Efficacy of chitosan nanoparticles and wax coatings on maintaining post-harvest quality of "Murcott" mandarins.

Because of its high degree of biodegradability, chitosan is widely used as a component in food packaging. However, its poor physical properties, such as permeability, limit its applicability. Consequently, applying nano chitosan is regarded as the most effective solution to this issue. In the current study, we studied the effect of using different materials in the coating process on the quality of "Murcott" mandarin during cold storage. We used different concentrations of nano chitosan (50 and 100 ppm) without wax and 100 ppm nano chitosan with wax. We investigated the impact of these compounds on the chemical composition and quality of fruits. The most successful treatment for preventing weight loss from discarded fresh fruit was a combination of wax and 100 ppm nano chitosan. This combination also prevented the deterioration of vitamin C, maintained the fruit pulp, and preserved the fruit's superior taste during cold storage and shelf life. It also maintains a better total soluble solids and total acidity level than other treatments. In addition, the activity of antioxidant enzymes and the total number of antioxidants indicates no degradation of plant tissues compared to those not coated with nano chitosan. It also reduces the microbial load on the coated fruits. Consequently, this coating combination could suggest prolonging post-harvest life and increasing the marketing period of mandarin fruits.

Effect of Inorganic and Organic Nitrogen Sources and Biofertilizer on Murcott Mandarin Fruit Quality.

Mandarin 'Murcott' (Citrus reticulata Blanco) trees aged five years that were grafted onto lemon 'Volkamer' (Citrus volkameriana) rootstock and grown in sandy soil under a drip irrigation system were used in this study during the growing seasons of 2018 and 2019. Ten different fertilization treatments combining inorganic, organic, and biofertilization in a completely randomized block were performed. The results revealed that fertilizing 'Murcott' mandarin trees with 75% of the recommended dose (RD) of nitrogen as inorganic nitrogen (33.5% N) in the form of NH4NO3 + 25% of RD as organic nitrogen in the form of chicken manure (3% N) per tree per year without or with a biofertilizer (Effective Microorganisms, EM1) at 150 mL/tree increased the weight, size, pulp, and peels of mandarin fruit, as well as the fruit juice volume, juice volume/fruit, and vitamin C, but reduced the total acidity in both seasons. However, fertilizing 'Murcott' mandarin trees with 100% of RD as inorganic nitrogen increased the pulp/fruit ratio, and fertilizing with 25% of RD as inorganic nitrogen + 75% of RD as organic nitrogen + biofertilizer EM1 increased the peel/fruit ratio, peel thickness, and fruit firmness. Fertilizing 'Murcott' mandarin trees with 100% organic nitrogen + biofertilizer EM1 increased total soluble solids (TSS) and total sugar contents while producing the lowest nitrate (NO3) percentage in 'Murcott' mandarin fruit compared with trees fertilized with inorganic nitrogen only. The fruit produced by 'Murcott' mandarin trees fertilized with 100% of RD as organic nitrogen with or without biofertilizer EM1 contained higher TSS, total carbohydrates, and sugars and lower nitrate percentages than those fertilized with inorganic nitrogen and biofertilizer EM1. This study contributes to reducing the use of inorganic fertilizers by adding a percentage of an organic fertilizer to obtain a healthy product that contains a lower percentage of NO3, which affects the health of the consumer, and is of high quality and suitable for export.

Use of fumaric acid as a feed additive in quail's nutrition: its effect on growth rate, carcass, nutrient digestibility, digestive enzymes, blood metabolites, and intestinal microbiota.

To investigate the effects of dietary fumaric acid (FUA) on performance, carcasses, nutrient digestibility, blood metabolites, digestive enzymes, and cecal microbiota in Japanese quail chicks. Three hundred unsexed Japanese quail (1-wk-old) were randomly assigned to 5 groups. Supplementation of FUA in the diet of Japanese quail chicks exhibited a significant improvement in growth performance through the different experimental periods studied compared with those receiving unsupplemented one. The digestibility of crude protein (CP) and metabolizable energy (ME) were improved with 10 and 15 g/kg FUA, respectively. Apart from lipase enzyme, birds fed 5 and 15 g/kg FUA recorded higher activity of amylase. There were no significant changes among experimental groups on the relative weights of carcass, gizzard, heart, and dressing. Dietary supplementation of FUA at different levels (P> 0.05) increased total protein (TP) and globulin (GLB) concentrations and A/G % compared with control group. A significant (P < 0.01) decrease in plasma low density lipoprotein (LDL) and total cholesterol (TC) levels and increase in high density lipoprotein (HDL) concentrations were observed in chicks fed with FUA containing diets. Immunoglobulin G (IgG) (P = 0.0026) and M (IgM) (P = 0.0007) levels were greater in groups treated with either 10 or 15 g FUA/kg diet. A significant increase in plasma Ca concentration was noticed in chicks received 15 g FUA/ kg compared with the other groups. Quail chicks received diets containing FUA at different levels exhibited reduced cecal count of coliform, E. coli, and Salmonella as compared with control group. In conclusion, supplementation of fumaric acid (especially 15 g/kg diet) in quail chick diets improved their growth, digestibility of nutrients, immune response, antioxidant status, digestive enzyme, and intestinal health.

Dietary citric acid enhances growth performance, nutrient digestibility, intestinal microbiota, antioxidant status, and immunity of Japanese quails.

A total of 300 un-sexed Japanese quail chicks (1-wk-old) were randomly allotted to 5 experimental groups to study the effect of citric acid (CA) on performance development, carcass estimates, blood measurements, antioxidant and immune measurements, digestive enzymes, and cecum microbiology traits of growing Japanese quail. The chicks were fed a basal diet supplemented with CA (5, 10, 15, and 20 g/kg in diet) had significantly (P < 0.05) greater live body weights at 3 and 5 wk of age and increased weight gain across all experimental periods (1-3, 3-5 and 1-5 wks of age) compared to the control group. No significant difference was found in any of the measured carcass traits. The digestion coefficients of crude protein, ether extract, crude fiber, and nitrogen free extract as well as metabolizable energy significantly improved (P < 0.05) in all treatment groups compared to the control. CA supplementation from 10 to 20 g/kg had increased digestive enzyme activities (amylase and lipase). All treatment groups had higher (P < 0.05) albumin and globulin concentrations than the control group. A significant (P < 0.05) decrease in phosphorus (P) concentrations in the plasma was observed in all treatment groups. The IgG levels were greater (P < 0.05) in the 5 or 10 g/kg groups than the control group. Chicks fed CA at different levels had significantly decreased caecal content of TBC, coliform, E. coli, and Salmonella. We concluded that the inclusion of CA (especially 10 g/kg diet) in growing Japanese quail diets improved growth performance, immune response, and health.