Efficacy of pink guava pulp as an antioxidant in raw pork emulsion

Addition of Natural Extracts with Antioxidant Function to Preserve the Quality of Meat Products

Antioxidants are used to prevent oxidation reactions and inhibit the development of unwanted sensory characteristics that decrease the nutritional quality, acceptance, and shelf-life of processed meat products, improving their stability. Synthetic antioxidants, although efficient, are related to the development of diseases because they present toxic and carcinogenic effects. Thus, researchers and the meat industry are studying natural alternatives to synthetic antioxidants to be used in meat products, thus meeting the demand of consumers who seek foods without additives in their composition. These natural extracts have compounds that exert antioxidant activity in different meat products by different mechanisms. Thus, this review work aimed to gather studies that applied natural extracts derived from different plant sources as possible antioxidants in meat products and their action in preserving the quality of these products.

Construction of Genetic Linkage Map and Mapping QTL Specific to Leaf Anthocyanin Colouration in Mapping Population 'Allahabad Safeda' × 'Purple Guava (Local)' of Guava (Psidium guajava L.)

In the present investigation, F1 hybrids were developed in guava (Psidium guajava L.) by crossing high leaf-anthocyanin reflective-index (ARI1) content cultivars purple guava (local) 'PG', 'CISH G-1' and low leaf-ARI1 content cultivar Seedless 'SL' with Allahabad Safeda 'AS'. On the basis of phenotypic observations, high ARI1 content was observed in the cross 'AS' × 'PG' (0.214). Further, an SSR-markers-based genetic linkage map was developed from a mapping population of 238 F1 individuals derived from cross 'AS' × 'PG'. The linkage map comprised 11 linkage groups (LGs), spanning 1601.7 cM with an average marker interval distance of 29.61 cM between adjacent markers. Five anthocyanin-content related gene-specific markers from apple were tested for parental polymorphism in the genotypes 'AS' and 'PG'. Subsequently, a marker, viz., 'MdMYB10F1', revealed a strong association with leaf anthocyanin content in the guava mapping population. QTL (qARI-6-1) on LG6 explains much of the variation (PVE = 11.51% with LOD = 4.67) in levels of leaf anthocyanin colouration. This is the first report of amplification/utilization of apple anthocyanin-related genes in guava. The genotypic data generated from the genetic map can be further exploited in future for the enrichment of linkage maps and for identification of complex quantitative trait loci (QTLs) governing economically important fruit quality traits in guava.

Optimisation of extraction protocol for Carica papaya L. to obtain phenolic rich phyto-extract with prospective application in chevon emulsion system

The present study optimized the extraction protocol conditions to obtain the antioxidant-rich bioactive extracts from Carica papaya L. (Papaya) leaves. A Box and Behnken Design (BBD) consisting of three different extracting variables viz. extracting temperature (60-70 °C), time (10-20 min) and solvent concentration (55-65%) was used. Antioxidant efficacy was recorded by evaluating four responses viz. ABTS, DPPH, SASA and total phenolic contents. The optimized model predicted, solvent concentration of 60% with extraction time of 15 min and extracting temperature of 65 °C with bioactive-rich antioxidants having highest total phenolic activity. The efficacy of obtained bioactive-rich papaya leaves extracts (PLE) were subjected for in-vivo evaluation in chevon emulsion added with the level of T-1 (0.10%); T-2 (0.25%); T-3 (0.50%) and control (without extract) stored under refrigeration (4 ± 1 °C) for 9 days by evaluating various physicochemical, microbiological, sensory quality characteristics. The pH was significantly higher for control than all treatments and water activity (a_w) showed decreasing trend throughout storage period. Oxidation efficiency values showed an increasing drift during storage period, irrespective of added level of PLE, showing lowest oxidation in samples treated with 0.5% PLE. Sensory panellists awarded comparatively higher scores to all PLE treatments than control. Microbiological quality of emulsion incorporated with different levels of papaya leaves extract successfully improved and was lower in 0.5% PLE treated samples. It was concluded that extraction of bioactive antioxidants from Carica papaya L. leaves improved by optimising extraction parameters using RSM. Carica papaya L. leaves extracts have proven prospects as natural anti-oxidants in chevon emulsion as a meat emulsion system.

Oxidative stability of pork emulsion containing tomato products and pink guava pulp during refrigerated aerobic storage

Lipid oxidation-induced quality problems can be minimized with the use of natural antioxidants. Antioxidant potential of tomato puree (10 %; T-1), tomato pulp (12.5 %; T-2), lyophilized tomato peel (6 %; T-3), and pink guava pulp (10 %; T-4) was evaluated in raw pork emulsion during refrigerated storage for 9 days under aerobic packaging. The lycopene and β-carotene content varied in pork emulsion as T-3 > T-1 > T-2 > T-4 and decreased (P < 0.05) during storage. The surface redness (a* value) increased (P < 0.05) with the incorporation of tomato products and pink guava pulp. Furthermore, metmyoglobin formation and lipid oxidation were lower (P < 0.05) in tomato- and guava-treated emulsions than in control. Overall, incorporation of tomato products and pink guava pulp improved the visual colour and odour scores of raw pork emulsion. These results indicated that tomato products and guava pulp can be utilized as sources of natural antioxidants in raw pork products to minimize lipid oxidation, off-odour development, and surface discolouration.