Protein and polysaccharide based encapsulation of ginger oleoresin: impact of wall materials on powder stability, release rate and antimicrobial characteristics.

Ginger oleoresin is widely used as a flavouring agent in many foods. But its bioactive components are unstable as being sensitive to heat, humidity and light. Hence this study proposes the encapsulation of ginger oleoresin in order to protect it and regulate its release in the gastrointestinal system via spray drying utilising whey protein isolate (WPI) and gum Acacia (GA) as wall materials. The feed emulsions used were characterised for emulsion stability, viscosity, droplet size and thermal properties. The GA microcapsules had a substantially greater mean particle diameter (1980 nm) than WPI microcapsules (1563 nm). The WPI microcapsules retained high content of 6-and 8-gingerol (89.57 and 12.54 mg g-1) compared to GA. The WPI microcapsules showed the largest mean inhibition zone with diameter of 16.64 mm against Escherichia coli and 22.68 mm against Staphylococcus aureus making them most effective in preventing the growth of test bacteria. Both WPI and GA microcapsules exhibited zeta potential value in the range of (-21.09 to -27.35 mV) indicating excellent colloidal stability. The highest concentration of antioxidant activity (73.33 %) and total phenols (33.92 mg g-1) was retained by WPI microcapsules in intestinal juice which ensures intestinal regulatory release.

Effect of excipient wall materials on the development of ginger oleoresin microcapsules: assessing the physicochemical, antioxidant and structural properties.

BACKGROUND: Ginger oleoresin is prone to destruction from air, light and high temperatures and has a limited shelf life if kept improperly. Its viscous and sticky characteristics also make it difficult to handle and utilize. These issues can be solved via microencapsulation. The goal of this research was to evaluate how different wall materials affect the properties of microencapsulated ginger oleoresin powder. RESULTS: Ginger oleoresin microcapsules were developed through spray drying technique using gum acacia (GA) and whey protein isolate (WPI) as wall materials. The characteristics of the obtained powder, including water activity, wettability and encapsulation efficiency, were evaluated, corresponded to values of 0.20, 90.54 s and 84.15% for whey protein isolate-based ginger oleoresin powder. Whey protein isolate microcapsules also exhibited higher phenolic content (27.26 mg gallic acid equivalents g-1 ), total flavonoid (2.94 mg quercetin equivalents g-1 ) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (68.71%) than GA microcapsules. Both WPI- and GA-based oleoresin microcapsules displayed poor flowability, but possessed a metastable amorphous state as indicated by X-ray diffraction. GA-encapsulated oleoresin microcapsules showed a significant increase in particle size (1983 nm) compared to WPI oleoresin microcapsules. Fourier transform infrared analysis of the developed oleoresin microcapsules indicated no change in molecular structure except for a variation in peak intensity. CONCLUSION: Whey protein isolate proved to be more efficient in maintaining the physicochemical and antioxidant activity of spray-dried ginger oleoresin powder. The present study revealed whey protein-based oleoresin powder could be used as a therapeutic agent in various nutraceutical applications. © 2022 Society of Chemical Industry.

Changes in concentration of pesticide residues in fruits and vegetables during household processing.

Monitoring of pesticide residues in fruits and vegetables and their processed products like jams, pickles, juices, ketchup, dried products and canned products was undertaken. The study was conducted to assess the effect of washing, peeling, heating and cooking on concentration of various pesticides. The stability of various pesticides in samples and their products was assessed. Pesticide residues were extracted using QuEChERS method and analysed by GC-MS. It was observed that pesticides like mancozeb and carbofuron were found to be stable for tomato and potato while chloropyriphos, captan and mancozeb (in other samples) were found to be unstable. It was also observed that peels and pomace showed highest levels of pesticide residues. In this study, washing, peeling and heat processing (boiling and blanching) have been found to be the most effective ways of pesticide residue dissipation.

Effect of cold storage on Carbofuran dissipation in Cabbages (Brassica Oleracea).

Cabbage being a highly imported product is often subjected to long term cold storage to maintain product quality and in order to retain its freshness it is kept in cold chambers for a long time. Being highly infested by pests during storage, cabbages are often treated with insecticides having active ingredients such as carbofuran in them. Also, large number of malpractices have come into the notice of the regulatory bodies where the growers use last minute Carbofuran dips on the cabbage heads to improve the shine and lustre of the foliage for better marketability .Therefore, the study was conducted to monitor the effect of cold storage on degradation pattern of Carbofuran on Cabbage during storage in Kashmir valley. The level of carbofuran residue decreased with an increase in storage period Dissipation pattern was studied for three application rates of Carbofuran by dipping the samples in T1 (First dose) 3g/1000mL, T2 (Second dose) 2g/1000mL, T3 (Third dose) 1g/1000mL. The initial control deposit was found to be 0.05mg/kg for T1, 0.03mg/kg for T2, 0.01mg/kg for T3 on Cabbage. The residues were dissipated to about 0.02mg/kg in T1, 0.01mg/kg in T2 and ND in T3 after 60 days of application. The waiting period after proper risk assessment was calculated and was found to be 30 days for almost all application rates.

Effect of gum Arabic, xanthan and carrageenan coatings containing antimicrobial agent on postharvest quality of strawberry: Assessing the physicochemical, enzyme activity and bioactive properties.

Effect of edible coatings of gum Arabic, carrageenan and xanthan gum containing lemon grass essential oil 1% w/v on postharvest quality of strawberry was studied under refrigeration for a period of 12 days. Results showed all the three coatings maintained fruit quality parameters during storage compared to control. Among all the coatings, carrageenan coated fruits showed delayed weight loss (10.1 to 8%), decay percentage (78.42 to 14.29%), retained ascorbic acid (0.15 to 0.27 g kg-1), antioxidant activity (18.17 to 25.85%), firmness (9.07 to 12.43 N), L* (32.38 to 40.42), a* (16.08 to 17.22) and b* (27.36 to 33.54). Carrageenan gum also showed lowest cellulase activity (0.03 units h-1 mg protein-1), pectin methylesterase activity (1.13 A620 min-1 mg protein-1) and ß-galactosidase activity (0.51 µmol min-1 mg protein-1), while showed maximum reduction in polygalacturonase activity (0.07 units h-1 mg protein-1) at the end of storage. Carrageenan gum was found effective in retention of anthocyanins and phenolic compounds during storage. Coatings loaded with antimicrobial agent inhibited psychrophilic bacteria, yeast and mold growth. It is concluded that carrageenan gum could better retain strawberry quality up to 12 days under refrigeration.

Effect of storage temperatures, packaging materials and storage periods on antioxidant activity and non-enzymatic browning of antioxidant treated walnut kernels.

The effect of antioxidants, temperature, packaging materials and storage periods was investigated in medium shelled walnut kernels (Hamdan) variety. The kernels were mechanically dried (40 °C), standardized and treated with butylated hydroxylanisole and butylated hydroxytoluene in combination at concentrations (0.015%) each. Then packed in laminates under vacuum and high density polyethylene non vacuum packaging materials and stored under ambient and refrigerated temperature conditions (4 °C) for a period of 9 months. All tested extracts possessed appreciable antioxidant potential. The bioactive compounds were identified by using chromatographic techniques (GC-MS and LC-MS). Before storage dried kernels exhibited high values of total phenols (31.23 mgGAE/gm), DPPH (215.13 µmol TAEg-1) and low value of non enzymatic browning (0.63 OD). Walnuts packed in laminates under vacuum and refrigerated conditions exhibited higher values of total phenols, total flavonoids, DPPH and subsequently lower change in non-enzymatic browning reactions throughout the experiment. After 90 days of storage maximum loss in total phenols and DPPH value and highest value of non enzymatic browning was observed in high density polyethylene non vacuum packaging materials under ambient temperature. The major phenolic components identified by GC/MS and LC/MS analysis were linoleic acid, oleic acid, hexadecanoic acid, epicatechin, quercetin, epicatechin and ellagic acid respectively. This study validates the antioxidant potential of the walnut kernels and the positive relationship between total phenolic content, total flavonoids and antioxidant activity.

Development of walnut dehulling machine and assessment of its performance using Ethephon and Tween-80 as pre-treatments for hull loosening.

A power- driven walnut dehulling machine was developed and tested. The machine was evaluated for dehulling after applying Ethephon and Tween-80 to green walnuts by dip and spray methods. The results showed that with the increase in dipping time and post dipping/spraying time, the effective throughput capacity, dehulling efficiency and fully dehulled walnut percentage increased, whereas partially dehulled walnut percentage and labour requirement decreased in both manual and mechanical dehulling. Maximum effective throughput capacity, dehulling efficiency and fully dehulled walnut percentage were observed, when green walnuts were subjected to dehulling after 4 days of Ethephon spray treatment (0.3 %). The effective throughput capacity, dehulling efficiency and fully dehulled walnut percentage were found significantly higher in mechanical dehulling than in manual dehulling.