Chlorine dioxide and sodium diacetate treatments in controlled atmospheres retard mold incidence and maintain quality of fresh walnuts during cold storage

Girdling Effects on Fruit Maturity, Kernel Quality, and Nutritional Value of Walnuts (Juglans regia L.) alongside the Effects on Leaf Physiological Characteristics

“…The present results of FAs exhibit higher OL and LN values and lower LL than in another study of semi-dried 'Franquette' [48]. The oil fractions of total saturated (SFA), unsaturated (TUFA), and polyunsaturated (PUFA) FA are in good agreement with other fresh walnut studies [6,38,39]. The ratio of ω-6/ω-3 (LL/LN) render them highly beneficial to human health and unique among nuts that predominantly have MUFA as the major fraction [49].…”

“…The values of the color parameters recorded at both harvests (Table 1) corresponded to an extremely light color of kernels with excellent appearance, close to the color of the same cultivar studied in a previous work [5], comparable to raw kernels of 'Chandler', 'Hartley', and 'Ioli' [37], 'Xifu No.1 [38], and to a semi-dried 'SKAU-02 genotype [39]. At late harvest, the reduced values of L * and h o and the increased of C * due to walnut maturation when kernels acquired a darker yellowish color, being in agreement with other studies [12,36,37], could be attributed, at least partially, to the increased oil content [40].…”

“…In all samples, the values of FFA and PV were extremely low, as shown in Figure 2 (<0.028% and <0.058 meq O 2 kg −1 , respectively), indicating the very low free FA (FFA) formed by enzymatic hydrolysis of triglycerides and low oxidative rancidity, respectively, and resulting in oil kernel free from off-flavors. These values were stable during fruit development, not affected by girdling, lower than in other studies on fresh [10,38] or dried [47] kernels and corresponded to oil of exceptional quality.…”

“…Fresh 'Franquette' kernels exhibited similar values with another study [5] and higher antioxidant levels than other cultivars [37]. In another walnut genotype, TP and FRAP also exhibited a reducing pattern during maturation, with values being approximately 2.5-fold higher than here, but the kernels were semi-dried (kernel moisture 7.0% w/w) [39], whereas in 'Xifu No.1 the TP levels were much lower than these ones [38]. In some olive cultivars, a reduction of phenolics has been found during development and ripening [32].…”

Physiochemical Responses of the Kernel Quality, Total Phenols and Antioxidant Enzymes of Walnut in Different Forms to the Low-Temperature Storage

“…Many studies have reported that phenolic compounds can contribute to the lower acid value, peroxide, which in turn could improve the kernel quality of nuts during storage. In fresh walnuts, Wang et al (2016) and Ma et al (2020) observed that phenols played a primary role in reducing the lipid oxidation in the kernels, resulting in a negative correlation between the phenol content and the concentration of acid value and peroxide value [ 10 , 38 ]. In hazelnuts, a study found that frozen storage at −25 °C maintained the kernel quality as a result of the high phenolic composition and antioxidant capacity of kernels during the storage [ 27 ].…”