Effect of mango kernel starch coatings on the shelf life of almond ( Prunus dulcis ) kernels

Abstract

The effect of mango kernel starch (MKS) coatings on shelf life of roasted almonds was determined. The coating formulations were prepared by gelatinizing 4% MKS in distilled water and plasticized with glycerol, sorbitol, and their 1:1 mixture (50% of starch weight; db). Lipid oxidation was evaluated by peroxide value (PV), thiobarbituric acid reactive substances (TBARS), and p‐anisidine (AV) values. Results showed significant differences in coated and uncoated nuts and the rate of oxidation was significantly low in all coated samples. All coated nuts provided effective protection against oxidation compared with the control, particularly, the sorbitol coated nuts that did not show any sign of deterioration during 100 days of storage at 40 °C whereas in control rancidity appeared just after 50 days. Sensory evaluation of coated nuts also supported the chemical testing outcomes and all the coated nuts received higher scores for color, flavor, and texture than uncoated nuts. Practical applications Almonds have high commercial value and are consumed both in raw or roasted form and also added as an ingredient in many processed foods including confectionary, bakery products, ice creams, and beverages. The quality of almonds deteriorates during storage due to oxidation of its oil content that contains high proportion of oleic acids (unsaturated fatty acids) that are susceptible to oxidation. Among different renewable resources mango kernel starch is abundant but underutilized source of starch which has not been received significant attention from the researchers so far. At present, this inexpensive source of starch is usually ignored and wasted during mango processing; in spite of the fact that most of its properties are comparable to other commercial starches. Therefore, the application of edible coating based on mango kernel starch can make a significant contribution in prolonging shelf life of almonds, while developing healthy and natural foods.

Impact of carboxymethyl cellulose coating enriched with Thymus vulgaris L. extract on physicochemical, microbial, and sensorial properties of fresh hazelnut ( Corylus avellana L.) during storage

“…A similar result was reported by Nawab et al. (2018) for mango starch coatings on almond ( Prunus dulcis ) kernels (Nawab et al., 2018).…”

Nutritional and organoleptic evaluation of functional bread prepared from raw and processed defatted mango kernel flour

“…Fiber rich composition of MSK furnishes low caloric and bulking properties to composite flour and baked goods. MSK has been reported to enhance water and oil retention, emulsion stability, oxidative reactions inhibition, and plasticizing properties (Abdalla, Darwish, Ayad, ; Abdel‐Razik et al, ; Ashoush & Gadallah, ; Legesse & Emire, ; Nawab, Alam, Haq, Lutfi, & Hasnain, in press; Pereira et al, ).…”

In a nutshell: prospects and challenges on coatings for edible kernels

“…53 Indeed, darkening of edible kernels has been followed by decreased color acceptance. 41,54 However, in a recent study, 52 walnuts coated with walnut protein, although darker than an uncoated control, were not less acceptable than the control, whereas walnuts coated with methylcellulose (MC), perceived as lighter in color, had their acceptance impaired. Grosso et al 11 observed that walnuts with coatings based on cellulose derivatives (MC and CMC) were less acceptable than the uncoated ones, whereas a whey protein coating did not affect the product acceptance.…”

“…Dark colors may be associated with deterioration, since kernels usually become darker with storage, which is ascribed to enzymatic oxidation of phenolic compounds . Indeed, darkening of edible kernels has been followed by decreased color acceptance . However, in a recent study, walnuts coated with walnut protein, although darker than an uncoated control, were not less acceptable than the control, whereas walnuts coated with methylcellulose (MC), perceived as lighter in color, had their acceptance impaired.…”