The Physical and Mechanical Properties of Agar and Carrageenan Film Incorporated with Hydrolysate-Konjac Glucomannan

The effect of combine-polysaccharides ratio on the properties of edible film was studied. The objective of this research is to investigate the physical and mechanical properties of polysaccharide film that incorporated with hydrolysate-konjac glucomannan. Film samples containing agar (0-100%), carrageenan (0-50%), or hydrolysate-konjac glucomannan (HKG) (0-50%) at different calculated ratios of mixing using mixture design and adding glycerol as a plasticizer were prepared. The results showed that viscosity of the film solution was decreased while adding HKG. The addition of HKG could increase thickness and moisture content but could decrease the transparency of the film. The result showed that the highest water vapor permeability (WVP) came from film which contained mixture of HKG and carrageenan (1.22x10-5 g mm m-2 s-1 Pa-1). The lowest WVP came from agar, while the mixture of HKG and carrageenan had the lowest oxygen permeability (OP) (5.84x10-8 mm cm3 m-2 s-1 Pa-1). The mechanical properties in terms of tensile strength and load at the maximum of the film were decreased as addition of HKG but were increased with agar adding. The elongation at break was increased with the mixture of HKG and carrageenan, and the mixture HKG, carrageenan, and agar (32.42%), respectively. In conclusion, the calculated mixture ratio from mixture design contributed to different physical and mechanical properties of the polysaccharide film, depending on their concentrations and type of polysaccharide in the film solution. The mixture of HKG, carrageenan, and agar could be applied for food packaging. However, the barrier behavior of the film need to be improved in future research.

The Effect of Mixed Hydrocolloids and Protein Isolate Film on the Physical-Mechanical Properties of Film and the Survivability of Lacticaseibacillus paracasei and Bifidobacterium animalis

The effect of mixed hydrocolloids and protein isolate film on its physical-mechanical properties and the survival rate of Lacticaseibacillus paracasei and Bifidobacterium animalis that were added into the films were studied. The results showed the shear thinning behavior of the film solution. The agar mixed solution exhibited the highest apparent viscosity. The thickness and transparency of the film were varied from 0.0547±0.005 to 0.102±0.007 mm and 9.03±0.93 to 32.65±4.55, respectively. The films that consisted of soy protein isolate (SPI) had the highest thickness and the lowest transparency. The high mechanical properties were observed in the agar-incorporated film. Using glycerol as a plasticizer had higher elongation at break than using sorbitol. The survivability of each probiotic bacteria was found ranging from 41.84±0.46% to 92.58±2.20%, and the highest survivability was found in the film-incorporated protein isolate, while it was not found any probiotic bacteria in the agar film without protein.  However, B. animalis had a greater survival rate in mixed film than L. paracasei. In summary, the application of probiotic film would depend on the component of mixed films and probiotic strains that affected physical-mechanical properties of the film and probiotic survivability

Comparison of physicochemical and sensory evaluations of polymeric ONS utilizing tapioca maltodextrin DE7 or DE19 as carbohydrate source

Tapioca-starch maltodextrin (TM) has recently been developed for various Dextrose Equivalents (DE), which may influence the physicochemical characteristics of a product. This study aimed to develop nutritionally complete oral nutrition supplement (ONS) by using TM DE7 and DE19 as carbohydrate sources. Two polymeric nutritionally complete ONS formulas containing TM, whey protein isolate, rice bran oil, vitamins, and minerals, were developed. Their difference was that one contained TM DE7 and the other DE19. Physical properties and sensory acceptance were evaluated. Both formulas provided similar amounts of energy (255 kcal), 36 g carbohydrate, 10 g protein, and 9 g fat per 250 ml. ONS TM DE7 formula had a significantly (p<0.05) higher viscosity (34.48±0.85 cP) than DE19 (31.98±1.11 cP). There was no significant difference in pH between the ONS TM DE7 (6.31±0.05) and DE19 (6.29±0.07). In addition, there were no significant differences in palatability between the two formulas

Enhancing antioxidant property of instant coffee by microencapsulation via spray drying

[EN] This study is aimed to improve the antioxidant property of instant coffee by using microencapsulation technique and spray drying. Concentrated coffee extract was mixed with Konjac glucomannan hydrolysate (KGMH) and Maltodextrin (MD). The mixture of coating material and coffee extract was then spray dried at 160 - 180 °C inlet air temperature and at 85-90 °C outlet air temperature. KGMH can preserve retention of phenolic compounds, DPPH scavenging activity and antioxidant activity of FRAP (p&lt;0.05 of instrant coffee better than other treatment.Sakawulan, D.; Archer, R.; Borompichaichartkul, C. (2018). Enhancing antioxidant property of instant coffee by microencapsulation via spray drying. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 643-650. https://doi.org/10.4995/IDS2018.2018.7520OCS64365

Non-destructive assessment of the oxidative stability of intact macadamia nuts during the drying process by near-infrared spectroscopy

We have developed a rapid non-destructive method to assess the oxidative stability of intact macadamia nuts using near-infrared spectroscopy (NIRS). Intact macadamia nuts of the cultivars HAES 344 ‘Kau’, HAES 660 ‘Keaau’, IAC 4–12 B, and IAC Campinas B were harvested and immediately oven-dried for 4 days at 30 °C, 2 days at 40 °C, and 1 day at 60 °C to achieve 1.5% kernel moisture content. At each drying step nuts were withdrawn and their moisture content, peroxide value (PV), and acidity index (AI) determined. The best partial least square model for PV prediction was obtained using the Savitzky-Golay (SG) second derivative resulting in a standard error of prediction (SEP) of 0.55 meq·kg−1 and a coefficient of determination (R2C) of 0.57. The best AI prediction-model result was obtained using the SG second derivative (SEP = 0.14%, R2C = 0.29). Based on the maximum quality limits of 3 meq·kg−1 for PV and 0.5% for AI, the SEP values represented 18% and 28%, respectively. Therefore, the prediction method can be considered useful since the errors are lower than the quality limits. Thus, NIRS can be used to assess the oxidative stability of intact macadamia kernels

Tapioca Resistant Maltodextrin as a Carbohydrate Source of Oral Nutrition Supplement (ONS) on Metabolic Indicators: A Clinical Trial

Tapioca resistant maltodextrin (TRM) is a novel non-viscous soluble resistant starch that can be utilized in oral nutrition supplements (ONS). This study aims to evaluate acute and long-term metabolic responses and the safe use of ONS containing TRM. This study comprised of two phases: In Phase I, a randomized-cross over control study involving 17 healthy adults was conducted to evaluate three ONS formulations: original (tapioca maltodextrin), TRM15 (15% TRM replacement), and TRM30 (30% TRM replacement). Plasma glucose, serum insulin, and subjective appetite were evaluated postprandially over 180 min. In Phase II, 22 participants consumed one serving/day of ONS for 12 weeks. Blood glucose, insulin, lipid profile, and body composition were evaluated. Gastrointestinal tolerability was evaluated in both the acute and long-term period. During phase I, TRM30 decreased in area under the curve of serum insulin by 33.12%, compared to the original formula (2320.71 &plusmn; 570.76 uIU &times; min/mL vs. 3470.12 &plusmn; 531.87 uIU &times; min/mL, p = 0.043). In Phase II, 12-week TRM30 supplementation decreased HbA1C in participants (from 5.5 &plusmn; 0.07% to 5.2 &plusmn; 0.07%, p &lt; 0.001), without any significant effect on fasting glucose, insulin, lipid profile, and body composition. The ONS was well-tolerated in both studies. TRM is therefore, a beneficial functional fiber for various food industries

Production of Konjac Glucomannan Antimicrobial Film for Extending Shelf Life of Fresh-Cut Vegetables

The aim of this research was to produce konjac glucomannan (KGM) antimicrobial film with added sweet basil oil (SB) (Ocimum basilicum) as an antimicrobial agent for inhibiting coliform bacteria which is the type most often found in fresh-cut vegetables. The concentrations of SB oil in the emulsion that inhibited the most antimicrobial growth were 4% and 6% (v/v). Film-forming conditions were evaluated by varying the volume of KGM solution per area (0.325, 0.455 and 0.585 mL·cm−2) and the concentration of SB oil (4% and 6%). After mixing the film emulsions, the emulsions were dried on a tray dryer at 50 °C for 10 h. After drying, the results showed that KGM film made at 0.325 mL·cm−2 with SB oil at 4% resulted in the smoothest surface. When the film was tested against Escherichia coli, KGM at 0.325 mL·cm−2 with 4% SB oil and at 455 mL·cm−2 with 6% SB oil produced the greatest inhibition. Film with SB oil at 4% was used to study film properties. Physical properties of the film such as tensile strength (68.08 MPa) and % elongation (33.56%) as well as water vapor transmission rate (4.44 × 10−3 g·cm−2·h−1) were determined. The KGM/SB film did not show an antimicrobial effect on packages of fresh-cut baby cos lettuce or spring onion under the experimental conditions. Further work will be carried out to study more closely the controlled release properties of KGM/SB film to enhance its antimicrobial effects. These improvements could help to develop a more successful application for its use as a natural biopreservative in minimally-processed products like fresh-cut vegetables

Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) studies of corn at subzero temperatures

The physical states of water and its freezing behaviour in shelled corn during subzero drying were determined by using ²H NMR and ¹H MRI techniques. In this context, the ²H NMR spin–lattice relaxation times (T₁) and spin–spin relaxation times (T₂) of water in corn were measured. The relaxation times were found to decrease with decreasing temperature. The results revealed that there were two main water components in corn of >30% wb (wet basis) with long and short T₁. Both components exhibited minima around −20 °C. In more dehydrated corn (18.6% wb) only a single water component, with short T₁ and T₂ was observed. ¹H MRI images revealed the location of water and its freezing behaviour in different areas