Experimental Study of the Effects of Convective Drying on Some Selected Vegetables

Aim: This work gives the reports on experimental study of the effects of drying on some selected vegetables, namely fluted pumpkin (specimen I), spinach (specimen II), lettuce (specimen III), and waterleaf (specimen IV). Methodology: The vegetable specimens were dried at regulated drying temperatures of 323K, 333K, and 343K, and the percentage amount of water, fat, crude fibre, ash, protein, and carbohydrate, as well as the fungi and bacteria counts in the vegetable specimens was determined at these temperatures. Results: The results revealed that the amount of water in the vegetable specimens reached 0% earlier at the regulated drying temperature of 343K than at the other regulated drying temperatures. The results also indicated that the dried vegetable specimen II has highest fat content of 8.2%, the dried vegetable specimen III has highest crude fibre content of 14.5%, the dried vegetable specimen IV has highest ash content of 18.6%, the dried vegetable specimen I has highest protein content of 30.3%, and the dried vegetable s specimen III has highest carbohydrate content of 42.2% at the regulated drying temperature of 323K. The same trend of results was obtained for the regulated drying temperatures of 333K and 343K. Furthermore, the results showed that at the regulated drying temperature of 323K, the dried vegetable specimen III has the lowest bacteria counts of 4.3 x 107 CFU/g. The trend of result obtained for the regulated drying temperatures of 333K and 343K is similar to that of the 323K. At the regulated drying temperature of 323K, the dried vegetable specimen II has the lowest bacteria counts of 1.7 x 107 CFU/g. The same trend of results was obtained for the regulated drying temperatures of 333K and 343K. Conclusions: Drying has effects on the percentage amount of fat, crude fibre, ash, protein, and carbohydrate in the vegetable specimens. The microbial counts and the fungi counts decrease when the temperature increases. The present work can be applied in food engineering industries, and engineering in agriculture.

Food grade vinegar acts as an effective tool for short-term meat preservation

The study was designed to evaluate the physico-chemical, microbial and sensorial quality of beef incorporated with different levels of vinegar at refrigerated storage (4±1ºC). Fresh beef samples were divided into three different batches i.e. T0 = control (without vinegar), T1 = 5% vinegar and T2 = 10% vinegar. The samples were evaluated for sensory properties (color and flavor), physico-chemical properties (pH, cooking loss, FFA, POV and TBARS) and microbial counts (TVC, TCC and TYMC) on 0, 7 and 14 days of storage at 4ºC. The obtained results showed that addition of different levels of vinegar significantly (p<0.05) influenced on sensory, physico-chemical and microbiological properties compared to control samples. Comparatively better color and flavor were found in T1 and T2 respectively among the treatments (p<0.05). Lower pH was observed in T1 and T2 compared to control treatment. POV, FFA and TBARS values were found better in T1, whereas the other treatments fluctuated slightly. The lowest microbial counts were significantly lower in higher vinegar treated groups along with at different day’s intervals in TVC, TCC and TYMC (p<0.01). It might be stated from the experiment that vinegar is a means of fresh beef preservation for a short time. From this study, it also concluded that 10% vinegar is effective for short term preservation of beef satisfactorily at refrigerated condition.

Comparative Study on Mechanic Workshop Polluted Soil Treated With Lime (Citrus Aurantifolia) Juice, Powder and Inorganic Lime Fertilizer

An assessment of mechanic workshop polluted soil treated with 16.6% lime juice (MSAL), mechanic workshop polluted soil treated with lime powder (MSLP) and mechanic workshop polluted soil treated with inorganic lime fertilizer (MSLF) was conducted for a period of 56 days. The study revealed higher microbial counts in the treated soils compared to mechanic oil free soil (MFS). The total viable bacterial counts observed ranged from 1.6×104 cfu/g to 6.8×104 cfu/g for MSF, 2.2×104 cfu/g – 26.2×104 cfu/g for MSAL, 1.2×104 cfu/g -17.2×104 cfu/g for MSLP and 6.8× 104 cfu/g – 16.0 × 104 cfu/g for MSLF while fungi counts ranged from 2.5×104 cfu/g to 6.4×104 cfu/g for MFS, 4.0×104 cfu/g – 16.4×104 cfu/g for MSAL, 2.6×104 cfu/g -3.8×104 cfu/g for MSLP and 2.1× 104 cfu/g – 4.0 × 104 cfu/g for MSLF. Organisms isolated in the course of the study includes Pseudomonas sp, Staphylococcus sp, Bacillus sp, Micrococcus sp, Escherichia coli, Proteus sp, Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Mucor sp, Saccharomyces sp, and Rhizopus sp. The physicochemical results showed that MSAL had higher moisture content, organic matter content, organic carbon, and nitrate than MSF, MSLP and MSLF. There were significant differences in pH, organic matter content, organic carbon, nitrate and phosphorus at 0.05 probability level, but there was no significant different in the moisture content of the soil undergoing treatment. This is an indication that Lime juice has a greater potential in bioremediation of mechanic workshop polluted soil compared to lime powder and inorganic lime fertilizer.

Assessment of Microbiological Safety and Physicochemical Changes of Grey Oyster Mushroom (Pleurotus sajor-caju) during Storage at 4 °C and 25 °C

This study aimed to evaluate the microbiological and physicochemical properties of grey oyster mushroom during storage (day 0, 3, 6, 9, 12) at 4 °C and 25 °C. The microbial quality and safety analyses were aerobic plate count (APC), yeast and mould count, Escherichia coli count, Bacillus cereus count, and Listeria monocytogenes count, while the physicochemical analyses were pH, water activity, colour, and firmness. Grey oyster mushroom stored at 4 °C showed increasing trend in all microbial counts. A similar trend was observed at 25 °C, but with higher microbial counts except for L. monocytogenes which had a slight reduction from 1.82 ± 1.16 at day 0 to 0.24 ± 0.34 log CFU/g at day 6. The pH of grey oyster mushroom was quite stable when stored at 4 °C (6.42 ± 0.03 at day 0 to 6.46 ± 0.21 at day 12). A decrease in pH was observed when the mushroom was stored at 25 °C (6.42 ± 0.03 at day 0 to 5.38 ± 0.93 at day 6). The Browning Index (BI) increased which indicated by the colour changes on the mushroom cap (front and back) especially at 25 °C. Firmness analysis carried out on mushroom cap and stalk showed a decreasing trend during storage, at which 25 °C displayed prominent loss of firmness in cap and stalk as compared to 4 °C. In conclusion, slower deterioration was observed in grey oyster mushroom stored at 4 °C as compared to 25 °C. This is based on lower microbial counts, and minimal changes in pH, BI, and firmness of grey oyster mushroom.

Chemical, Microbiological and Volatile Composition of Kefir-like Beverages Produced from Red Table Grape Juice in Repeated 24-h Fed-batch Subcultures

The aim of this work was to study the production of kefir-like beverage by fed-batch fermentation of red table grape juice at initial pHs of 3.99 (fermentation A) and 5.99 (fermentation B) with kefir grains during four repeated 24-h fed-batch subcultures. However, all kefir-like beverages (KLB) were characterized by low alcoholic grade (&le; 3.6%, v/v) and lactic and acetic acid concentrations. The beverages obtained from fermentation B had lower concentrations of sugars and higher microbial counts than the KLB obtained in fermentation A. In addition, the KLB from fermentation B were the most aromatic and had the highest contents in alcohols, esters, aldehydes and organic acids compared to the non-fermented juice and KLB from fermentation A. These results indicate the possibility of obtaining red table grapes KLB with their own distinctive aromatic characteristics and a high content in probiotic viable cells, contributing to the valorization of this fruit.

High-Condensed Tannin Diet and Transportation Stress in Goats: Effects on Physiological Responses, Gut Microbial Counts and Meat Quality

Feeding condensed tannin (CT)-containing diets such as sericea lespedeza (Lespedeza cuneata) and reducing stress have been reported to improve meat quality and food safety in goats. In a completely randomized design with split-plot, thirty-six uncastrated male Spanish goats were assigned to 3 dietary treatments (n = 12/treatment): ground ‘Serala’ sericea lespedeza hay (SER), bermudagrass (Cynodon dactylon) hay (BG), or bermudagrass hay—dewormed goats (BG-DW; Control) at 75% of intake, with a corn-based supplementation (25%) for 8 weeks. Prior to slaughter, goats were either transported for 90 min to impose stress or held in pens. Basophil counts were lower (p < 0.01) in the SER group compared to BG or BG-DW groups suggesting a better anti-inflammatory capacity due to polyphenols in the SER diet. Compared to BG-DW group, cortisol level was higher (p < 0.05) and norepinephrine was lower (p < 0.05) in the SER group. The SER group had the lowest aerobic plate counts (APC) in both rumen and rectum (p < 0.01). Longissimus dorsi muscle initial pH was not affected by diet or stress. Feeding sericea hay to goats may have beneficial effects, such as enhanced antioxidant and anti-inflammatory properties during stress and reduced gut microbial counts, without changing meat quality characteristics.

Feed Intake Parameters of Horses Fed Soaked or Steamed Hay and Hygienic Quality of Hay Stored following Treatment

Horses suffering from equine asthma must consume low-dust forage, with soaking and steaming being suitable methods of hay treatment. The impacts of this treated hay’s subsequent storage and effects on the horses’ chewing activity are largely unknown. Meadow hay was soaked (10–15 °C, 15 min) or steamed (100 °C, 60 min). Microbial counts (colony forming units (CFU)) were determined by culture before and after soaking or steaming, and subsequent storage at 10 and 25 °C for 6, 12 and 24 h (three replicates each). Six horses were fed native, soaked and steamed hay, according to a cross-over design, and chewing parameters were measured. Steaming reduced (p < 0.05) typical mold vs. soaking (0 vs. 50 CFU/g) and yeasts vs. native and steamed hay (0 vs. 102 and 90 CFU/g). Storing soaked hay elevated bacteria, mold, and yeasts (p < 0.05). Within the first 60 min of hay intake, the steamed hay and soaked hay were eaten slower (19.5 and 21.5 g dry matter/min, respectively; p < 0.05) and the steamed hay was chewed more intensely (steamed hay: 3537; native: 2622; and soaked: 2521 chewing cycles/kg dry matter, p < 0.05). Steaming particularly improves the hygienic quality of hay. Soaked hay is not stable when stored and is less accepted by horses.

In-Plant Intervention Validation of a Novel Ozone Generation Technology (Bio-Safe) Compared to Lactic Acid in Variety Meats

The objective of this experiment was to compare the antimicrobial efficacy of an aqueous ozone intervention and a lactic acid solution on natural microbiota of variety meats in a commercial beef processing plant. EZ-Reach™ swabs were used to collect 100 cm2 area samples before and after ozone and lactic acid intervention application for three different offals (head, heart, and liver). Each repetition included 54 samples per variety meat and antimicrobial for a total of 162 samples per repetition. Enumeration of total aerobic bacteria (APC) and Escherichia coli (EC) was performed on each sample. Microbial counts for both microorganisms evaluated were significantly reduced (p < 0.001) after lactic acid immersion (2–5%) and ozone intervention for all variety meats, with the exception of ozone intervention in EC counts of the heart samples. APC after lactic acid intervention was reduced on average by 1.73, 1.66, and 1.50 Log CFU/sample in the head, heart, and liver, respectively, while after ozone intervention, counts were reduced on average by 1.66, 0.52, and 1.20 Log CFU/sample. EC counts after lactic acid intervention were reduced on average by 0.96, 0.79, and 1.00 Log CFU/sample in the head, heart, and liver, respectively, while after ozone intervention, counts were reduced on average by 0.75, 0.62, and 1.25 Log CFU/sample. The aqueous ozone antimicrobial scheme proved to be a promising intervention for the in-plant reduction of indicator levels in variety meats, specifically heads, hearts, and livers.