Thermal and pH degradation kinetics of anthocyanins in natural food colorant prepared from black rice bran

In situ growth of curcumin-loaded cellulose composite film for real-time monitoring of food freshness in smart packaging

Visual pH-responsive packaging material is particularly important in food supply chain safety monitoring due to their non-destructive monitoring method and intuitive result. However, it has always been limited by the instability performance of pH-response components and carriers, which further hinders its wide food safety application. To address these challenges, we selected cellulose with remarkable biocompatibility and mechanical properties as the carrier, and high pH-responsive curcumin to develop a smart packaging material (RC/GC composite film) with real-time food safety monitoring. Compared with pure cellulose film, the RC/GC composite film exhibited excellent mechanical properties (4-fold enhancement) and thermal stability (100 °C increasing). Meanwhile, based on the first reported strategy of curcumin in-situ growth during cellulose film formation, the RC/GC composite film exhibited exceptional antioxidant activity (89.2 %), antimicrobial property (91.6 %), and significant pH-responsive sensitivity (within 15 s). This innovative approach offers a new strategy for easy-to-use and effective monitoring of food spoilage in packaging materials.

Intelligent double-layer film based on gellan gum/modified anthocyanin/curcumin/sodium alginate/zinc oxide for monitoring shrimp freshness

In this study, intelligent double-layer films were prepared using modified black rice anthocyanin (MBRA)-curcumin (CUR)-gellan gum (GG) as the inner indicator layer and sodium alginate (ALG)‑zinc oxide (ZnO) as the outer antimicrobial layer. The bilayer films were successfully prepared, as revealed by scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction measurements. The mechanical characteristics, moisture content, and water vapor resistance of GG-MBRA/CUR1@ALG-ZnO, GG-MBRA/CUR2@ALG-ZnO, and GG-MBRA/CUR3@ALG-ZnO films showed significant enhancement compared to GG-MBRA/CUR3 and ALG-ZnO films. The bilayer films exhibited excellent pH responsiveness and reacted effectively to ammonia. The outer layer significantly improved the antioxidant and antibacterial properties of the inner layer. When the films were applied to shrimp, it was found that the double-layer films not only monitored the freshness of the shrimp in real-time but also were influential in extending the shelf life of the shrimp by about 1 d. Therefore, the double-layer film demonstrated potential as a smart packaging material for real-time monitoring of meat product freshness.

Valorization of cashew nut testa phenolics through nano-complexes stabilized with whey protein isolate and β-cyclodextrin: Characterization, anti-oxidant activity, stability and in vitro release

Cashew nut testa (CNT) is an underutilized cashew by-product rich in polyphenols. The applications of CNT are limited due to its astringency, less solubility, and instability of polyphenols during the processing. Nanoencapsulation was used to overcome these limitations. β-cyclodextrin alone and in combination with whey protein isolate (WPI) was used for nano-complex preparation. The WPI/CD-CNT nano-complex powder showed higher encapsulation efficiency (86.9%) and yield (70.5-80%) compared to CD-CNT powder. Both the spray-dried powders showed improved thermal stability, higher solubility (97%), less moisture content, and increased DPPH and ABTS radical scavenging activities indicating potential food and agricultural applications. In addition, the nano-complex powders showed a controlled release of core bio-actives under gastric and intestinal pH compared to the non-encapsulated CNT phenolic extract. Degradation kinetics studies of the CNT extract after thermal and light treatments were also discussed. Both the nano-complexes showed high stability under light and thermal treatment. The results suggest that valorization of CNT can be done through nano-complex preparation and WPI and β-CD are efficient carrier materials for the encapsulation of polyphenols with potential applications in food and agriculture.

Anthocyanin-Loaded Polymers as Promising Nature-Based, Responsive, and Bioactive Materials

Anthocyanins are a specific group of molecules found in nature that have recently received increasing attention due to their interesting biological and colorimetric properties that have been successfully applied in several fields such as food preservation and biomedicine. Consequently, reviews devoted to a general overview of these flavonoids have proliferated in recent years. Meanwhile, the incorporation of anthocyanins into polymeric systems has become an interesting strategy to widen the applicability of these molecules and develop new smart and functional polymers in the above cited areas. However, anthocyanin-based polymers have been scarcely reviewed in the literature. Accordingly, this review aims to be a systematic summary of the most recent approaches for the incorporation of anthocyanins into macro-, micro-, or nanostructured polymers. Moreover, this work describes the fundamentals of the applicability of smart anthocyanin-based polymers and offers an updated review of their most interesting applications as sensors, biological regulators, and active materials.

Anthocyanins-natural pigment of colored rice bran: Composition and biological activities

Rice by-products are a potential source of various bioactive substances with great processing potential, which are receiving increasing attention. Among them, rice bran is a by-product of rice milling, with high nutritional value and health benefits. Colored rice bran contains a large amount of anthocyanins responsible for color and bioactivities. And anthocyanins are often added to foods as a natural pigment, serving to enhance both the visual appeal and nutritional value. Recent advances in the composition and bioactivities of four common colored rice bran anthocyanins (black, purple, red, and purple red rice) are reviewed in this paper. Rice bran anthocyanins have been confirmed to exhibit biological potential for human health, with their main biological activities being antioxidant, anti-atherosclerosis, anti-cancer, neuroprotective, retinoprotective, immunomodulatory, anti-aging and anti-obesity effects. The structure of anthocyanins determines their biological activities. The anthocyanins composition of rice bran with different colors varied greatly, while that of rice bran with the same color is also slightly different, which is attributed to the rice varieties, growing environment and cropping conditions. However, it remains necessary to conduct further clinical studies to support the health activities of anthocyanins. The present review provides information value for the further development and comprehensive utilization of rice bran anthocyanins.

Precursor-directed production of water-soluble red Monascus pigments with high thermal stability via azaphilic addition reaction-based semi-synthesis

Red Monascus pigments (MPs) are a large group of polyketides from the fungus Monascus which have been widely used as food colorants. In this study, a variety of red MPs congeners were prepared to explore promising water-soluble candidates for application in liquid food formulations. The results showed that by combining the two-stage, low-pH fermentation strategy with a downstream purification step of fractional crystallization, precursors of red MPs, namely monascorubrin and rubropunctatin, were obtained with a purity of 91.9%. Then, via the azaphilic addition reaction, 18 types of red MPs congeners carrying different amino acid moieties (MPs-aa) were semi-synthesized. Compared to rubropunctamine and monascorubramine, the water solubility, pH and thermal stability of MPs-aa were improved greatly. MPs-His, MPs-Phe, MPs-Tyr and MPs-Trp were identified to be the most resistant to pasteurization. These findings provide water-soluble red MPs candidates with high thermal stability and an attractive approach for their large scale production.

Anthocyanin Profiles in Colored Potato Tubers at Different Altitudes by HPLC-MS Analysis with Optimized Ultrasound-Assisted Extraction

The elevated anthocyanin content of colored potatoes produces numerous health benefits in humans. However, there is a paucity of studies exploring the influence of environmental factors on anthocyanin components in colored potatoes. In our work, the Box-Behnken design was adopted to optimize anthocyanin extraction from colored potato tubers with ultrasound assistance. The response surface model was stable and reliable (R2 = 0.9775), and under optimal extraction conditions, namely an ultrasonic power of 299 W, an extraction time of 10 min, and a solid-liquid ratio of 1:30 (g/mL), the yield reached 4.33 mg/g. Furthermore, the anthocyanins of colored potato tubers grown at different altitudes were determined by high-performance liquid chromatography-mass spectrometry with optimized ultrasound-assisted extraction, the results showed that anthocyanin levels were the highest at high altitudes, whereas anthocyanins were almost undetectable at mid-altitude. Moreover, the types of anthocyanin compounds present in colored potatoes varied at different altitudes. The red clones exhibited substantial accumulation of pelargonidin across all three altitudes. In contrast, the main anthocyanins found in purple clones were malvidin, petunidin, and cyanidin. We identified the anthocyanin components with a strong correlation to the environment, thereby establishing a fundamental basis for the breeding of potato clones with high anthocyanin content.

Effect of Bioactive Compounds from Pumpkin Powder on the Quality and Textural Properties of Shortbread Cookies

The problem of food with functional ingredients, characterized by low energy intake and a variety of phytonutrients with biological activity, is one of the concerns of the population. The objectives of this study were to investigate the effect of pumpkin powder and its bioactive components on the quality, color and textural properties of shortbread cookies. In the drying process of pumpkin powder (Cucurbita moschata) at 60 ± 2 °C, the physicochemical parameters did not change significantly in relation to fresh pulp. The chromatic parameters L*, a* and b* showed that the pumpkin powder was brighter than the pulp, with a greater presence of yellow pigments. Pumpkin powder presented a rich source of bioactive compounds (polyphenols flavonoids, carotenoids) with an antioxidant potential of 161.52 mmol TE/100 g DW and 558.71 mg GAE/100 g DW. Antimicrobial activity against Gram-positive (Staphylococcus aureus, Bacillus cereus), Gram-negative (Escherichia coli, Salmonella Abony and Pseudomonas aeruginosa) bacteria and high antifungal activity against Candida albicans were attested. The sensory, physicochemical, texture parameters and color indicators of shortbread cookies with yellow pumpkin powder (YPP) added in a proportion of 5-20% were analyzed. The optimal score was given to the sample of 15% YPP. The use of 15-20% YPP contributed to improved consistency due to the formation of complexes between starch and protein.

Lemon juice improved color acceptance of aronia (Aronia melanocarpa) pound cake by copigmentation

Anthocyanins can be changed into dark purplish color during pound cake preparation due to high temperature and alkaline baking soda, which lowers color acceptance by consumers. To stabilize a red color of anthocyanins in pound cake enriched with aronia (Aronia melanocarpa) powder, lemon juice was added to contain final concentrations of 0, 1, 2, and 3% (w/w) in the pound cake, which were assigned as control, PL1%, PL2%, and PL3%, respectively. As lemon juice amount increased, redness (a*) and sensory color perception as well as overall acceptance were enhanced, whereas hardness, gumminess, and chewiness decreased in texture profile analysis. In a model system, the addition of lemon juice to aronia solution caused bathochromic shift and hyperchromic effect in UV-Vis absorption spectrum, which are typical phenomena of copigmentation derived from interactions between anthocyanins and copigments. The results indicate that lemon juice improved color acceptance for aronia pound cake by copigmentation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01286-1.

Proanthocyanins and anthocyanins in chestnut (Castanea mollissima) shell extracts: biotransformation in the simulated gastrointestinal model and interaction with gut microbiota in vitro

BACKGROUND

Chestnut (Castanea mollissima) shell is rich in flavonoids and our previous studies showed that proanthocyanins and anthocyanins were the two markedly varied flavonoids in chestnut shell extracts (CSE) during digestion. Here, the biotransformation of proanthocyanins and anthocyanins in a simulated gastrointestinal model, and the interactions between non-absorption CSE (NACSE) and gut microbiota in vitro, were investigated by ultra-high-performance liquid chromatography combined with triple-quadrupole mass spectrometry and 16S rRNA sequencing.

RESULTS

Chestnut shell was richer in proanthocyanins and anthocyanins, while the loss of proanthocyanins was greater after digestion. Additionally, the content of anthocyanin decreased after gastric digestion but increased after intestinal digestion and remained stable after fermentation. After fermentation, delphinidin-3-O-sambubioside and pelargonidin-3-O-galactoside were newly formed. Furthermore, microbiome profiling indicated that NACSE promoted the proliferation of beneficial bacteria, while inhibiting pathogenic bacteria.

CONCLUSION

All these data suggest that CSE may be a promising candidate to protect gut health. © 2023 Society of Chemical Industry.

Valorization of Peels of Eight Peach Varieties: GC-MS Profile, Free and Bound Phenolics and Corresponding Biological Activities

Sustainability, becoming essential for food processing and technology, sets goals for the characterization of resources considered as food waste. In this work, information about the GC-MS metabolites of peach peels was provided as a tool that can shed more light on the studied biological activities. In addition, distribution patterns and contribution of the chemical profile and free and bound phenolic compounds as antioxidant, antimicrobial, and enzymatic clusters in peach peels of different varieties of Bulgarian origin were studied. The two applied techniques (alkaline and acid hydrolysis) for releasing the bound phenolics reveal that alkaline hydrolysis is a better extraction approach. Still, the results indicate the prevalence of the free phenolics in the studied peach peel varieties. Total phenolics of peach wastes were positively correlated with their antioxidant activity. The antioxidant activity results certainly defined the need of an individual interpretation for each variety, but the free phenolics fractions could be outlined with the strongest potential. The limited ability of the peels' extracts to inhibit α-amylase and acetylcholinesterase, and the moderate antimicrobial activity, on the other hand, indicate that the potential of peach peels is still sufficient to seek ways to valorize this waste. Indeed, this new information about peach peels can be used to characterize peach fruits from different countries and/or different food processes, as well as to promote the use of this fruit waste in food preparation.

Thermal and pH stability of Justicia spicigera (Mexican honeysuckle) pigments: Application of mathematical probabilistic models to predict pigments stability

Kinetic and probabilistic (Time-to-Failure, TTF) models were used to predict the color (L*, a*, b* total color differences (ΔE), Hue and Chroma) stability of Justicia spicigera leaves pigments subjected to different temperatures (40 - 80 °C) and pHs (2 - 12). The change in pH caused different hues (from 60° = orange red to 268° = deep-blue) due to the shift effect of anthocyanins in the extract. Temperatures higher than 60 °C increased the color degradation. High heat sensitivity was observed at pH 4 (Ea = 90.27) and 10 (Ea = 154.99 kJ/mol). The Time-to-Failure model for both ΔE and Hue describes the effect of pH and temperature in the J. spicigera extracts. High pHs and temperatures applied to the extracts increased the probability of showing ΔEs > 4 or Hue changes over 20 %. Nearby the neutral region of pH, pigments of J. spicigera were more stable. The TTF model might be a useful tool to describe and predict the behavior of pigments added to foods.

Addition of Chelators Increased the Stability of Black Rice Anthocyanins against the Metallic Ions in Tap Water and Improved the Coloration of Steamed Cold Noodles

The anthocyanins in black rice extract (BRA) are sensitive to metallic ions, which restrict its application in the coloration of steamed cold noodles in China that uses tap water as the solvent. Food-grade chelators were added to check if they could increase the stability of BRA. The results indicated that the color decay of BRA in tap water was mainly caused by Fe3+, Cu2+, and Fe2+, and the addition of chelators could effectively antagonize this effect. Coloration with the BRA solution containing the optimized chelator formulation of 0.01% ethylenediaminetetraacetic acid disodium, 0.08% sodium hexametaphosphate, and 0.064% sodium tartrate conferred comparable appearance and chromatic attributes with those of the noodle colored by deionized water-dissolved BRA. The steamed cold noodles colored by the chelators-containing BRA exhibited increased springiness and decreased starch retrogradation, and possessed potential health functions due to its slightly increased resistant starch content and markedly enhanced antioxidant capacity. Hence, the addition of chelators is a feasible way to increase the color stability of BRA in tap water, and the chelators-supplemented BRA could be used to produce steamed cold noodles with attractive color and health benefits.

Photochemistry, Functional Properties, Food Applications, and Health Prospective of Black Rice

This review investigates black rice’s photochemistry, functional properties, food applications, and health prospects. There are different varieties of black rice available in the world. The origins of this product can be traced back to Asian countries. This rice is also known as prohibited rice, emperor’s rice, and royal’s rice. Black rice is composed of different nutrients including fiber, protein, carbohydrates, potassium, and vitamin B complex. It contains an antioxidant called anthocyanin and tocopherols. Antioxidants are found mostly in foods that are black or dark purple. Due to its nutritious density, high fiber level, and high antioxidant content, black rice is a good alternative to white and brown rice. Utilizing black rice in various foods can enhance the nutritional value of food and be transformed into functional food items. Many noncommunicable diseases (NCDs) can be prevented by eating black rice daily, including cancer cells, atherosclerosis, hypertension, diabetes, osteoporosis, asthma, digestive health, and stroke risk. This review aim was to discuss the role of nutritional and functional properties of black rice in the formation of functional food against different noncommunicable diseases.

Thermal stability enhancement of berry anthocyanins by co-pigmentation with extracts from natural sources

The suitability of mandarin (MP), orange (OP) and pomegranate peel powders (PP) for co-pigmentation of dewberry, viburnum, red hawthorn, black hawthorn, and barberry anthocyanins was investigated. Spectrophotometric measurements indicated co-pigmentation causing both a hyperchromic effect (ΔABSmax = 5–13) and bathochromic shift (Δλ vis-max up to 13 nm). The degradation kinetics of anthocyanins were estimated at temperatures ranging from 70 to 90 °C. First-order reactions with rate constants of 0.45–2.93 min−1 and 0.30–2.00 min−1 were observed for the reference and PP co-pigmented samples, respectively. The t 1/2 values were 3.90–25.7 h for the reference and 5.8–38.5 h for the co-pigmented samples. The activation energy (E a) values were higher in co-pigmented samples (49.16–77.77 kJ/mol) than in reference samples (41.82–68.75 kJ/mol), except for black hawthorn, which had a lower E a value in the co-pigmented sample. The thermodynamic parameters (enthalpy, free energy, and entropy) evaluated indicated a positive effect of co-pigmentation on the thermal treatment of anthocyanins.

The effects of β-lactoglobulin on cyanidin-3-O-glucoside antioxidant activity and bioaccessibility after heat treatment

The impact of heat treatment at different temperatures on the interaction of β-lactoglobulin (β-Lg) and anthocyanin-3-O-glucoside (C3G) was studied. Heat treatment and the addition of C3G changed the secondary structure of β-Lg with decreasing β-sheets and increasing random coils. Interactions between C3G and β-Lg were mainly via hydrogen bonds and van der Waals forces at 25 °C. The elevated temperature promoted hydrophobic interactions between C3G and β-Lg due to an increase in the hydrophobic groups and amino groups on the surface of β-Lg molecules. The addition of β-Lg to the C3G eliminated heat-induced thermal degradation of C3G. The β-Lg-C3G interactions accompanied with increased particle size and constant zeta potential could increase the antioxidant capacity of C3G approximately by 4% to 10% and protect the colour of C3G from degradation under heat treatment. The C3G bioaccessibility with β-Lg addition increased by 26.08%, 33.45%, 83.09%, 72.27%, and 354.62% compared with C-25, C-60, C-85, C-100, and C-121, respectively. The protective effect of the non-covalent interactions on C3G at high temperatures (85 °C to 121 °C) was significantly stronger than at 25 °C and 60 °C. The application of β-Lg in foodstuffs could enhance the antioxidant activity and bioaccessibility of C3G.

Complexation of Anthocyanin-Bound Blackcurrant Pectin and Whey Protein: Effect of pH and Heat Treatment

A complexation study between blackcurrant pectin (BCP) and whey protein (WP) was carried out to investigate the impact of bound anthocyanins on pectin−protein interactions. The effects of pH (3.5 and 4.5), heating (85 °C, 15 min), and heating sequence (mixed-heated or heated-mixed) were studied. The pH influenced the color, turbidity, particle size, and zeta-potential of the mixtures, but its impact was mainly significant when heating was introduced. Heating increased the amount of BCP in the complexes—especially at pH 3.5, where 88% w/w of the initial pectin was found in the sedimented (insoluble) fraction. Based on phase-separation measurements, the mixed-heated system at pH 4.5 displayed greater stability than at pH 3.5. Heating sequence was essential in preventing destabilization of the systems; mixing of components before heating produced a more stable system with small complexes (<300 nm) and relatively low polydispersity. However, heating WP before mixing with BCP prompted protein aggregation—producing large complexes (>400 nm) and worsening the destabilization. Peak shifts and emergence (800−1200 cm−1) in infrared spectra confirmed that BCP and WP functional groups were altered after mixing and heating via electrostatic, hydrophobic, and hydrogen bonding interactions. This study demonstrated that appropriate processing conditions can positively impact anthocyanin-bound pectin−protein interactions.

Development of low-fat and anthocyanin-rich purple sweet potato vacuum fried chips

Vacuum frying technology has proven to be one of the best methods to produce snack products with higher retention of health-promoting/protecting nutraceuticals with reduced-fat content. In this work, application and optimization of vacuum frying process for purple sweet potato have used response surface methodology-based Box-Behnken design to produce low-fat and anthocyanin-rich purple sweet potato vacuum fried chips. The study showed the significant impact of frying temperature, vacuum pressure, and frying time on the chip's moisture and oil content, level of anthocyanin, visual impressions like color and texture. The selection of optimized frying parameters was carried out using a numerical optimizer and found to be 105°C for 7.08 min at a reduced pressure of 14.79 kPa. Compared to the atmospheric deep-fried chips, the vacuum fried chips showed 86% retention of anthocyanin content and a 35.6% decline in oil content with a lower breaking force of 0.69 N. Overall, the study confirmed that vacuum fried purple sweet potato chips could be a viable option to produce snacks with high functional value to meet the current consumer demands. PRACTICAL APPLICATION: Purple sweet potatoes have the potential to produce healthy snack chips with lower fat content and higher functional characteristics when vacuum frying technology is used with optimized processing variables.

Biodegradable Films of PLA/PPC and Curcumin as Packaging Materials and Smart Indicators of Food Spoilage

Bio-based and biodegradable packaging combined with chemical sensors and indicators has attracted great attention as they can provide protection combined with information on the actual freshness of foodstuffs. In this study, we present an effective, biodegradable, mostly bio-sourced material ideal for sustainable packaging that can also be used as a smart indicator of ammonia (NH₃) vapor and food spoilage. The developed material comprises a blend of poly(lactic acid) (PLA) and poly(propylene carbonate) (PPC) loaded with curcumin (CCM), which is fabricated via the scalable techniques of melt extrusion and compression molding. Due to the structural similarity of PLA and PPC, they exhibited good compatibility and formed hydrogen bonds within their blends, as proven by Fourier transform infrared (FTIR) and X-ray diffraction (XRD). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis confirmed that the blends were thermally stable at the used processing temperature (180 °C) with minimal crystallinity. The rheological and mechanical properties of the PLA/PPC blends were easily tuned by changing the ratio of the biopolymers. Supplementing the PLA/PCC samples with CCM resulted in efficient absorption of UV radiation, yet the transparency of the films was preserved (T₇₀₀ ∼ 68-84%). The investigation of CCM extract in ethanol with the DPPH^• assay demonstrated that the samples could also provide effective antioxidant action, due to the tunable release of the CCM. Analyses for water vapor and oxygen permeability showed that the PPC improved the barrier properties of the PLA/PPC blends, while the presence of CCM did not hinder barrier performance. The capacity for real-time detection of NH₃ vapor was quantified using the CIELab color space analysis. A change in color of the sample from a yellowish shade to red was observed by the naked eye. Finally, a film of PLA/PPC/CCM was successfully applied as a sticker indicator to monitor the spoilage of shrimps over time, demonstrating an evident color change from yellow to light orange, particularly for the PPC-containing blend. The developed system, therefore, has the potential to serve as a cost-effective, easy-to-use, nondestructive, smart indicator for food packaging, as well as a means for NH₃ gas monitoring in industrial and environmental applications.

Anthocyanins From Clitoria ternatea Flower: Biosynthesis, Extraction, Stability, Antioxidant Activity, and Applications

Clitoria ternatea plant is commonly grown as an ornamental plant and possesses great medicinal value. Its flower is edible and also known as blue pea or butterfly pea flower. The unique feature of anthocyanins present in blue pea flowers is the high abundance of polyacylated anthocyanins known as ternatins. Ternatins are polyacylated derivatives of delphinidin 3,3',5'-triglucoside. This review covers the biosynthesis, extraction, stability, antioxidant activity, and applications of anthocyanins from Clitoria ternatea flower. Hot water extraction of dried or fresh petals of blue pea flower could be employed successfully to extract anthocyanins from blue pea flower for food application. Blue pea flower anthocyanins showed good thermal and storage stability, but less photostability. Blue pea flower anthocyanins also showed an intense blue colour in acidic pH between pH 3.2 to pH 5.2. Blue pea flower anthocyanin extracts demonstrate significant in vitro and cellular antioxidant activities. Blue pea flower anthocyanins could be used as a blue food colourant in acidic and neutral foods. The incorporation of blue pea flower anthocyanins in food increased the functional properties of food such as antioxidant and antimicrobial properties. Blue pea flower anthocyanins have also been used in intelligent packaging. A comparison of blue pea flower anthocyanins with two other natural blue colouring agents used in the food industry, spirulina or phycocyanin and genipin-derived pigments is also covered. Anthocyanins from blue pea flowers are promising natural blue food colouring agent.

Potential Health Benefits of Whole Grains: Modulation of Mitochondrial Biogenesis and Energy Metabolism

Mitochondria play an essential role in maintaining cellular metabolic homeostasis. However, its dysfunction will cause different pathophysiological consequences. A specific mechanism of action has been developed by cells to adapt to changes in physiological conditions or in response to different stimuli, by meditating mitochondrial number, structure, and energy metabolism. Whole grains are considered healthier than refined grains for their higher amounts of bioactive components, with proven multiple health benefits. The modulation of an appropriate mitochondrial function contributes to the bioactive-component-based health improvements. Thus, this review aims to represent current studies that identify the impact of natural bioactive components in whole grains against metabolic disorders by modulating mitochondrial biogenesis and energy metabolism. It seems most attractive to aim nutritional intervention at the prevention or treatment of metabolic abnormalities and hence to target dietary management at improvement of mitochondrial function.

Impact of Simulated Gastrointestinal Conditions on Antiglycoxidant and α-Glucosidase Inhibition Capacities of Cyanidin-3-O-Glucoside

Cyanidin-3-O-glucoside (C3G) is a widespread anthocyanin derivative, which has been reported in vitro to exert potent antioxidant, antiglycation and α-glucosidase inhibition effects. Nevertheless, the physiological relevance of such properties remains uncertain considering its significant instability in gastrointestinal conditions. A simulated digestion procedure was thus instigated to assess the influence of gastric and intestinal media on its chemical integrity and biological activities. HPLC analyses of digested C3G samples confirmed the striking impact of intestinal conditions, as attested by a decomposition ratio of 70%. In contrast, with recovery rates of around 90%, antiglycation, as well as DPPH and ABTS scavenging assays, uniformly revealed a noteworthy persistence of its antiglycoxidant capacities. Remarkably, a prominent increase of its α-glucosidase inhibition activity was even observed after the intestinal phase, suggesting that classical in vitro evaluations might underestimate C3G antidiabetic potential. Consequently, the present data provide novel and specific insights on C3G’s digestive fate, suggesting that the gastrointestinal tract does not profoundly affect its positive action on oxidative and carbonyl stresses. More specifically, it also tends to support its regulating effects on postprandial hyperglycemia and its potential usefulness for diabetes management.

A Review of the Current Knowledge of Thermal Stability of Anthocyanins and Approaches to Their Stabilization to Heat

Anthocyanins are colored valuable biocompounds, of which extraction increases globally, although functional applications are restrained by their limited environmental stability. Temperature is a critical parameter of food industrial processing that impacts on the food matrix, particularly affecting heat-sensitive compounds such as anthocyanins. Due to the notable scientific progress in the field of thermal stability of anthocyanins, an analytical and synthetic integration of published data is required. This review focuses on the molecular mechanisms and the kinetic parameters of anthocyanin degradation during heating, both in extracts and real food matrices. Several kinetic models (Arrhenius, Eyring, Ball) of anthocyanin degradation were studied. Crude extracts deliver more thermally stable anthocyanins than purified ones. A different anthocyanin behavior pattern within real food products subjected to thermal processing has been observed due to interactions with some nutrients (proteins, polysaccharides). The most recent studies on the stabilization of anthocyanins by linkages to other molecules using classical and innovative methods are summarized. Ensuring appropriate thermal conditions for processing anthocyanin-rich food will allow a rational design for the future development of stable functional products, which retain these bioactive molecules and their functionalities to a great extent.

Novel extraction of polyphenols from sour cherry pomace using natural deep eutectic solvents - Ultrafast microwave-assisted NADES preparation and extraction

In this work, new approaches for the green extraction of polyphenols from sour cherry pomace were explored. Three Natural Deep Eutectic Solvents (NADES) systems based on choline chloride (ChCl) as a hydrogen bond acceptor (HBA) and malic acid, urea, and fructose (MalA, Ur, and Fru) as hydrogen bond donors (HBD) were used. NADES systems were prepared by heating and stirring (H&S), ultrasound (US), and microwave (MW) methods. It was found that MW-assisted preparation was the fastest requiring less than 30 s. Polyphenol extraction from cherry pomace was performed also by three mentioned methods, and compared with conventional methods. MW extraction was the most rapid with less than 5 min necessary for the extract preparation. All three NADES systems were highly efficient for anthocyanin extraction, but the most efficient was ChCl:MalA system. Extract based on ChCl:MalA system was for 62.33% more efficient for anthocyanin extraction comparing with the conventional solvent.

Robust and recyclable magnetic nanobiocatalysts for extraction of anthocyanin from black rice

Anthocyanins, which are natural pigments and nutraceuticals, can be extracted from plant materials using enzyme-assisted methods. However, the enzymes used are often expensive, fragile, and hard to recover/reuse. In this study, cellulase and α-amylase were immobilized on amino-functionalized magnetic nanoparticles to prepare a magnetic nanobiocatalyst. The enzymes in this nanobiocatalyst exhibited higher stability and greater catalytic activity than free enzymes, including good thermal stability (50 to 70℃) and pH stability (pH 4.5-7.5). Nanobiocatalyst efficacy was demonstrated by extracting anthocyanins from black rice, with a maximum yield of 266 mg anthocyanin/100 g black rice obtained. After six reuse cycles, cellulase and α-amylase retained around 70% and 64% of their activity, respectively. Immobilization also increased their reusability. In summary, a novel magnetic nanobiocatalyst was developed for extracting anthocyanins from black rice, which may also have other applications within the food industry.

Chemical composition, bioactive compounds extraction, and observed biological activities from jussara (Euterpe edulis): The exotic and endangered Brazilian superfruit

In this article, we reviewed studies on the fruits of the jussara palm (Euterpe edulis Martius), an endangered Brazilian Atlantic Forest palm tree, also coined as "Superfruit." We summarized the chemical components of the pulp and observed biological activities in murine and humans, as well as the best practices involving the extraction of its target compounds, bioavailability, and stability of extracts. Jussara has shown a rich phenolic profile that justifies its antioxidant properties, in addition to a considerable lipidic and energetic value. As the main feature, the fruit possesses large amounts of anthocyanins that can be commercially explored as a food additive or cosmetic colorants. Recent studies emphasized jussara's antioxidant, anti-inflammatory, and cardioprotective capabilities via reshaping of the gut microbiota. Further knowledge is needed to establish bioavailability and optimal serving size, as many of its antioxidant compounds go under chemical bioconversion in the intestinal tract. While extraction of phenolic compounds, anthocyanins, and oils have interesting results, more studies are required in order to reduce the use of conventional organic solvents and improve their stability and shelf life when added to food products, an area in which nanotechnology seems promising.

Matrix- and Technology-Dependent Stability and Bioaccessibility of Strawberry Anthocyanins during Storage

Anthocyanins are often associated with health benefits. They readily degrade during processing and storage but are also dependent on the matrix conditions. This study investigated how strawberry anthocyanins are affected by preservation technologies and a relatively protein-rich kale juice addition during storage. A strawberry–kale mix was compared to a strawberry–water mix (1:2 wt; pH 4), untreated, thermally, pulsed electric fields (PEF) and high-pressure processing (HPP) treated, and evaluated for anthocyanin stability and bioaccessibility during refrigerated storage. The degradation of strawberry anthocyanins during storage followed first-order kinetics and was dependent on the juice system, preservation technology and anthocyanin structure. Generally, the degradation rate was higher for the strawberry–kale mix compared to the strawberry–water mix. The untreated sample showed the highest degradation rate, followed by HPP, PEF and, then thermal. The relative anthocyanin bioaccessibility after gastric digestion was 10% higher for the thermally and PEF treated samples. Anthocyanin bioaccessibility after intestinal digestion was low due to instability at a neutral pH, especially for the strawberry–kale mix, and after thermal treatment. The storage period did not influence the relative bioaccessibility; yet, the absolute content of bioaccessible anthocyanins was decreased after storage. This research further presents that processing and formulation strongly affect the stability and bioaccessibility of anthocyanins during storage.

Polyphenol-Based Microencapsulated Extracts as Novel Green Insecticides for Sustainable Management of Polyphagous Brown Marmorated Stink Bug (Halyomorpha halys Stål, 1855)

The brown marmorated stink bug (Halyomorpha halys Stål, 1855) is an invasive polyphagous species that threatens fruit growing both in the United States and Europe. Many pesticide active ingredients have been studied in H. halys management, but for sustainable fruit growing, which implies the reduction of chemical harm to the environment, new safe insecticides should be implemented into the practice. For this purpose, novel green insecticide based on natural polyphenols of species Stevia rebaudiana (Bertoni) Bertoni and Aronia melanocarpa (Michx.) Elliott 1821 was developed. Stevia leaves (SLE) and Aronia pomace (APE) aqueous extracts were prepared using the ultrasound-assisted extraction method. Optimal extraction conditions for bioactive compounds (total polyphenols, flavonoids, anthocyanins, and flavan-3-ols, respectively) and antioxidant activity were determined using response surface methodology. Bioactive compounds rich SLE and APE were encapsulated in calcium alginate microparticles by the ionic gelation method. Physicochemical characteristics (morphology, size, encapsulation efficiency, loading capacity, and swelling) of microparticles showed very good properties with especially high encapsulation efficiency. Fitting to simple Korsmeyer–Peppa’s empirical model revealed that the underlying release mechanism of polyphenols is Fickian diffusion. SLE loaded microparticles showed very good pesticidal efficiency against Halyomorpha halys, especially on younger larval stages after both contact and digestive treatment. Microparticles loaded with APE did not achieve satisfactory digestive efficiency, but a certain toxic impact has been observed at contact application on all H. halys growth stages. Microparticles loaded with SLS exhibited prolonged insecticidal action against H. halys and could be a potential candidate as a green insecticide whose application could increase fruit growing safety.

STABILITY OF CHITOSAN-TRIPOLYPHOSPHATE COMPLEX-ENCAPSULATED ANTHOCYANIN AT HIGH WATER ACTIVITY

Previous study successfully conducted encapsulation of the purple-fleshed sweet potato’s anthocyanin but the study has yet to reveal the stability of encapsulated anthocyanin. Therefore, this research aims to observe the stability of encapsulated anthocyanin regarding the characteristic of low anthocyanin stability, which depends on environmental factors, such as temperature, pH, humidity, and water activity. The kinetic parameters of stability, including kinetic constant (k), reaction order, and half-life (t1/2), were also studied. Stability testing was conducted in high water activity of 0.75 and various in-cubation temperatures at 16, 25, 35, and 45°C. Un-encapsulated anthocyanin extract was also tested for its stability in the same condition in order to be compared with encapsulated anthocyanin. This study re-vealed that the encapsulated anthocyanin had lower stability than un-encapsulated anthocyanin extract. It was proven by higher kinetic constant and lower half-life of encapsulated anthocyanin for every incubation temperature which was induced by higher pH of encapsulated anthocyanin compared with anthocyanin extract. Besides, high water activity reduced glass transition temperature (Tg), in which encapsulated anthocyanin was in rubbery state. Both encapsulated anthocyanin and anthocyanin extract were degraded following the first order kinetic. Using the Arrhenius equation, it was obtained that the degradation kinetic constant of encapsulated anthocyanin was stated as k= 420.44 exp (-23.33/RT). Meanwhile, k= 1.12x106 exp (-46.70/RT) described degradation of kinetic constant of anthocyanin extract. The stability test re-vealed that the application of encapsulated anthocyanin was not suitable for wet-type food product.

Degradation Kinetics and Shelf Life of N-acetylneuraminic Acid at Different pH Values

The objective of this study was to investigate the stability and degradation kinetics of N-acetylneuraminic acid (Neu5Ac). The pH of the solution strongly influenced the stability of Neu5Ac, which was more stable at neutral pH and low temperatures. Here, we provide detailed information on the degradation kinetics of Neu5Ac at different pH values (1.0, 2.0, 11.0 and 12.0) and temperatures (60, 70, 80 and 90 °C). The study of the degradation of Neu5Ac under strongly acidic conditions (pH 1.0–2.0) is highly pertinent for the hydrolysis of polysialic acid. The degradation kinetics of alkaline deacetylation were also studied. Neu5Ac was highly stable at pH 3.0–10.0, even at high temperature, but the addition of H₂O₂ greatly reduced its stability at pH 5.0, 7.0 and 9.0. Although Neu5Ac has a number of applications in products of everyday life, there are no reports of rigorous shelf-life studies. This research provides kinetic data that can be used to predict product shelf lives at different temperatures and pH values.

Anthocyanin-rich extracts from purple and red potatoes as natural colourants: Bioactive properties, application in a soft drink formulation and sensory analysis

Aqueous extracts from seven coloured potato varieties (three red-fleshed, three-purple fleshed, and one marble-fleshed) were studied for their anthocyanin content, in vitro biological activities, colouring properties and their potential application in the food industry. Acylated glycosides or pelargonidin and petunidin aglycones were identified as the main anthocyanin forms in the red and purple varieties, respectively. The total anthocyanin content among varieties ranged from 478.3 to 886.2 mg/100 g extract. All the extracts presented in vitro antioxidant, antibacterial and antifungal activities, whereas no toxic effects were detected. Finally, two selected extracts were tested as colourants in a soft drink formulation and presented suitable sensory profiles as well as high colour stability during a 30-day shelf-life when compared with the commercial colourant E163. Therefore, the tested extracts could be used as natural food colourants and considered for substituting the existing synthetic colouring agents.

Thermal Degradation Kinetics of Anthocyanins Extracted from Purple Maize Flour Extract and the Effect of Heating on Selected Biological Functionality

The thermal degradation of the anthocyanins and antioxidant activity in purple maize extracts was determined between 80 and 180 °C. The anthocyanins were found to be thermostable in the temperature range of 80 to 120 °C, whereas at higher temperatures the thermal degradation of both anthocyanins and antioxidant activity followed a first-order kinetic model. The z-values started from 61.72 ± 2.28 °C for anthocyanins and 75.75 ± 2.87 °C for antioxidant activity. The conformational space of pairs of model anthocyanin molecules at 25 and 180 °C was explored through a molecular dynamics test, and results indicated the occurrence of intermolecular self-association reactions and intramolecular co-pigmentation events, which might help explaining the findings of the degradation kinetics. The relationship between thermal degradation of anthocyanins and antioxidant activity and the in vitro release was further studied. The unheated extracts showed a high stability under gastric environment, whereas after heating at 180 °C, the digestion ended quickly after 60 min. After simulated intestinal digestion, the anthocyanins were slowly decreased to a maximum of 12% for the unheated extracts, whereas an 83% decrease was found after preliminary heating at 180 °C. The thermal degradation of anthocyanins was positively correlated with the in vitro decrease of antioxidant activity.

Anthocyanins concentration by adsorption onto chitosan and alginate beads: Isotherms, kinetics and thermodynamics parameters

The anthocyanins health benefits are diverse, but numerous factors affect the anthocyanins stability, thus, this work aimed to extract anthocyanins from Pinot Noir grape skins and, afterward, to concentrate them onto edible and safety adsorbents, chitosan and alginate beads, by adsorption operation. Chitosan was obtained from shrimp waste, and alginate was purchased. Batch adsorption experiments were carried out as pH function, and the highest adsorption capacities and removal percentages were, respectively, 216 mg g^-1 and 65% for chitosan beads at pH 8, and 126.4 mg g^-1 and 38% for alginate beads at pH 4. All equilibrium isotherms models were suitable for chitosan beads, while for alginate beads only Langmuir and Freundlich models showed fitting. The thermodynamic parameters demonstrated physical adsorption and endothermic behavior for the chitosan and alginate beads. The pseudo-first order model best described the kinetic behavior for both beads. It was demonstrated that is possible to concentrate the different molecular structures of anthocyanins onto chitosan and alginate beads with high yields.

Stability of Phenolic Compounds in Grape Stem Extracts

Grape stem is rich in phenolic compounds, especially stilbenes. These antioxidants can be degraded during the storage of grape stem extracts for long periods of time. The aim of this work was to analyze the stability of Mazuelo stem extracts during storage at 25 and 40 °C, in two different light conditions (amber and transparent vials). The stability of the antioxidants was studied after 2, 4 and 6 months of conservation. Gallic acid and the quercetin derivative concentration were stable throughout the storage period. In contrast, catechin disappeared from all the extracts in just two months of storage. Anthocyanins were significantly affected by temperature, and light enhanced their degradation when the extracts were kept at 40 °C. Resveratrol and viniferin showed a similar behavior. Their concentration decreased from the beginning of storage, and in both cases, they were significantly affected by both temperature and light.

Antioxidant Content of Aronia Infused Beer

Beer is a fermented beverage in which antioxidants can contribute to the oxidative stability and nutraceutical properties of the product. Aronia berries are antioxidant-rich fruits of distinct sour and astringent taste, limiting their culinary uses. Previously, fermentation has proven to be effective in the removal of astringent tastes from various fruit juices. In this study, a single malt pale ale was produced and infused with Aronia berries under various process conditions by adding the antioxidant-rich fruits at different stages of the beer brewing process. The polyphenol content, antioxidant potential and color were determined. There was a positive correlation between the Aronia amount added and antioxidant capacity. Higher concentrations of added Aronia also increased the polyphenol content and EBC color rating, while no change in the resulting pH was observed. An increase in the Aronia amount increased the attenuation, showing a positive effect on sugar utilization during fermentation. The addition of Aronia after the boil yielded the highest coloration and antioxidative capacity, while addition before the boil yielded a similar antioxidative capacity with a lower EBC rating. Taken together, the infusion of pale ale with Aronia berries can increase the EBC rating, polyphenol content and antioxidative capacity of the beer.

Aronia melanocarpa Fruits as a Rich Dietary Source of Chlorogenic Acids and Anthocyanins: 1H-NMR, HPLC-DAD, and Chemometric Studies

Aronia melanocarpa (Michx.) Elliott's (chokeberry) besides anthocyanins contains significant amounts of hydroxycinnamic acids: Chlorogenic and its isomer neochlorogenic acid. They exhibit antioxidant, anti-inflammatory, antidiabetic, and antibacterial activities, thus they can have a significant impact on the health-promoting properties of Aronia. The aim of our research was to determine the changes in the content of chlorogenic acids (CGAs) and anthocyanins during fruit development and ripening, with a particular emphasis on acids. Aronia fruit samples were collected from July to October on two organic farms in Poland. The chemical composition of the extracts was determined by NMR spectroscopy and HPLC-DAD. ¹H-NMR and HPLC data were analyzed using chemometric analysis and multivariate statistics (PCA). The results showed that the content of chlorogenic acids and anthocyanins changes during ripening and depends on the time of harvest and the region of cultivation. A correlation between the time of CGAs reduction and the appearance of anthocyanins was also noticed. The result of our research was also a database in the form of NMR parameters, which allows analysis of the metabolite profile and tracking of its changes. The ¹H-NMR spectrum showing anthocyanin and CGA resonance can be considered the Aronia berry fingerprint.

Anthocyanin Colorimetric Strip for Volatile Amine Determination

Food freshness is one of the main concerns of consumers. Food spoilage is mainly caused by contamination and microbial growth in which the latter produces volatile amines in the process. Several methods have been used to determine volatile amines to indicate food freshness, and indicator films are deemed as the most time-efficient and economical. In this study, anthocyanin was extracted from mangosteen rind as a natural dye indicator and was incorporated in a chitosan/PVA polymer matrix. The film with different concentrations of anthocyanin extract (5%, 15%, and 25%) was prepared and tested for their sensitivity to 136 ppm ammonia vapor followed by colorimetric analysis using ImageJ software. The film with 25% anthocyanin yielded the most visible color change upon exposure to ammonia vapor. The color changed from pink to yellowish-brown within 14 minutes of exposure. The RGB-converted images of the film with 25% anthocyanin extract showed gradual loss of red coloration being replaced by cyan spots. FTIR spectra showed incorporation of anthocyanin to the chitosan/PVA matrix with the decrease in the intensity of the C-N stretching peak. Thermogravimetric analysis showed that the film has high thermal stability with onset temperature of 310.43°C. Thus, the film developed is an excellent candidate for optimization and production of a thermally stable amine detector for food products.

Betacyanin as Bioindicator Using Time-Temperature Integrator for Smart Packaging of Fresh Goat Milk

Smart packaging is a packaging system with embedded sensor or indicator technology, which provides information on the quality of the product, especially perishable foods such as goat milk. One application of smart packaging is to use a time-temperature bioindicator. The purpose of this study was to determine the quality of fresh goat milk during storage at freezing temperatures (-20 ± 2°C) for 31 days and room temperature (25 ± 3°C) for 24 hours using a time-temperature indicator by utilizing a natural dye betacyanin. The method used was descriptive analysis, and the data obtained were processed using the correlation regression test. The samples were observed at freezing temperature every 24 hours and room temperature at 0, 1, 2, 3, 4, 5, 6, 8, 10, and 24 hours. The observation criteria consisted of changes in bioindicator color, milk pH, and total microbes. The results showed that color changes of the bioindicator film at room temperature were more noticeable than at freezing temperature. Based on changes in color of the bioindicator at room temperature, the sample was safe for consumption until the 5th hour with pH 6.51, and the biofilm color characteristics were L∗ = 82.49, a∗ = 21.46, and b∗ = -7.33, but the total number of microbes did not fulfil Indonesian National Standard at the 24th hour, i.e., 1.36 × 10⁶ CFU/ml. At freezing temperatures, fresh goat milk was still safe for consumption until the 31st day with pH 6.51 and total microbe of 1.89 × 10⁵ CFU/ml, and the biofilm color characteristics were L∗ = 80.52, a∗ = 24.15, and b∗ = -7.91. The results of this study concluded that the milk expiration limit based on the betacyanin indicator was 5 hours at room temperature and 31 days at freezing temperature.