Mohammed Abdalbasit A. Gasmalla

Stevia rebaudiana Bertoni: An alternative Sugar Replacer and Its Application in Food Industry

Stevia rebaudiana Bertoni is a branched bushy shrub of the Asteraceae family, native to the Amambay region in the northeast of Paraguay. Stevioside and rebaudioside A are the main sweetening compounds of interest, which are commercially produced by both chemical and physical processes. S. rebaudiana has a great potential as a new agricultural crop since consumer demand for health promoting foods is increasing, and proximate analysis has shown that Stevia also contains substantial amounts of proteins, potassium, and other essential nutrients. Stevia can be taken in as a carbohydrate diet source without calories. This paper provides an overview of structure and properties of stevioside, various extraction techniques, applicability in food industry, and recent technological advances achieved.

Effect of ultrasonic treatment on total phenolic extraction from Lavandula pubescens and its application in palm olein oil industry.

The aims of the current study were to evaluate the best technique for total phenolic extraction from Lavandula pubescens (Lp) and its application in vegetable oil industries as alternatives of synthetic food additives (TBHQ and BHT). To achieve these aims, three techniques of extraction were used: ultrasonic-microwave (40 kHz, 50 W, microwave power 480 W, 5 min), ultrasonic-homogenizer (20 kHz, 150 W, 5 min) and conventional maceration as a control. By using the Folin-Ciocalteu method, the total phenolic contents (TPC) (mg gallic acid equivalent/g dry matter) were found to be 253.87, 216.96 and 203.41 for ultrasonic-microwave extract, ultrasonic-homogenizer extract and maceration extract, respectively. The ultrasonic-microwave extract achieved the higher scavenger effect of DPPH (90.53%) with EC50 (19.54 μg/mL), and higher inhibition of β-carotene/linoleate emulsion deterioration (94.44%) with IC50 (30.62 μg/mL). The activity of the ultrasonic-microwave treatment could prolong the induction period (18.82 h) and oxidative stability index (1.67) of fresh refined, bleached and deodorized palm olein oil (RBDPOo) according to Rancimat assay. There was an important synergist effect between citric acid and Lp extracts in improving the oxidative stability of fresh RBDPOo. The results of this work also showed that the ultrasonic-microwave assisted extract was the most effective against Gram-positive and Gram-negative strains that were assessed in this study. The uses of ultrasonic-microwave could induce the acoustic cavitation and rupture of plant cells, and this facilitates the flow of solvent into the plant cells and enhances the desorption from the matrix of solid samples, and thus would enhance the efficiency of extraction based on cavitation phenomenon.

Bioactive Peptides Derived from Seaweed Protein and Their Health Benefits: Antihypertensive, Antioxidant, and Antidiabetic Properties

Cardiovascular diseases and diabetes are the biggest causes of death globally. Therefore, prevention of these diseases is a focus of pharmaceuticals and functional food manufacturers. This review summarizes recent research trends and scientific knowledge in seaweed protein-derived peptides with particular emphasis on production, isolation and potential health impacts in prevention of hypertension, diabetes and oxidative stress. The current status and future prospects of bioactive peptides are also discussed. Bioactive peptides have strong potential for use in therapeutic drug and functional food formulation in health management strategy, especially cardiovascular disease and diabetes. Seaweeds can be used as sustainable protein sources in the production of these peptide-based drugs and functional foods for preventing such diseases. Many studies have reported that peptides showing angiotensin converting enzyme inhibition, antihypertensive, antioxidative and antidiabetics activities, have been successfully isolated from seaweed. However, further research is needed in large-scale production of these peptides, efficient isolation methods, interactions with functional foods and other pharmaceuticals, and their ease to digestion in in vivo studies and safety to validate the health benefits of these peptides.

Lactulose production from efficient isomerization of lactose catalyzed by recyclable sodium aluminate

An efficient strategy for the synthesis of high-purity lactulose through chemical isomerization of lactose was developed using recyclable catalyst sodium aluminate. Maximum yield of 85.45±1.79% was obtained from 35% (w/v) of lactose using a 1:1M ratio of NaAlO2-lactose after reaction at 60°C and pH 12 for 50min, with a purity ratio (Pu) of approximately 95%. Al(OH)3 precipitation from lactulose syrup through pH adjustment showing a superior decolorizing efficiency was implemented, which simplified the removal of catalyst and provided a convenient approach to achieve catalyst recovery. After dilution by 5 folds, nearly 98.5% of catalyst was removed through centrifugation and 85.50±1.81% of lactulose was recovered. Modified recycle use of catalyst without lactulose loss was carried out, after five consecutive recycles, total yield of lactulose (TYLactulose) and new yield of lactulose (NYLactulose) were of 80.44±1.05% and 73.87±0.50%, respectively, reflecting a high stability by using this recyclable methodology.

Characterization of a cold‐adapted esterase and mutants from a psychotolerant Pseudomonas sp. strain

A cold‐adapted esterase‐producing strain named T1‐39 was isolated from Glacier No. 1, Tianshan, Peoples Republic of China and identified as Pseudomonas sp. from 16S rRNA sequence analysis. The esterase (EstT1‐39) secreted by this strain preferentially hydrolyzed esters of glycerol with short‐ and medium‐chain fatty acids. Mutants of T1‐39 were generated by the atmospheric and room temperature plasma method and screened for enhanced esterase activity. Among all the mutants, strain TB11 had 4.45‐fold higher esterase productivity than T1‐39, with high genetic stability over 10 generations of continuous cultivation. Maximum activity of EstT1‐39 and EstTB11 was observed at 30 ℃, pH 9.0 and 25 ℃, pH 8.5, respectively. EstTB11 was thermally more stable (50 ℃ for 1 H) and active over a broader pH range than EstT1‐39. EstTB11 also retained 38% of its maximal activity at 0 ℃ and was found to be able to hydrolyze milk fats into short‐ and medium‐chain fatty acids at 4 ℃. The characteristics of EstT1‐39 made it a cold‐adapted enzyme and the EstTB11 from the mutant, with its higher activity at lower temperatures, may be suitable for the production of aromas and flavors in the dairy industry.

Health benefits of milk and functional dairy products

1School of Food Science and Technology, Jiangnan University, China 2Department of Nutrition & Food technology, Faculty of Science and Technology, Omdurman Islamic University, Sudan 3Departmentof Food process Engineering, Addis Ababa Science and Technology University, Ethiopia 4Department of Animal Science, Faculty of Agricultural Sciences, University of Gezira, Sudan 5Department of Food Processing Engineering, Faculty of Engineering, Al Imam Almahdi University, Sudan