Characterization of Biodegradable Films Made from Taro Peel (Colocasia esculenta) Starch.

Studies of renewable polymers have highlighted starch's role to replace petroleum-based components to produce biodegradable films with plastic-like qualities. In this study, the novelty of taro peel starch (TPS) to produce such films using the casting technique is reported for the first time. A response surface method (RSM) approach was employed to optimize different concentrations of TPS (2.5−3.5%, w/w) and glycerol (25−35%, w/w) and investigate their effects on the physico-mechanical and water barrier properties of TPS films. TPS films showed a positive linear effect (p < 0.05) for thickness (0.058−0.088 mm), opacity (1.95−2.67), water vapor permeability (0.06−0.09 g∙m/m2∙kPa∙h), and cubic effect (p < 0.05) for moisture content (0.58−1.57%), which were linked to high starch concentrations when plasticized with glycerol. X-ray diffraction analysis of TPS films depicted "amorphous"-type crystalline structure peaks at 19.88°, while the thermogravimetric analysis of the film samples exhibited 75−80% of the weight loss of TPS film in the second phase between temperatures of 300 °C to 400 °C. All films exhibited homogenous, transparent surfaces with flexibility, and completely degraded in 5 days in simulated river water and composting soil environments, which confirmed TPS as a promising film polymer in food packaging.

A Comprehensive Characterization of Biodegradable Edible Films Based on Potato Peel Starch Plasticized with Glycerol.

Potatoes are a source of starch, which is an eco-friendly alternative to petrochemicals in plastic production. Increasing potato production also creates agricultural waste that could be converted to potato peel starch (PPS) and developed as films. A response surface method approach was employed to optimize the bioconversion of PPS (2, 4, and 6% w/v) and compared with carboxymethyl cellulose (CMC)-based films. The microstructure analysis of PPSF showed increased thickness, decreased swelling power, water solubility, and vapor permeability, which were linked to increased molecular interactions as a function of PPS increments. However, low-starch PPSF exhibited high transparency, good mechanical properties, and thermal stability (high melting temperature), pliability, and accelerated seawater and soil biodegradation (~90%: 20 and 50 days, respectively). All films exhibited thermal stability at >100 °C and retained similar amorphous characteristics, evidenced by their flexibility, which confirmed the potential use for PPS in packaging perishable and cooled foods.

Development of halochromic indicator film based on arrowroot starch/iota-carrageenan using Kyoho skin extract to monitor shrimp freshness.

Increasing trends in food safety awareness drive consumer demands for fresher healthier diets and has led to the development of low-cost pH-sensitive indicator films to evaluate deterioration levels in fresh foods. Arrowroot starch/iota-carrageenan-based films were combined with 10, 30, 50% Kyoho skin extract (KSE) to produce indicator films with halochromic abilities. The KSE indicator films were characterized based on their physico-mechanical, functional, and crystallinity properties; thermal stability; and their pH-dependent color changes in in situ anthocyanin-based monitoring of shrimp freshness. All KSE indicator films displayed compact structure under scanning electron microscope analysis and increased tensile strength, exhibited UV-vis barrier ability, and presented low water wettability. Moreover, FTIR signaled strong hydrogen bond interactions among polymers and KSE that strengthened peak crystallinity in XRD analysis and lowered weight loss at melting temperature, which indicated thermal stability of the indicator films. Furthermore, pH-sensitivity of the indicator films integrated with natural KSE anthocyanin demonstrated color changes from purple to red under acidic conditions, purple to green in an ammonium environment, and yellow appeared in high alkaline conditions. Finally, this study demonstrated the food packaging and halochromic capacity of biopolymer-based pH-sensitivity of the KSE indicator films in real-time monitoring of shrimp at room storage temperatures.

Characterization of a natural biodegradable edible film obtained from arrowroot starch and iota-carrageenan and application in food packaging.

Future food packaging trends are shifting to natural and eco-friendly materials developed from biopolymers such as starch and other hydrocolloids, to reduce pollution from synthetic polymers. Arrowroot starch (AS) (3.5, 3, 2.5, and 2%) and iota-carrageenan (IC) (0.5, 1, 1.5, and 2%) were blended to develop biodegradable edible films (AS/IC-BEF), which were compared against AS-BEF (4%, control). All films were characterized based on their physico-mechanical and barrier properties, functional group properties, crystallinity properties, thermal properties, and soil and seawater biodegradation. AS-BEF exhibited smooth surface, high transparency, and completed composting soil biodegradation in 7 days whereas AS/IC-BEF samples exhibited higher tensile strength, water solubility, swelling properties, and barrier properties, but completed biodegradation after 30 days. XRD analysis indicated IC fractions contributed to increase in degree of crystallinity (28.35°) and FTIR signaled strong hydrogen bond interactions between polymers. AS/IC-BEF samples demonstrated melting temperatures between 158 and 190 °C while glass transition temperatures ranged from 153 to 176 °C, which resulted in maximum weight loss around 50-55% at melting temperatures. Finally, AS/IC-BEF samples successfully inhibited weight loss of cherry tomatoes at room temperature and extended their shelf life to 10 days, which indicated that the AS/IC composite material produced a BEF with potential food and industrial applications.

Twenty-six years anniversary (1992-2018) of Food Research International: An overview of research trends.

Food Research International, the peer-reviewed international journal launched in 1992, celebrated its 26 years anniversary in 2018. Therefore, we presented an overview on the trending profile of Food Research International and its scientific achievements from 1992 to 2018 by identifying its trends in impact factor, h-index, journal rank, most cited articles, institutes, and countries. The data were retrieved from the Web of Science Core Collection and Scopus®. Several scientific achievements were observed in publications (a total of 6,751), impact factor (0.63-3.57), and citations (a total of 1,78,770) over the 26-year period. The most cited documents were related to the interdisciplinary research within food science and technology and contributed to strengthen the progress of science within the field. In 2007, a systematic review published in Food Research International explored the understanding of microencapsulation and their applications, which captured the scientific attention on microencapsulation in global research community. The journal published in vitro antioxidant assays that highly contributed to the process and analytical applications in food processing industries. Food Research International reported a good citing (cites given) and cited (cites received) relationship with the leading journals within the field. Brazil (301) was the most productive country with the highest contributions to the journal. Overall, these findings highlighted the evolution, quality, and productivity of the journal and provided an opportunity for early-career researchers to conduct more innovative studies in food science and publish in Food Research International.

Functional Activity of Four Autochthonous Strains L. paraplantarum AB362736.1, L. plantarum MF369875.1, W. paramesenteroides CP023501.1, and E. faecalis HQ802261.1 in a Probiotic Grape Marmalade during Storage.

Grape foods with probiotics are sources of beneficial bacteria for the gastrointestinal (GI) tract and also have a high antioxidant capacity. The addition of probiotics to dairy food is a traditional process; therefore, probiotic non-dairy products might contribute to a daily antioxidant diet to improve consumer life quality and health. This research was undertaken to develop a grape marmalade with a probiotic base to investigate the potential antioxidant activity in the probiotic non-dairy product. Thus, changes in active culture numbers, pH level, glucose concentration, and antioxidant properties were evaluated. Most of the isolates demonstrated higher growth in the grape marmalade than the synthetic grape marmalade, which was greater than 7 log colony-forming units (CFU)/g within 90 days of storage at 4 °C. In addition, most of the wild isolates grew beyond the critical count of 106 CFU/g in sampling between 60 and 90 days of storage. Moreover, probiotic grape marmalade with probiotics showed a strong antioxidant capacity that failed to differ significantly with the synthetic medium. The study confirmed Lactobacillus paraplantarum AB362736.1, Lactobacillus plantarum MF369875.1, Weissella paramesenteroides CP023501.1, and Enterococcus faecalis HQ802261.1 were ideal bacteria for the probiotic process of grape marmalade.

Viability of 4 Probiotic Bacteria Microencapsulated with Arrowroot Starch in the Simulated Gastrointestinal Tract (GIT) and Yoghurt.

Probiotic bacteria are usually encapsulated to increase their survival through passage of the simulated gastrointestinal tract (GIT). Four Lactobacilli were freeze-dried and encapsulated with maltodextrin (maltodextrin 1.25 g, whey 0.25 g, bacteria 0.5 g, and water 2 mL) and arrowroot starch (arrowroot 1.25 g, whey 0.25 g, bacteria 0.5 g, and water 2 mL). The effects of different coatings were evaluated for their viability in the GIT and yogurt. The findings indicated no significant differences at p > 0.05 in the survival of the encapsulated cells with increased concentrations of arrowroot and maltodextrin. The viability of the encapsulated bacteria was increased in the simulated GIT with high counts of 109 cfu/mL after 30 min stiffening in 1 µm size beads. However, the bead fermented yogurt exhibited insignificant difference on the survivability of the organisms in a simulated GIT after 15 days. Lactobacillus plantarum, Weissela paramesenteroides, Enterococcus faecalis, and Lactobacillus paraplantarum showed a significant increase of viable cells at p > 0.05 after freeze-drying in comparison with free cells at high bile salt concentrations and low acidity. This study confirmed that arrowroot starch and maltodextrin combinations in encapsulation might be an effective method that could allow viable probiotic bacteria to reach the large intestine.

Application of chemometric techniques: An innovative approach to discriminate two seaweed cultivars by physico-functional properties.

Chemometric techniques were employed to discriminate two Indonesian seaweed cultivars (Kappaphycus alvarezii and Sargassum duplicatum) based on their physico-functional properties. Data of physico-functional properties, including emulsifying activity and bulk density, were processed using multivariate, discriminant analysis (DA), principal component analysis (PCA), and cluster analysis (CA). Significant differences (p < 0.05) and discrimination (multivariate analysis (F9,14 = 57.85; Wilks's lambda = 0.02, p < 0.0001)) were determined among physico-functional properties of seaweed powders. In addition, DA method clarified (Λ = 0.02 and χ2 = 63.74) variations between samples along with two discriminate functions. Moreover, PCA (49.63% with Eigenvalues > 1) and CA (clusters 1 and 2) methods confirmed that the seaweed samples possessed differing physico-functional properties, which implied their distinctive use in food product development. Overall, our results demonstrated strong variation in seaweed powers using chemometrics, which might contribute to the rapid applicability of chemometrics in evaluating novel food material.

Statistical comparative study between the conventional DPPH spectrophotometric and dropping DPPH analytical method without spectrophotometer: Evaluation for the advancement of antioxidant activity analysis.

Recently, new approaches for measuring antioxidant activity have been developed to eliminate or reduce the use of a spectrophotometer. All analytical methods must provide consistent and reliable results, which should be compared with statistical models. Therefore, we compared the conventional and dropping DPPH methods with three widely used standards. We employed and compared with three statistical methods. Good R-squared (R2 = ≥0.96) confirmed the similarity in comparison of using dropping DPPH method compared with the conventional DPPH method and reported lower deviations (ARD = -0.32 to 0.13; RMSD = 0.10 to 1.15). Bland-Altman method (95% CI) demonstrated a good agreement between the two methods using standards and grape extracts (skin and seed). These findings suggested that the dropping DPPH method proved cheaper (without spectrophotometer) and correlated well with the conventional DPPH method. Therefore, this method could be affordably conducted in research laboratories in developing and less developed countries.

In vitro antioxidant activity of Kyoho grape extracts in DPPH and ABTS assays: Estimation methods for EC50 using advanced statistical programs.

The antioxidant capacities of Kyoho skin, seed, and flesh extracts were determined using DPPH and ABTS assays and a suitable statistical program was tested for the prediction of EC50 values of Kyoho skin, seed, and flesh extracts obtained by DPPH and ABTS assays. Statistical programs: OriginPro® version 8, GraphPad Prism® version 7, GraphPad Prism® version 7 five-parameter (5P) logistic model, SigmaPlot® version 14.0, Microsoft Excel® version 2016, interpolation log, and direct interpolation methods were employed to estimate the EC50 values. Linear regression and direct interpolation results showed deviations for non-linear models in the prediction of EC50 values of grape extracts. The correlation results of grape flesh extracts demonstrated a positive correlation (r = ≥ 0.95) between EC50 values of antioxidant assays. Therefore, non-linear methods were appropriate for EC50 calculations. These findings have significant implications for selecting an efficient statistical tool to calculate EC50 values for DPPH and ABTS assays.

Antioxidant effects of 14 Chinese traditional medicinal herbs against human low-density lipoprotein oxidation.

The relationship between the antioxidant activities and inhibitory effect of 14 Chinese medicinal herbs against oxidized low-density lipoprotein (LDL) formation was evaluated. Prolongation of the lag phase of LDL oxidation depended on the concentration of the herbs. The concentration of each herb that was able to prolong the lag time by about two-fold was calculated and expressed as doubling-time concentration. The lower the doubling-time concentration, the stronger the inhibitory effect exhibited toward LDL oxidation. Among them, Chrysanthemi Flos (Chrysanthemum morifolium ramat; gan jú hua), Crataegi Fructus (Crataegus pinnatifida Bge. var. major N.E.Br.; shan zha), and Roselle (Hibiscus sabdariffa Linn.; luò shén) showed significant inhibitory effects. Correlation coefficients between doubling-time concentration and radical-scavenging activities were high; the total phenolic content was also high. In conclusion, phenolic compounds contributed not only to antioxidant activities, but also to the inhibitory effect against LDL oxidation. Chrysanthemi Flos, Crataegi Fructus, and H. sabdariffa, with lower doubling-time concentrations, could be potent phytochemical agents to reduce LDL oxidation and prevent the progression of atherosclerosis.

The role of polyphenol oxidase and peroxidase in the browning of water caltrop pericarp during heat treatment.

The mechanism of browning involving enzymatic browning was investigated in the pericarp of water caltrop, an Asian vegetable popular for its taste and medicinal properties. Polyphenol oxidase (PPO) and peroxidase (POD) activities were determined in pericarp at various times and temperatures. Water caltrop consisted of 44.22% moisture content, 37.23% crude fibre, and 2.63% crude protein. PPO and POD activities dropped from 62 and 38units/g sample, respectively, as water temperature was increased from 30 to 80°C. Optimum pH and temperature for PPO activity was at pH 5.0, 25-45°C, and POD activity peaked at 60°C. High PPO and POD activities at 40-50°C resulted in degradation of phenolic compounds, which led to increased aggregation of browning pigments and discolouration (lower L-values) of the pericarp. Enzymatic browning was determined as the major factor in the browning discolouration of heat-treated water caltrop pericarp.

Resveratrol inhibits human lung adenocarcinoma cell metastasis by suppressing heme oxygenase 1-mediated nuclear factor-kappaB pathway and subsequently downregulating expression of matrix metalloproteinases.

Resveratrol exhibits potential anti-carcinogenic activities. Heme oxygenase-1 (HO-1) is involved in angiogenesis and tumor metastasis. Matrix metalloproteinases (MMPs) are key enzymes in the degradation of extracellular matrix, and their expression may be dysregulated in lung cancer metastasis. In this study, we investigated the anti-invasive mechanism of resveratrol in lung cancer cells. HO-1 was shown to be elevated (approximately 4.7-fold) in lung cancer tumor samples as compared with matched normal tissues. After treatment of lung adenocarcinoma cell line A549 cells with resveratrol (50 microM) for 24 h, the migratory and invasive abilities (38 and 30% inhibition, respectively) of A549 cells were significantly reduced. Resveratrol significantly inhibited HO-1-mediated MMP-9 (35% inhibition) and MMP-2 (28% inhibition) expression in lung cancer cells. Nuclear factor (NF)-kappaB inhibitor induced a marked reduction in MMP-9 and MMP-2 expression, suggesting NF-kappaB pathway could play an important role. Furthermore, HO-1 inhibition and silencing significantly suppressed MMPs and invasion of lung cancer cells. Our results suggest that resveratrol inhibited HO-1 and subsequently MMP-9 and MMP-2 expression in lung cancer cells. The inhibitory effects of resveratrol on MMP expression and invasion of lung cancer cells are, in part, associated with the HO-1-mediated NF-kappaB pathway.

A novel bread making process using salt-stressed Baker's yeast.

By adjusting the mixing order of ingredients in traditional formula, an innovative bread making process was developed. The effect of salt-stressed Baker's yeast on bread dough of different sugar levels was investigated. Baker's yeast was stressed in 7% salt solution then mixed into dough, which was then evaluated for fermentation time, dough fermentation producing gas, dough expansion, bread specific volumes, and sensory and physical properties. The results of this study indicated that salt-stressed Baker's yeast shortened fermentation time in 16% and 24% sugar dough. Forty minutes of salt stress produced significant amount of gas and increased bread specific volumes. The bread was softer and significantly improved sensory properties for aroma, taste, and overall acceptability were obtained.

Studies on the expression of liver detoxifying enzymes in rats fed seaweed (Monostroma nitidum).

The expression level of phase I (CYP1A1 and CYP1A2) and phase II (GST, and UGT) enzyme-coded genes were measured in liver microsomes of 30 Sprague-Dawley rats fed sea weed (Monostroma nitidum). Quantitative and qualitative analysis of the detoxifying enzymes were investigated using reverse transcription polymerase reaction (RT-PCR) and real time polymerase reaction (Real-time PCR) techniques. The antioxidative properties of seaweed were screened and investigated for its hepatoprotective activity in rat. There was no significant induction of GSTYa1, GSTYa2, and CYP1A2. However, an M. nitidum diet was found to significantly increase UGT1A1 and UGT1A6 mRNA levels and to decrease CYP1A1 mRNA levels in rat liver. Structural studies confirmed the presence of sulfated polysaccharides in the seaweed samples. The results demonstrate the potential of seaweed as a natural source of sulfated polysaccharide substances with potential use in chemoprevention medicine.

Physical investigations of surface membrane-water relationship of intact and gelatinized wheat-starch systems.

Water mobility in intact and dried gelatinized starch was investigated by gravimetric water sorption, scanning electron microscopy (SEM), and solid-state nuclear magnetic resonance (NMR). A multi-component exponential model quantitatively measured different spin-spin relaxation times of two water components, namely bound water (Tsi) at 3.16 ms and mobile or free water (Tsii) at 3.23 ms, as a function of water activity (aw). The starch samples were moistened to 30% moisture content. SEM confirmed the disrupted, absorbent microstructure in dried, gelatinized starch powder and revealed starch granules in an incomplete gelatinized state, as compared to the complete membrane surface of the intact starch granule. Starch granules sorbed significantly differently at low aw, but after aw=0.44, sorption leveled similarly with increasing aw. The presence and role of a surface membrane was concluded, in support of the hypothetical "water sink" properties of intact granules, and was considered to influence in part the sorption behavior of incompletely gelatinized starch granules.