Effect of Ultrasonic-Assisted Enzymatic Hydrolysis on Functional Properties and Antioxidant Activity of Eri Silkworm Pupa Protein Isolate.

Philosamia ricini (Eri silkworm) pupa protein isolate (EPI) was utilized to prepare pupa protein hydrolysate (EPIH) through enzymatic hydrolysis. Additionally, the isolate underwent ultrasonic treatment at 20 kHz to become ultrasound pretreated EPI (EPIU), which was then enzymatically hydrolyzed to obtain ultrasound pretreated protein hydrolysate (EPIUH). The physicochemical properties of these samples were investigated, including molecular weight, solubility, foaming and emulsion properties, water- and oil-holding capacity, antioxidant activity, and color. When compared to EPI (used as the control), EPIU exhibited a high degree of hydrolysis at 20 minutes (DH = 29.24%). At a total process time of 20 minutes, the degree of hydrolysis for EPIH, EPIU, and EPIUH was found to be 13%, 29%, and 41%, respectively. SDS-PAGE analysis indicated no difference in molecular weight between EPI and EPIU (11-75 kDa). However, the molecular weight profiles of EPIH and EPIUH were reduced (8-45 kDa), resulting in changes in protein functionalities. The high DH value contributed to the enhancement of antioxidant activity, solubility, emulsion capacity, emulsion stability, and foam capacity of the protein isolate at pH 7. Furthermore, the ultrasonic pretreatment of the protein hydrolysate increased the lightness of the protein powder by reducing the enzyme activity of the polyphenol oxidase (PPO). These results suggest that ultrasonic pretreatment of the protein hydrolysate could be applied to improve the properties of Eri silkworm pupa protein for use in the food and beverage industry, such as protein-rich beverages or salad dressings.

Characteristics of Amorphophallus konjac as indicated by its genome.

Amorphophallus konjac, belonging to the genus Amorphophallus of the Araceae family, is an economically important crop widely used in health products and biomaterials. In the present work, we performed the whole-genome assembly of A. konjac based on the NovaSeq platform sequence data. The final genome assembly was 4.58 Gb with a scaffold N50 of 3212 bp. The genome includes 39,421 protein-coding genes, and 71.75% of the assemblies were repetitive sequences. Comparative genomic analysis showed 1647 gene families have expanded and 2685 contracted in the A. konjac genome. Likewise, genome evolution analysis indicated that A. konjac underwent whole-genome duplication, possibly contributing to the expansion of certain gene families. Furthermore, we identified many candidate genes involved in the tuber formation and development, cellulose and lignification synthesis. The genome of A. konjac obtained in this work provides a valuable resource for the further study of the genetics, genomics, and breeding of this economically important crop, as well as for evolutionary studies of Araceae family.

Modification of Konjac Biodegradable Material Using Deacetylation and Reinforcement Process for Its Applications in Food Packaging.

Common konjac flour, especially of low grade, is a waste material produced in large quantities during purification of konjac glucomannan (KGM). It contains impurities, particularly oxalate salts, which irritate and may cause kidney stones. Konjac flour has glucomannan as a main component. Glucomannan is characterized by low crystallinity, high thermostability, and the ability to form a strong gel. Subsequently, glucomannan has good potential for the production of biodegradable material. However, its high-water affinity limits its use in packaging. The deacetylated by thermal forming process and reinforced konjac flour with 15% and 20% of microcrystalline cellulose showed improved water absorption and thermal properties of the specimen. Moreover, the thermal forming process resulted in the reduction of soluble oxalate. Therefore, due to the conditions used in this experiment, the material will be stronger, more waterproof properties, and more highly resistant to temperatures, so it is suitable to be used as a packaging that is environmentally friendly.

Risk assessment of heavy metals in marine fish and seafood from Kedah and Selangor coastal regions of Malaysia: a high-risk health concern for consumers.

The heavy metals namely Fe, As, Cu, Cd, and Pb were investigated in two marine fishes silver pomfret (Pampus argentus) and torpedo scad (Megalaspis cordyla), and three seafoods sibogae squid (Loligo sibogae), Indian white prawn (Fenneropenaeus indicus), and mud crab (Scylla serrata) by using inductively coupled plasma spectrophotometer (ICP-MS) from two renowned fish harvesting coastal area of Malaysia named as Kedah and Selangor. Among the target heavy metals, highest mean concentration of As and Fe were found in Scylla serrata (72.14±7.77 µg/g) in Kedah and Megalaspis cordyla (149.40±2.15 µg/g) in Selangor. Pearson's correlation results showed As-Fe-Cd-Cu originated from the same source. Maximum estimated daily intake (EDI) values of Scylla serrata were found 175.25 µg/g/day and 100.81 µg/g/day for child in both Kedah and Selangor areas respectively. Hazard quotient (HQ) and hazard index (HI) results revealed that local consumers of Kedah and Selangor will face high chronic risk if they consume Scylla serrata, Fenneropenaeus indicus, and Megalaspis cordyla on regular basis in their diet. Carcinogenic risk results suggested that all the studied species pose very high risk of cancer occurrences to the consumers in both areas. Therefore, it could be recommended that consumers should be aware when they are consuming these marine species since they can pose serious health risk associated with prolonged consumption.

Nutritional profile of wild, pond-, gher- and cage-cultured tilapia in Bangladesh.

The proximate, minerals, amino acid and fatty acid composition of wild, pond-, gher- and cage-cultured tilapia in Bangladesh were evaluated and varied significantly (p < 0.05). The major component of the tilapia was moisture (79.12%-81.36%), followed by protein (14.93%-16.03%), lipid (0.59%-2.35%), carbohydrate (1.23%-1.51%), fibre (0.47%-0.88%), ash (0.31%-0.53%); the energy value was between 97.62 and 126.73 kcal/100 g. Macro-nutrients and micro-nutrients were detected in following order: K > Na > Mg > Ca and Fe > Mn, respectively in all the tilapia and the ratio of Na/K was <1. Essential amino acids, leucine (1.47-1.56 g/100 g) and lysine (1.66-1.74 g/100 g), were the predominant amino acids in tilapia, followed by non-essential amino acids, aspartic acid (1.72-1.84 g/100 g) and glutamic acid (2.88-3.07 g/100 g). Saturated palmitic acid (25.4%-35.54%), monounsaturated elaidic acid (31.51%-35.63%) and polyunsaturated linolenic acid (17.69%-22.57%) were the main fatty acids found in tilapia. The desirable protein percentage, Na/K ratio, the presence of essential amino acids, leucine and lysine, n-3 and n-6 fatty acid contents proved that the consumption of wild, pond-, gher- and cage-cultured tilapia are beneficial to human health and could be recommended to prevent different diseases particularly of cardiovascular type.

Konjac glucomannan hydrolysate: A potential natural coating material for bioactive compounds in spray drying encapsulation.

This research aimed to develop a suitable coating material for encapsulating a plant bioactive compound via spray drying. A suitable process for modifying the rheological property of konjac glucomannan (KGM) solution by enzymatic treatment was developed. A plant bioactive compound, andrographolide, was selected to use as core material. Mannanase (1500 units of enzyme) was used in the treatment of KGM solution. The concentration of KGM solution was varied from 9 to 18% (w/w). It was found that 12% (w/w) was the optimum KGM concentration that could be hydrolyzed to a viscosity of <100 mPa·s. HPLC analysis of hydrolyzed solution found a fair amount of DP4-DP7 oligosaccharides (where DP is degree of polymerization) were obtained. The solution was then used as coating material in spray drying with inlet air temperature of 170°C and outlet air temperature of 85°C. It was found that 12% (w/w) konjac glucomannan hydrolysate (KGMH) was suitable for coating 2% (w/w) andrographolide. Its efficiency of encapsulation was also higher than that of KGMH combined with gamma-cyclodextrin or beta-cyclodextrin. This study revealed a great potential of using KGMH solution for pharmaceutical and food industries in the spray drying encapsulation process.

Quantitative determination of non-starch polysaccharides in foods using Gas Chromatography with flame ionization detection.

A gas chromatographic method was developed for the quantitative determination of the monosaccharides of the soluble, insoluble fractions and the total non-starch polysaccharides (NSPs) content in foods with fat contents of less than 5%. Sample preparation involved enzymatic removal of starch and acid hydrolysis of the NSP to their constituent sugars. The alditol acetate derivatives were analysed on a wide bore capillary column with detection by flame ionization. The method was accurate, with recovery of spiked samples between 93.6% and 102.7% for intra-day analysis and between 93.2% and 104.7% for inter-day analysis. Repeatability was excellent; RSD values from 0.1 to 4.4% and 0.2 to 5.7% were observed from intra-day analysis and inter-day analysis, respectively. The peaks for all neutral sugars were sharp and separation was at baseline resolution with no interfering or co-eluting peaks.

The Change of Total Anthocyanins in Blueberries and Their Antioxidant Effect After Drying and Freezing.

This study examined the effects of freezing, storage, and cabinet drying on the anthocyanin content and antioxidant activity of blueberries (Vaccinium corymbosum L). Fresh samples were stored for two weeks at $\5^\circ$ C while frozen samples were kept for up to three months at $-20^\circ$ C. There were two drying treatments, one including osmotic pretreatment followed by cabinet drying and the other involving only cabinet drying. Total anthocyanins found in fresh blueberries were $7.2 \pm 0.5$ mg/g dry matter, expressed as cyanidin 3-rutinoside equivalents. In comparison with fresh samples, total anthocyanins in untreated and pretreated dried blueberries were significantly reduced to $4.3 \pm 0.1$ mg/g solid content, 41% loss, and $3.7 \pm 0.2$ mg/g solid content, 49% loss, respectively. Osmotic treatment followed by a thermal treatment had a greater effect on anthocyanin loss than the thermal treatment alone. In contrast, the frozen samples did not show any significant decrease in anthocyanin level during three months of storage. Measurement of the antioxidant activity of anthocyanin extracts from blueberries showed there was no significant difference between fresh, dried, and frozen blueberries.