Arunee Apichartsrangkoon

Combination effects of ultra-high pressure and temperature on the physical and thermal properties of ostrich meat sausage (yor)

Ostrich meat sausages (yor) were subjected to ultra-high pressures of 300, 500 and 700MPa for 40 and 60min at 40 and 60°C. Subsequently the physical properties of the products, colour, released and expressible water, gel strength and stress relaxation as well as their thermal characteristics (by differential scanning calorimeter, DSC) were determined. The effects of pressure, temperature and holding time significantly influenced the L(∗), a(∗) and b(∗) values. The amount of released plus expressible water significantly decreased with increasing pressure, temperature and holding time. The gel strength and equilibrium stress increased with increasing severity of treatment. DSC thermograms indicated that pressures of 700MPa yielded gel networks involving completely denatured protein with the ability to retain water.

Comparison of dynamic viscoelastic and physicochemical properties of pressurised and pasteurised longan juices with xanthan addition

Physical and biochemical properties of pressurised and pasteurised longan juices with various xanthan additions, such as viscoelastic behaviour, colour L (lightness), -a(*) (greenness), b(*) (yellowness), ΔE (total different colours) and BI (Browning Index) parameters, polyphenol oxidase (PPO) activity, ascorbic acid, gallic acid, ellagic acid, total phenols and antioxidant capacity (DPPH assay) were studied. Viscoelastic determination indicated that longan juice with 0.15% xanthan addition was optimal for a fruit drink. Colour parameters showed pressurised longan juice at 500 MPa was brighter and more transparent than fresh and other processed juices. PPO was completely inactivated in pasteurised juices, whereas in pressurised juices at 300 and 500 MPa, the activities were more than 100% and 95-99%, respectively. Bioactive components including ascorbic acid were significantly reduced according to treatment severities, whereas gallic and ellagic acids were relatively stable in all processed juices. Total phenols and DPPH radical-scavenging activity decreased significantly on pasteurisation, but were stable on pressurisation.

Comparison of bioactive components in pressurized and pasteurized longan juices fortified with encapsulated Lactobacillus casei 01

In this study, longan juice was subjected to a high pressure of 500 MPa for 30 min and compared with a juice pasteurized at 90°C/2 min. Probiotic Lactobacillus casei 01 was fortified into both juices and the shelf life of these products was studied. Their bioactive components such as ascorbic acid, gallic acid and ellagic acid were analyzed by High Performance Liquid Chromatography (HPLC). Total phenolic compounds and 2,2-Diphenyl-1-picrythydrazyl radical-scavenging activity were determined by colorimetric and spectrophotometric methods. It was found that the pressurized longan juice retained higher amounts of bioactive compounds than the pasteurized juice. In terms of storage stability, bioactive compounds in both processed juices decreased according to the increase in storage time. The survivability of probiotic L. casei 01 in both processed juices declined from 9 to 6 log CFU/mL after 4 weeks of storage.

Activities of free and encapsulated Lactobacillus acidophilus LA5 or Lactobacillus casei 01 in processed longan juices on exposure to simulated gastrointestinal tract.

BACKGROUND Fruit drinks containing probiotics are gaining interest in the global marketplace. For example, longan juice, containing carbohydrate and various bioactive components, is a potentially health-promoting beverage as well as probiotic carrier for human consumption. In this study, high-pressure and thermal processes were applied to eliminate competitive micro-organisms in longan juice prior to the addition of Lactobacillus acidophilus LA5 or Lactobacillus casei 01. The activities of these probiotics in a simulated gastrointestinal tract were also investigated. RESULTS Encapsulated probiotics could survive in the acidic environment of the stomach and small intestine, while the free cells were completely eliminated. In the colon experiment, the influence of encapsulated L. casei 01 on colon lactobacilli was significantly greater than that of encapsulated L. acidophilus LA5. Both encapsulated probiotics suspended in processed longan juices led to extensive increases in the formation of lactic acid and short-chain fatty acids (SCFA). Acetate was the major SCFA produced by colon bacteria, followed by propionate and butyrate. The discernible clear zone suggested that L. casei 01 provided greater antibacterial activity than L. acidophilus LA5. CONCLUSION Both encapsulated probiotics along with processed longan juice led to significant increases in colon lactobacilli, lactic acid and SCFA formation.

Effects of encapsulated Lactobacillus acidophilus along with pasteurized longan juice on the colon microbiota residing in a dynamic simulator of the human intestinal microbial ecosystem

The effect of encapsulated Lactobacillus acidophilus LA5 along with pasteurized longan juice on the colon microbiota was investigated by applying a dynamic model of the human gastrointestinal tract. Encapsulated L. acidophilus LA5 in pasteurized longan juice or sole encapsulated L. acidophilus LA5 exhibited the efficiency of colonizing the colon and enabling the growth of colon lactobacilli as well as beneficial bifidobacteria but inhibited the growth of fecal coliforms and clostridia. Moreover, these treatments gave rise to a significant increase of lactic acid and short-chain fatty acids such as acetate, propionate, and butyrate. Although acetate displayed the highest quantity, it was likely that after incorporating encapsulated L. acidophilus LA5 plus pasteurized longan juice, quantity of butyrate exceed propionate, and acetate in comparison with their controls. Denaturant gradient gel electrophoresis patterns confirmed that various treatments affected the alteration of microbial community within the simulator of the human intestinal microbial ecosystem.

Comparison of bioactive components in fresh, pressurized, pasteurized and sterilized pennywort (Centella asiatica L.) juices

The biologically active constituents of pennywort juice were analyzed by HPLC. The juice extract contained the bioactive glycosides, including asiaticoside and madecassoside. Antioxidant properties of juices were determined in terms of ferric-reducing antioxidant power assay, total polyphenol, β-carotene and ascorbic acid contents. After processing, asiaticoside, madecassoside and β-carotene in the extracted juice were relatively stable with no significant losses occurring. Pressurization could significantly retain ascorbic acid, polyphenols and antioxidant capacity than those pasteurization or sterilization. For storage assessment, asiaticoside in the processed juices was relatively stable during 4 months storage. Losses of ascorbic acid in the pressurized juice during storage were greater than in pasteurized and sterilized juice. However, the total amount of ascorbic acid retained in pressurized juice was still higher than those thermal-treated products.

Comparison of physical and chemical properties of high pressure- and heat-treated Lychee (Litchi chinensis Sonn.) in syrup

Lychee usually has white flesh, but its flesh is very sensitive to thermal and enzymatic impairment and ultimately changes in color. This investigation was intended to study the magnitude of color change in lychee by high pressure and thermal processing. The lychee was packed in syrup prior to being processed. Pressurized lychee was performed at 600 MPa at 30°C or 50°C for 20 min, while the pasteurized sample was heated at 90°C for 3 min. It was found that pressurization induced lower color L*, a* and b* values, including low anthocyanin content. For enzymatic activities, high pressure could reduce the activity of polyphenoloxidase by 33–51%, whereas pasteurization markedly reduced that activity by 90%.

Antioxidant Properties and Total Phenolics of Thua Nao (a Thai Fermented Soybean)as Affected by Bacillus-fermentation

The present investigation was aimed to observe the correlation of morphology of various isolates of Aspergillus niger on the production of Polygalacturonase (PG) and Pectin Methyl Esterase (PME) with the concept to develop a screening procedure for high enzyme producing strains of Aspergillus niger grown on agri waste . The strains were isolated from orange peel, tamarind seed powder, groundnut, carrot, pomegranate peel and apple baggasse, soil, waste water and bread. The maximum enzyme activity (PG: 2.20 ± 0 . 05μmoles/ml/min & PME: 0 . 73±0.08μmoles/ ml/min) was observed with the smallest spore size of Aspergillus niger obtained from orange peel (5.49±2.56μm). However, no correlation of conidiophore size, height of conidial stalk on pectinase production was noted. There is no report found on the level of pectinases in strain of Aspergillus niger grown on tamarind seed powder which showed considerable amount of pectinases in present study.

Efficacy of polymer coating of probiotic beads suspended in pressurized and pasteurized longan juices on the exposure to simulated gastrointestinal environment

Abstract Alginate-coated Lactobacillus acidophilus LA5 or Lactobacillus casei 01 was recoated with either 0.1–0.5% (w/v) alginate or 0.05–0.15% (w/v) poly-L-lysine (PLL) plus 0.2% (w/v) alginate or 5–15% (w/v) gelatin, after which they were determined for survivability in gastric or bile longan juices. The morphology of encapsulated probiotic cells illustrated that recoated beads with 0.5% alginate showed a more compact surface and a greater protective effect than other recoating materials. The recoated beads with 0.5% alginate and 0.05–0.15% PLL plus 0.2% alginate of both strains showed the highest viability in gastric longan juice. In bile longan juice, only 0.5% alginate showed the best protection for both recoated beads. When considering the storage stability, encapsulated L. acidophilus LA5 exhibited a higher viable count than those of the free cells, whereas L. casei 01 showed equivalent viability of both free and double-coated cells. Based on the impact of pressurization or pasteurization, both processed juices gave rise to equivalent survivability of the probiotic cells during storage.

Effect of encapsulated Lactobacillus casei 01 along with pressurized-purple-rice drinks on colonizing the colon in the digestive model.

The objective of the study was to examine the influence of encapsulated Lactobacillus casei 01 combining with two types of pressurized-purple-rice drinks on colonizing the colon using a simulator of the human intestinal microbial ecosystem. Subsequently, the metabolic products of colon bacteria and various microflora were determined. The finding revealed that acetate which was the predominant short-chain fatty acid (SCFA) was found in both proximal and distal colons, while the combination of encapsulated L. casei 01 and germinated-purple-rice drinks gave rise to highest formation of SCFA. Significant impact of rice drinks could be observed on reducing ammonia production. The quantitative polymerase chain reaction analysis demonstrated that encapsulated L. casei 01 and encapsulated L. casei 01 plus rice drinks markedly increased concentration of colon lactobacilli and bifidobacteria by 2 and 1 log 16S rRNA gene copies/mL, respectively. On the contrary, undesirable bacteria such as clostridia and coliforms were significantly reduced with the influence of encapsulated L. casei 01 plus purple-rice drinks.