Cassava Starch Coating and Citric Acid to Preserve Quality Parameters of Fresh-Cut “Tommy Atkins” Mango

Abstract: Combination of citric acid dipping (5 g/L) and cassava starch coating (10 g/L), with and without glycerol (10 g/L), was studied to verify the effectiveness of these treatments to inhibit enzymatic browning, to reduce respiration rate, and to preserve quality parameters of “Tommy Atkins” fresh-cut mangoes during storage at 5 °C. Color characteristics (L* and C*), mechanical properties (stress at failure), weight loss, β-carotene content, sensory acceptance, and microbial growth of fruits were evaluated during 15 d. The respiration rate of fruit subjected to the treatments was also analyzed. Nontreated fresh-cut mango was used as a control sample. Cassava starch edible coatings and citric acid dipping promoted a decrease in respiration rate of mango slices, with values up to 41% lower than the control fruit. This treatment also promoted better preservation of texture and color characteristics of mangoes and delayed carotenoid formation and browning reactions during storage. Moreover, the treated fruit showed great sensory acceptance by consumers throughout the whole storage period. However, the use of glycerol in the coating formulation was not efficient in the maintenance of quality parameters of fresh-cut mangoes, promoting a higher weight loss of samples, impairing fruit texture characteristics, increasing carotenogenesis, and favoring microbial growth during storage. Practical Application: Consumer demand for tropical fresh-cut products is increasing rapidly in the world market. Fresh-cut mangoes are appreciated world-wide for its exotic flavor. However, its shelf life is limited by changes in color, texture, appearance, off-flavors and microbial growth. The edible coatings act as gas and water vapor barrier, extending the storage time of fresh-cut fruit and vegetables. Thus, cassava starch is an alternative to preserve minimally processed mangoes and the quality parameters of fresh fruit. The information of this work is useful for the fresh-cut produce industry to increase shelf life of fresh-cut mangoes, which can be considered an alternative to fast food and other ready-to-eat products, attending the demand for healthy and convenient foodstuffs.     

Microbial survival curves — the reality of flat “shoulders” and absolute thermal death times

Occasionally, experimental survival curves of micro-organisms exposed to a lethal agent have a flat region and traditionally it has been interpreted as evidence of the existence of a “shoulder”. However, if the survival curve is considered the cumulative distribution of lethal events, which reflects a spectrum of resistances, or sensitivities, then when the distribution's mean, or mode, is large relative to its spread, a region resembling a “shoulder” will be observed irrespective of whether the distribution is symmetric or skewed. Computer simulated survival curves generated with the Fermi and Weibull distributions as models demonstrate that the shape of the survival curve alone is, therefore, insufficient to confirm any specific inactivation mechanisms at the cellular and molecular level, although it can refute the existence of some. Microbial mortality has also been assumed to be a process following an exponential decay and hence that a certain degree of survival is inevitable. It is not inconceivable, however, that there can be an absolute thermal death time if the survivors are being progressively weakened by a prolonged exposure to the lethal agent. This testable possibility is demonstrated with simulated survival curves generated with two mathematical models.     

Effects of Chitosan,Calcium Chloride,and Pullulan Coating Treatments on Antioxidant Activity in Pear cv. “Huang guan” During Storage

Effects of different calcium chloride, chitosan and pullulan coating treatments on antioxidant activity of “Huang guan” pears (Pyrus pyrifolia Nakai) during storage have been studied. Total phenolic content, phenolic composition, total flavonoid content, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities, and antioxidant activity (1,1-diphenyl-2-picrylhydrazyl (DPPH), 2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant potential (FRAP)) were determined in peel and pulp tissues over 210 days. Coating treatments slowed decrease of total phenolic and flavonoid contents, chlorogenic acid, arbutin, catechin and caffeic acid, SOD and CAT activities, and total antioxidant activity. However, POD activity was inhibited. The antioxidant content in the peel was higher than in the pulp. Of the coatings, chitosan was the most effective, but overall, all coatings may be useful to extend shelf-life, maintain quality and control decline of antioxidant activity in pear.     

Potency of Combination of Palm Kernel Meal and Katuk Leaf Powder to Improve the Production Performance of Peranakan Etawa (PE) Goat: Toward a Strategy for Quality Control of Meat Using “CGE” Concept

This research was aimed to study the potency of suplementation of a combination of palm kernel meal and katuk leaf powder (Sauropus androgynus L. Merr) to the production performance in PE goat. The final target of this study is to develop a strategy for quality control of meat using a “clean, green, and ethical” (CGE) concept of technology. This study were used 20 male PE goat at aged of + 1.5 years and weight of 15-20 kg. The result showed that the suplementation of BISKAT was induced a higher level of testosterone in male PE goat. In conclusion, testosterone levels of PE goat tends to increase after given a combination of palm kernel meal and katuk leaf powder. Therefore, the technique used in this research might direct us to to develop a strategy for quality control of meat product in livestock using a “clean, green, and ethical” (CGE) concept of technology in the future.