Undesirable Enzymatic Browning in Crustaceans: Causative Effects and Its Inhibition by Phenolic Compounds

Undesirable enzymatic browning mediated by polyphenol oxidase (E.C. 1.14.18.1) on the surface of seafood from crustaceans have been a great concern to food processors, causing quality losses of seafood products. Seafoods especially from crustaceans are worldwide consumed due to their delicacy and nutritional value. However, black spot formation (melanosis) is the major problem occurring in crustaceans during postmortem handling and refrigerated storage induce deleterious changes in organoleptic properties and, therefore, decreases commercial value. Polyphenoloxidase (PPO), the copper-containing metalloprotein involved in oxidation of phenol to quinone is the major biochemical reaction of melanosis formation. This enzymatic mechanism causes unappealing blackening in postharvest crustaceans. To alleviate the melanosis formation in crustaceans, use of phenolic compounds from plant extract can serve as antimelanotics and appears to be a good alternative to the conventional sulfites which are associated with health-related disorders. In this review, we focuses on the unique features about the structure, distribution, and properties of PPO as well as mechanism of melanosis formation and provide a comprehensive deeper insight on the factors affecting melanosis formation and its inhibition by various antimelanotics including newly discovered plant phenolic compounds.     

Smart packaging: sensors for monitoring of food quality and safety

The development of chemical sensors and biosensors over several decades has been investigated resulting in novel and very interesting sensor devices with great promise for many areas of applications including food technology. The incorporation of such sensors into the food packaging technology has resulted what we call smart or intelligent packaging. These are truly integrated and interdisciplinary systems that invoke expertise from the fields of chemistry, biochemistry, physics and electronics as well as food science and technology. Smart packaging utilises chemical sensor or biosensor to monitor the quality & safety of food from the producers to the costumers. This technology can result in a variety of sensor designs that are suitable for monitoring of food quality and safety, such as freshness, pathogens, leakage, carbon dioxide, oxygen, pH, time or temperature. Thus, this technology is needed as on-line quality control and safety in term of consumers, authorities and food producers, and has great potential in the development of new sensing systems integrated in the food packaging, which are beyond the existing conventional technologies, like control of weight, volume, colour and appearance.     

Effect of transglutaminase on the functional properties of GDL (glucono‐delta‐lactone) cold‐set soybean glycinin gel

Cold‐set soybean glycinin gel was prepared by cross‐linking of soybean glycinin (non‐preheated and preheated) at pH 8.0 and 50 °C using transglutaminase (TG), followed by cold‐set acidification using glucono‐δ‐lactone (GDL). Dynamic oscillatory rheological measurements (both under non‐preheat and preheat conditions) showed that there was a substantial increase in the elastic (G′) and viscous (G″) moduli of enzyme treated gels. The moduli also showed similar frequency dependence. The yield strains of enzyme treated gels were clearly higher than that of the gels without enzyme treatment. Texture profile analysis indicated that preheat and enzyme treatments have beneficial effect on hardness, fracturability and gumminess of gels. Thermal and enzyme treatments have synergetic effect to improve the strength of gels, which is also consistent with the results of rheological measurements. These results demonstrated that heat treatment followed by TG treatment and GDL acidification improved the functional properties of soybean glycinin cold‐set gel.     

Ergogenic Attributes of Young and Mature Coconut (Cocos nucifera L.) Water Based on Physical Properties,Sugars and Electrolytes Contents

The present work aimed to compare the main ergogenic attributes of two commercialized stages (young and mature) of coconut water (CW) obtained from four coconut varieties. The changes of electrolytes and sugars in CW upon maturation were quantified by inductively coupled plasma mass spectrophotometer and high-performance liquid chromatography, respectively. Based on the electrolyte profiling, potassium yielded the highest amount (ranging from 237.41 to 361.20 mg/100 mL) followed by sodium, magnesium, calcium, iron, manganese, copper, selenium, and zinc across all the maturity stages tested. For sugars, there were lower amounts of fructose and glucose, but a higher amount of sucrose with the maturation of the fruits. In conclusion, the amount of beneficial nutrients in the form of sugars and minerals was higher than that of young CW, and the ergogenic attributes of mature CW especially from MATAG variety (M-MATAG) were the best to be exploited further in the development of natural energy drinks.     

Effect of heat moisture treatment on resistant starch content among carbohydrate sources: a meta-analysis

Resistant starch (RS) can be generated through heat moisture treatment (HMT). The HMT was conducted by modifying starch using different ratio of moisture content, high temperature and heating time. A number of studies showed that the effects of HMT on RS contents in cereals, pulses, tubers and fruits were inconsistent. This study aimed to analyse the impact of HMT on RS level in various carbohydrate sources through a meta-analysis approach. Study selection was conducted with the PRISMA method. There were 21 relevant studies and 67 data used for meta-analysis. The database was analysed by using Hedges’ d. The results showed that there was a significant impact of HMT on RS level of cereals, especially wheat. The highest increase in RS levels for various carbohydrate sources in starch was influenced by the interaction of treatment between water content at 15 ≤ x < 25%, heating time at 0.25 < x ≤ 6 h and temperature at 120 ≤ x ≤ 130 °C.     

Effect of short-term storage on phenolic content,o-diphenolase and peroxidase activities of cut yam tubers (Dioscorea sp)

The effect of short-term storage on the protein, phosphorus and phenolic content as well as peroxidase and o-diphenolase activities of cut, harvested Jamaican yam (Dioscorea sp) tubers (D rotundata. D alata and D cayenensis) was studied. There was an initial increase in the total phenolic content up to the third week of storage followed by a gradual decrease to the sixth week. Phenolic content was found to be highest in D cayenensis followed by D rotundata and D alata. The activities of peroxidase (EC 1. 11. 1. 7) and o-diphenolase (EC 1. 10.3.1) increased steadily up to the third week of storage and thereafter decreased to the fifth week. The intensity and rapidity of browning in tubers when cut, correlated very closely with the tuber o-diphenolase and phenolic content levels while the onset of rotting correlated with the peroxidase activity levels in the species studied.     

Antioxidants and antiradicals in almond hull and shell (Amygdalus communis L.) as a function of genotype

To compare the antioxidant and antiradical activity of Amygdalus communis L. hulls and shells phenolic extracts in different genotypes, 18 A. communis L. genotypes were selected from those in Qooshchi, Qalgachi, Qovarchin Qale, Najaf Abad, Jamal Abad, Kahriz, Sfahlan of West and East Azerbayjan provinces of Iran in 2007. The fruits of these almonds were collected, their hulls and shells dried, ground and then methanolic extracts prepared from these hulls and shells. Total phenolic content was determined using the Folin–Ciocalteu (F–C) method. The extracts’ reducing power and scavenging capacity for radical nitrite, hydrogen peroxide and superoxide were evaluated. Significant differences were found in phenolic content of hulls and shells among various genotypes, radical scavenging capacity percentage varied significantly among genotypes and their hulls and shells. S₃-7 genotype with the highest phenolic content and antioxidant activity in its hulls represents a valuable genotype for procuring antioxidant phenolic compounds.     

Calcified right ventricular fibroma causing outflow obstruction. Report of a case with successful excision

A 5-year-old boy with clinical findings of pulmonic stenosis was found to have a large calcified mass in the right ventricular outflow region and a gradient of 120 mm Hg between the right ventricle and the pulmonary artery. At surgery, an ovalshaped tumor attached to the interventricular septum and obstructing the right ventricular outflow tract was removed. The child survived and is doing well. Histologically, the tumor had the characteristics of fibroma. A hemodynamic study three months after surgery showed almost complete abolishment of the gradient. To our knowledge this is the fifth reported case of calcified right ventricular fibroma with successful operation. In childhood intracardiac calcifications, together with obstruction, are highly suggestive of this lesion.