Strawberry fruits have a short shelf life after harvesting due the physiological factors that enhances ripening such as respiration and transpiration. Sensory properties including color, texture, odor, and flavor are the main factors that makes fresh produce appealing to consumers, and they change very rapidly upon harvest. For this reason, quality preservation is essential during post-harvest handling and storage of strawberry fruits. Quality deterioration rates are higher in strawberry fruit cuts due to the mechanical damage and the loss of their natural protective barriers, resulting in an increase in moisture loss, respiration rates, and the deterioration of their sensory properties. The effect of a sodium alginate-calcium chloride edible coating on quality preservation and shelf life extension of strawberry cut fruits stored at 4 °C was studied. Control samples had mold growth initiated after one week of storage at 4 °C, while the coated fruit samples had a mold free shelf life extension for up to 15 days. The sodium alginate-calcium chloride edible coating was effective in reducing respiration and transpiration rates and delayed the increase of the pH and soluble solid content. Furthermore, the coating delayed surface mold growth for up to 15 days and preserved the sensory properties of the cut fruits such as color and texture.

Osmotic dehydration is a pre-treatment given prior to finish drying or freezing preservation to improve quality and/or minimize the damaging effects on quality parameters, by partially reducing the moisture content of the sample. Pineapple titbits were partially dried using microwave assisted osmotic dehydration under continuous flow medium spray condition (MWODS) and then frozen with or without a sodium alginate–calcium chloride-based edible coating. The effects of MWODS pre-treatment and edible coating on the quality parameters of pineapple titbits frozen and stored at −20 °C for 10 and 50 days were evaluated after thawing. Both treatments (MWODS and alginate) resulted in superior quality products as compared to the control sample. MWODS, with its advantages over the conventional osmotic dehydration (COD) of rapid and higher moisture removal (16% in 10 min vs. 4 h in COD), while limiting solids gain (2.5% MWODS vs. 4.5% in COD), resulted in improved quality over the control during the frozen storage. The sodium alginate–calcium chloride edible coating treatment further reduced the drip loss in MW-osmo-dehydro-frozen pineapple titbits, possibly due to the effect of the calcium cross linked firming of the fruit texture. Both resulted in enhanced appearance, color and textural properties.

Extrusion cooking is broadly used in the food industry due to its easiness and simplicity. In this study a twin-screw extruder is applied at 150 rpm and 24–28 °C for the production of a nutritionally enriched extruded matrix, where hypo-allergenic rice protein (RP) and pea protein (PP) were used in the entrapment of natural antioxidant blueberry powder. The higher-moisture-content extrusion (40% MC) used with protein mixture (75 PP:25 RP) reduced the output temperature from 61.97 °C to 55 °C, the expansion ratio from 1.26 to 1, and the rehydration ratio from 78.70% to 31.90%, when compared with low-moisture-content extrusion used with RP samples (25% MC). Combining RP and PP showed also an enhancement in the textural properties of the extruded samples where firmness and toughness increased to 1503 (g) and 1822 (g.s), respectively, and preserved the anthocyanin content and antioxidant activity during extrusion processing and subsequent finish air drying. Moreover, the addition of maltodextrin in low concentration (5%) enhanced the antioxidant activity and anthocyanin retention (by 98.59% in mixture samples after extrusion and 92.13% after drying) and improved the appearance and sensory properties of the extruded matrices including firmness, toughness, and the color of the added blueberry powder.