Valorisation of black carrot pomace: microwave assisted extraction of bioactive phytoceuticals and antioxidant activity using Box–Behnken design

The present study compares three methods viz. microwave assisted extraction (MAE), ultrasonic-assisted extraction (UAE) and conventional solvent extraction (CSE) for extraction of phenolic compounds from black carrot pomace (BCP). BCP is the major by-product generated during processing and poses big disposal problem. Box–Behnken design using response surface methodology was employed to investigate and optimize the MAE of phenolics, antioxidant activity and colour density from BCP. The conditions for maximum recovery of polyphenolics were: microwave power (348.07 W), extraction time (9.8 min), solvent–solid ratio (19.3 mL/g) and ethanol concentration (19.8%). Under these conditions, the extract contained total phenolic content of 264.9 ± 10.02 mg gallic acid equivalents (GAE)/100 mL, antioxidant capacity (AOC) of 13.14 ± 1.05 lmol Trolox equivalents (TE)/mL and colour density of 68.63 ± 5.40 units. The total anthocyanin content at optimized condition was 753.40 ± 31.6 mg/L with low % polymeric colour of 7.40 ± 0.42. At optimized conditions, MAE yielded higher colour density (68.63 ± 5.40), polyphenolic content (264.9 ± 10.025 mg GAE/100 mL) and AOC (13.14 ± 1.05 lmol TE/mL) in a short time as compared to UAE and CSE. Overall results clearly indicate that MAE is the best suited method for extraction in comparison to UAE and CSE. The phenolic rich extract can be used as an effective functional ingredient in foods

Synergistic effects of nutmeg and citrus peel extracts in imparting oxidative stability in meat balls

Nutmeg (NM) and citrus peel (CP) extracts are potential sources of phytochemicals high in antioxidant activity. The synergistic effect of the extracts when incorporated as a binary mixture (NM-CP) demonstrated high antioxidant activity, exceeding the expected values indicating possible interactive synergism. This effect prompted us to investigate the potential of NM, CP and NM-CP extracts in imparting oxidative stability to meat balls during frozen storage. NM-CP was evaluated at two concentrations 0.5% (NMCP) and 1.0% (NMCP1). Meat balls with added salt (MS) and control (without any salt and antioxidant) served as control. Binary mixture (NM-CP) at 1% showed a stronger inhibitory effect on lipid oxidation in comparison to the NMCP and individual extracts NM and CP. However, with respect to protein oxidation, both concentrations (NMCP and NMCP1) exhibited higher inhibitory activity than the individual counterparts. Color, flavor and sensory scores further confirmed the efficacy of NM-CP in extending the storage life of frozen meat. Synergistic effect of binary extract NMCP in retarding lipid and protein oxidation in meat balls could be of practical value for meat processors

Targeted Metabolomics Approach to Study Secondary Metabolites and Antioxidant Activity in ‘Kinnow Mandarin’ during Advanced Fruit Maturity

In this study, we investigated the impact of harvest maturity stages and contrasting growing climates on secondary metabolites in Kinnow mandarin. Fruit samples were harvested at six harvest maturity stages (M1–M6) from two distinct growing locations falling under subtropical– arid (STA) and subtropical–humid (STH) climates. A high-performance liquid chromatographytandem mass spectrometry (HPLC-MS/MS) technique was employed to identify and quantify secondary metabolites in the fruit juice. A total of 31 polyphenolics and 4 limonoids, with significant differences (p < 0.05) in their concentration, were determined. With advancing maturity, phenolic acids and antioxidant activity were found to increase, whereas flavonoids and limonoids decreased in concentration. There was a transient increase in the concentration of some polyphenolics such as hesperidin, naringin, narirutin, naringenin, neoeriocitrin, rutin, nobiletin and tangeretin, and limonoid aglycones such as limonin and nomilin at mid-maturity stage (M3) which coincided with prevailing low temperature and frost events at growing locations. A higher concentration of limonin and polyphenolics was observed for fruit grown under STH climates in comparison to those grown under STA climates. The data indicate that fruit metabolism during advanced stages of maturation under distinct climatic conditions is fundamental to the flavor, nutrition and processing quality of Kinnow mandarin. This information can help in understanding the optimum maturity stage and preferable climate to source fruits with maximum functional compounds, less bitterness and high consumer acceptabilit

Encapsulation efficiency and fatty acid analysis of chia seed oil microencapsulated by freeze-drying using combinations of wall material

Chia seed oil (CSO) was encapsulated using whey protein concentrate (WPC) and modified tapioca starch (MTS) through freeze-drying. A central composite design was used to evaluate the effect of independent variables (MTS:WPC ratio, homogenization pressure, and oil content). Encapsulation efficiency (EE) and α-linolenic acid content (ALA) were evaluated for all runs. The results showed that higher MTS ratios led to maximum ALA retention, while higher WPC ratios led to maximum EE. The optimized conditions resulted in high EE (97 %), ALA content (59.54 %), and a Ω-3:Ω-6 ratio (3.34). The fatty acid composition, oxidative and thermal stability showed that the MTS:WPC ratio of 25:75 was the best combination for encapsulating CSO. The encapsulated CSO with a balanced Ω-3:Ω-6 ratio can be used as a functional ingredient in foods for health benefits

Stability enhancement of beetroot betalains through copigmentation

Background Like other natural pigments, betalains also face stability problem. Copigmentation can be explored to address this issue. In this study, black carrot anthocyanins were first time used as copigment with betalains so that copigmented betalains with enhanced stability could be developed that can withstand the deteriorative processing and storage conditions. Results Increase in hyperchromic and bathochromic shift with subsequent increase in black carrot anthocyanins extract (0.250 g L-1) addition from 0.2 to 1.0 ml L-1 was observed in native betalains pigments from 0.28 to 1.90 and 538 nm to 564 nm, respectively. For maximum recorded bathochromic shift, 0.8 ml L-1 addition of copigment was optimized. Copigmented betalains pigment showed better stability in comparison with native pigment, when exposed to light, temperature more than 60oC, and ≥1.0 g L-1 NaCl. At constant incubation time (3h), copigmented betalains degraded up to 20.79-41.43% whereas the non-copigmented counterpart degraded up to 83.49-86.86% at 60, 75 and 90°C, respectively. Lower rate constant (k) and enhanced activation energy (Ea) showed higher thermostability of copigmented betalains. With constant light exposure, the half-life value of betalains was 145.2h which increased approximately by two-fold (274.08h) after copigmentation. The t1/2of betalains pigment at 10, 15 and 18% salt addition was 81.12, 75.36 and 83.52h which increased to 186.96, 226.56 and 152.88h after copigmentation. Conclusion These findings support that black carrot anthocyanin, is a potential and compatible copigment for water soluble betalains pigment which enhances stability of betalains under extreme processing conditions

Chemical additives for preserving the betalain pigment and antioxidant activity of red beetroot

Beetroot is one of the most important industrial crops from Caryophyllales order cultivated for its natural colourant, betalains and exceptionally high antioxidant activity. Like other natural pigments, betalains are also associated with reduced stability problem. The effectiveness of various additives for betalain and antioxidant stability was examined in this study. Beetroot (Beta vulgaris L.) cv. Crimson Globe was harvested at the physiological maturity stage used for this study. Each additive was added as per the prescribed limits given by Food Safety and Standards Authority of India (FSSAI) for food uses. Data on total betalain content, total colour change and total antioxidant activity in terms of CUPRAC were recorded after every 24-h interval till significant degradation was recorded in all incubations. Additives, namely 1% ascorbic acid, 10% glucose/ fructose, sucrose [45%, EDTA 40 ppm and sodium benzoate 350 ppm, were found best for imparting maximum betalain stability. A lower concentration of salt (\3.0%) was the best to impart stability of betalain pigments and antioxidant activity in beetroot extract. Almost in all incubations, betalains and colour degradation followed a similar trend; however, antioxidant activity was not the exact replica of betalain content. The stability of the pigment was confirmed by enhanced halflife and lower rate constant under first-order degradation kinetics

Black carrot (Daucus carota ssp.) and black soybean (Glycine max (L.) Merr) anthocyanin extract: A remedy to enhance stability and functionality of fruit juices by copigmentation

Pomegranate (Punica granatum L.) can suffer from sunburn and fruit cracking, and biotic stresses such as bacterial blight (Xanthomonas axonopodis pv. Punicae) (Hingorani and Singh) Dye and fruit borer (Deuodorix isocrates Fabr.). Because particle film technology has emerged as a promising technology, many kaolin-based films such as Surround WP®, Parasol® and Anti-stress-500®, have been developed. Hence, a study was conducted to observe the effects of Surround WP® on ‘Kandhari’ pomegranate. For this, five sprays of Surround WP® (3%) were made during the fruiting season of 2015 and 2016 in randomly selected ‘Kandhari’ pomegranate bushes, starting from June 15, at fortnightly interval every year, in addition to non-sprayed control pomegranate bushes. Observations on biotic, abiotic stresses and quality attributes were recorded after harvesting fruit. The results revealed that pre-harvest sprays of Surround WP® reduced the sunburn and fruit cracking in ‘Kandhari’ pomegranates by 47% and 46%, respectively, and the incidence of both fruit borer and bacterial blight by 50.3 and 40.2%, respectively. The Surround WP®-treated pomegranates exhibited 46.4% higher cosmetic appeal, developed 19.5% higher red colour, and contained 17.4% higher levels of total anthocyanin content than untreated (control) fruit. Similarly, Surround WP®- treated fruit had significantly higher total phenolic content, antioxidant activity, higher juice recovery (18.2%) and soluble solid content (5.6%) but exhibited nearly 35.9% lower lipoxygenase activity than untreated pomegranates. Thus, this technology has potential to be adopted in pomegranate production

Evaluation of enzyme and microwave-assisted conditions on extraction of anthocyanins and total phenolics from black soybean (Glycine max L.) seed coat

The present study compares three methods viz. microwave-assisted extraction (MAE), enzyme-assisted extraction (EAE) and conventional solvent extraction (CSE) for extraction of polyphenolic compounds from Black Soybean Seed coat (BSSC). Box-Behnken design using response surface methodology (RSM) was employed to investigate and optimize the MAE and EAE for maximum bioactive content, antioxidant activity, colour density and minimum degradation parameters from BSSC. Optimized MAE conditions for BSSC were: microwave power of 569.46 W, extraction time of 262.54 s, solvent to solid ratio of 40:1 and ethanol concentration (59.99). The predicted anthocyanin content was 5021.47 mg/l, close to experimental optimized value of 5094.9 mg/l with minimum values of degradation parameters viz., Polymeric Colour (PC) (0.131 ± 0.01), Browning Index (BI) (0.202 ± 0.02) and Degradation Index (DI) (0.140 ± 0.02). Overall results clearly indicate that MAE is the best suited method for extraction in comparison to EAE and CSE. The phenolic rich extract can be used as an effective functional ingredient in foods

Ultrasound-assisted development of stable grapefruit peel polyphenolic nano-emulsion: Optimization and application in improving oxidative stability of mustard oil

Grapefruit (Citrus paradisi) peel (GP) is rich in flavonoids and phenolics which have several proven pharmacological effects. However, their chemical instability towards oxygen, light and heat limits its applications in food industries. In the present study, we evaluated the feasibility of fabricating grapefruit-peel-phenolic (GPP) nano-emulsion in mustard oil using ultrasonication. Response surface methodology (RSM) optimization revealed that sonication time of 9.5 min at 30% amplitude and 0.52% Span-80 produced the stable GPP nano-emulsion with a droplet size of 29.73 ± 1.62 nm. Results indicate that both ultrasonication and Span-80 can assist the fabrication of a stabilized nano-emulsion. This study is one of its kind where nano-encapsulation of GPP into W/O emulsion was done to stabilize the active compound inside mustard oil and then the nano-emulsion was used to extend oxidative stability of mustard oil. Findings provide a basic guideline to formulate stable nano-emulsions for their use in active food packaging, oils, and pharmaceuticals

Bacterial volatile mediated suppression of postharvest anthracnose and quality enhancement in mango

Anthracnose disease incited by Colletotrichum gloeosporioides reduces the yield and market-quality of mangoes worldwide. Previous studies have indicated the potential of diverse antimicrobial volatile organic compounds emitted by the endophytic Pseudomonas putida BP25 for plant disease suppression. In the present study, we have explored native-volatiles of Pseudomonas putida BP25 and a synthetic-volatile, 2-ethyl-5-methylpyrazine, earlier identified in volatilome of Pseudomonas putida BP25 for reducing anthracnose in mango cultivar, Amrapali. The bacterial volatile compounds displayed fungistatic effects on the mycelial growth of Colletotrichum gloeosporioides in vitro. In planta prophylactic fumigation of mangoes with native-volatiles or the bacterial origin synthetic 2-ethyl-5-methylpyrazine for 24 h at 25 °C showed a reduction of anthracnose severity (>76 % reduction over mock) on fruit. Additionally, physicochemical qualities such as total-soluble solids, total-phenols, total-proline, total-carotenoid, total-flavonoid, and fruit-firmness were increased in fumigated fruit as compared to untreated mangoes. Anthracnose suppression coupled with the fruit quality enhancement by bacterial volatiles and synthetic 2-ethyl-5-methylpyrazine presents a new opportunity for postharvest management of mango during the storage, transit, and trade