydration of Dried Sea Cucumber (Stichopus japonicus) – Kinetics

Abstract Sea cucumbers are popular traditional tonic foods in Asia and the Middle East and are often dried for storage or sale. Rehydration of dried sea cucumber is a necessary step before further processing. The kinetics for ultrasound-assisted rehydration were mathematically described using mechanistic (Fick’s diffusion) and empirical (Peleg’s equation, Weibull model) models. The effective diffusivities of water transport with ultrasound were in the range of 0.182 mm2 min–1–0.197 mm2 min–1, which was greater than the value of the control, at 0.179 mm2 min–1, considering Fick’s diffusion. Peleg’s equation was concluded to be the best model to predict the ultrasound-assisted rehydration of dried sea cucumber. Its rehydration efficiency was increased 16-fold by ultrasound and rehydration time was reduced up to 45 h, the sea cucumbers did not show any negative effects on their texture properties after rehydration.

Slowly digestible properties of lotus seed starch-glycerine monostearin complexes formed by high pressure homogenization

Starch-lipid complexes were prepared using lotus seed starch (LS) and glycerin monostearate (GMS) via a high-pressure homogenization process, and the effect of high pressure homogenization (HPH) on the slow digestion properties of LS-GMS was investigated. The digestion profiles showed HPH treatment reduced the digestive rate of LS-GMS, and the extent of this change was dependent on homogenized pressure. Scanning electron microscopy displayed HPH treatment change the morphology of LS-GMS, with high pressure producing more compact block-shape structure to resist enzyme digestion. The results of Gel-permeation chromatography and Small-angle X-ray scattering revealed high homogenization pressure impacted molecular weight distribution and semi-crystalline region of complexes, resulting in the formation of new semi-crystalline with repeat unit distance of 16-18 nm and molecular weight distribution of 2.50-2.80 × 105 Da, which displayed strong enzymatic resistance. Differential scanning calorimeter results revealed new semi-crystalline lamellar may originate from type-II complexes that exhibited a high transition temperature.