Effect of Packaging Material on Moisture Migration and Textural Attributes of Bread During Storage

Bread as a commodity is included in the special inventory of Defence Forces, particularly as a morning or evening snack item. The present investigation pertains to the studies on the effect of various packaging materials, e.g. metalized polyester (MP-99.8 µm), low-density polyethylene with lower thickness (LDPE-1-78.33 µm), multi-layer flexible pouches (MLFP-106.2 µm), low-density polyethylene with higher thickness (LDPE-2-125.12 µm), and paper foil polyethylene (PFP-124.6 µm) on textural attributes of bread. Textural properties were significantly influenced by the change in moisture content which was clearly shifted from crumb to crust to the extent varying from -25.89% to +24.90% in LDPE-2; -29.11% to +29.77% in MP; -22.22% to +21.11%; in MLFP; -19.46% to +19.67% in PFP; -20.42% to +20.55% in LDPE-1 at the end of its expected shelf-life i.e. five days. Though overall bread moisture content was not much affected in PFP and MP, the marked difference was primarily observed in the case of bread packed in LDPE-2, LDPE-1, and MLFP. This difference may be attributed to the thickness and permeable properties of the packaging material used for the study. The hardness and resilience of samples depicted opposite trends, respectively, during their storage. The current study gives insight into physicochemical changes occurring in the bread system when  variety commonly practiced packaging materials is used and a perspective strategy for its extended life during varied field conditions.

Can volatile organic metabolites be used to simultaneously assess microbial and mite contamination level in cereal grains and coffee beans?

A novel approach based on headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-ToFMS) was developed for the simultaneous screening of microbial and mite contamination level in cereals and coffee beans. The proposed approach emerges as a powerful tool for the rapid assessment of the microbial contamination level (ca. 70 min versus ca. 72 to 120 h for bacteria and fungi, respectively, using conventional plate counts), and mite contamination (ca. 70 min versus ca. 24 h). A full-factorial design was performed for optimization of the SPME experimental parameters. The methodology was applied to three types of rice (rough, brown, and white rice), oat, wheat, and green and roasted coffee beans. Simultaneously, microbiological analysis of the samples (total aerobic microorganisms, moulds, and yeasts) was performed by conventional plate counts. A set of 54 volatile markers was selected among all the compounds detected by GC×GC-ToFMS. Principal Component Analysis (PCA) was applied in order to establish a relationship between potential volatile markers and the level of microbial contamination. Methylbenzene, 3-octanone, 2-nonanone, 2-methyl-3-pentanol, 1-octen-3-ol, and 2-hexanone were associated to samples with higher microbial contamination level, especially in rough rice. Moreover, oat exhibited a high GC peak area of 2-hydroxy-6-methylbenzaldehyde, a sexual and alarm pheromone for adult mites, which in the other matrices appeared as a trace component. The number of mites detected in oat grains was correlated to the GC peak area of the pheromone. The HS-SPME/GC×GC-ToFMS methodology can be regarded as the basis for the development of a rapid and versatile method that can be applied in industry to the simultaneous assessment the level of microbiological contamination and for detection of mites in cereals grains and coffee beans

Organic Versus Conventional – a Comparative Study on Quality and Nutritive Value of Selected Vegetable Crops of Southern India

Vegetables are defined as edible plant parts generally consumed raw or cooked with a main dish, in a mixed dish, as an appetizer or as a salad. Food safety aspects related to microbial quality (total plate count, yeast and mold and food borne pathogens) and toxic residue (heavy metals) and mineral content were investigated for vegetables such as green leafy vegetable, salad vegetables, sprouts, brinjal, green chilies and French beans collected from organic and conventional outlets from Mysore region, Karnataka, India. Microbial analysis was carried out using standard procedures and mminerals (Ca, K, Fe, Cu, Mg, Mn and Zn) and heavy metals (Cd and Pb) were determined. Significant variations (p&gt;0.05) were observed for microbial quality among organic and conventional vegetables. Mineral and vitamin C content were also significantly higher (p&gt;0.01) in organic samples. Heavy metal contamination for lead and cadmium tested positive for conventional samples while organic samples tested negative. The variables that contributed most for the variability were heavy metal contamination, mineral and vitamin C content. Organically grown vegetables were free from heavy metals and safe for consumption, as well as they are rich in mineral and vitamin C content in comparison to conventional samples.&#x0D; SAARC J. Agri., 18(1): 99-116 (2020)</jats:p