Physicochemical properties of saponin containing Acanthophyllum laxiusculum extract: example application in foam stability and qualitative parameters for malt beverage industry.

Aqueous Extract of Acanthophyllum laxiusculum root (AE) exhibited remarkable foaming profile, emulsification properties and antifungal activity due to the presence of high concentration of total saponins. Total phenolic compounds, another main component, accounted for the AE antioxidant activity. Spray drying of AE, as a thermal process, did not affect the foaming indices of A. laxiusculum Spray-dried Extract (SE) and is a recommended alternate for convenient application in food industry. Addition of SE to the malt extract at accepted levels of total saponin daily intake (below 50 mg/kg) showed positive attribution of malt and carbonation on the foaming quality of SE. Meanwhile, antioxidant activity of commercial malt beverage was enhanced by addition of phenolic compounds containing SE. The 20-60% antifungal inhibitory ratio of the SE developed here is within the applied range of total saponin that supports its application to inhibit the growth of Saccharomyces cerevisiae after malt beverage production. The bitter taste of SE was not sensed in malt beverage at 30 mg/kg total saponin content and suggested A. laxiusculum root extract as a natural additive in malt industry.

Effect of washing, soaking and pH in combination with ultrasound on enzymatic rancidity, phytic acid, heavy metals and coliforms of rice bran.

Simultaneous reduction in activity of fat destabilizing enzymes (lipase and lipoxygenase), contaminants heavy metals (As, Cd, Pb, and Hg), antinutrient phytic acid and hazardous coliforms in rice bran was investigated. Application of washing, soaking the washed sample at different pH values (2, 6 and 9) alone or in combination with ultrasonication were examined. While washing was beneficial, its low efficiency acquired further treatment, which was prevailed by application of acidic pH and ultrasound (28 kHz) treatments. Free fatty acids and peroxide value, as indicators of enzymes activity, implied the effectiveness of treatments with adverse impact of sonication on peroxide value. Remarkably, reduction of dominant heavy metals (As, Pb and Zn) and phytic acid were synergistically facilitated by sonication. Coliforms growth was inhibited at pH 2 even at the absence of ultrasonic treatment. Evidently, combination of acidic pH and ultrasound is a practical approach to improve rice bran stability and safety.

A review on inactivation methods of Toxoplasma gondii in foods.

Toxoplasmosis is an infection caused by Toxoplasma gondii, a widespread zoonotic protozoan which poses a great threat to human health and economic well-being worldwide. It is usually acquired by ingestion of water contaminated with oocysts from the feces of infected cats or by the ingestion of raw or undercooked foodstuff containing tissue cysts. The oocyst can contaminate irrigation water and fresh edible produce. It is estimated that approximately one-third of the human population worldwide harbor this parasite. Infection with T. gondii is an important cause of diseases of the central nervous system and the eye in immunocompromised and immunocompetent individuals. The purpose of this study was to evaluate the efficacy and applicability of thermal (heating, cooking, freezing and low temperature), non-thermal (high pressure processing, ionizing irradiation and curing) and chemical and biochemical (disinfection, essential oils and biochemical methods such as enzymes, nanoparticles, antibiotics and immune response) treatments for the inactivation, inhabitation or to kill T. gondii in foodstuff intended for public consumption and under experimental conditions.

Sensory, digestion, and texture quality of commercial gluten-free bread: Impact of broken rice flour type.

This research investigated the effects of two varieties of broken rice (Khouzestan and Lenjan) from warm and dry regions, and two (Hashemi and Tarom) from mild and humid regions on different parameters including dough rheology, digestibility, and quality (color, specific volume, textural properties, and sensorial properties) of a commercial gluten-free bread (GFB). Furthermore, the rice varieties' hydration properties, gelatinization temperatures, and starch-granule morphology were assessed. Significant differences were observed in the varieties' proximate composition and hydration properties from both climate zones. The granules' average size was 3.17-4.9 µm. The specific volume of the breads showed no correlation with either the damaged starch content or the amylose content, but had a significant negative correlation with hardness (r = -.923, p < .05). The crumb hardness of bread was positively correlated with water-binding capacity and was affected by elastic modulus of dough. Results of predicted glycemic index were in accordance with total carbohydrates. Khouzestan received the highest score in sensory evaluation test. Based on the outcomes for bread-quality attributes, Khouzestan from the warm and dry region, which is a cheaper rice variety in Iran, was the most appropriate variety for GFB production. Moreover, it was determined that the rice varieties currently used in commercial manufacture of gluten-free bread do not necessarily yield the highest-quality bread. PRACTICAL APPLICATIONS: Gluten-free breads (GFBs) are generally used by Coeliac patients. In comparison to wheat bread, the quality of GFBs is lower. Rice is one of the main ingredients of GFBs' formulation, thence by determining the quality-related features of the rice, improvement in the final product could be achieved. In addition, by implementing the cheap and the broken rice variety, the price of the final product could be decreased and be more affordable for the patients.

Characterization of lycopene hydrocolloidal structure induced by tomato processing.

Tomato juice and paste are special type of dispersions, composed of suspended particles (pulp) dispersed in a colloidal liquid medium (serum). The bright red appearance of soluble solid separated by high speed centrifugation denoted the presence of lycopene in this fraction. Since lycopene is a hydrophobic compound it is not expected to appear in the water soluble fraction. HPLC analysis indicated presence of substantial amount of lycopene in soluble fraction which was confirmed by the appearance of lycopene crystals when observed under Transmission Electron Microscope (TEM). Considerable amount of pectin in the soluble fraction led to hypothesis that pectin facilitated the formation of hydrocolloidal system of suspended lycopene during processing. Enzyme treatment confirmed this hypothesis when pectinase effectively disrupted colloidal system and precipitated lycopene. Necessity of the divalent ions to retain the suspension signified the electrostatic interactions in the matrix surrounding lycopene crystals.

Viability of probiotic bacteria and some chemical and sensory characteristics in cornelian cherry juice during cold storage

Background: Increased popularity of vegetarianism, lactose intolerance, and the high cholesterol content in dairy products, are all factors that have recently increased the demand for nondairy probiotic products. The objective of this study is to evaluate the effect of refrigeration on the viability of probiotics and asses some of the chemical and sensory characteristics in cornelian cherry juice. Results: The Iranian native probiotic strain (L. casei T4) showed greater viability compared to industrial types (viable count of 8.67 log cfu/mL versus <6.0 log cfu/mL at d 28). However, this most tolerant Iranian strain, could not withstand the conditions of 'Natural juice' at pH 2.6 for more than 7 d. Following a pH adjusted treatment (to pH ~3.5), the viability of the strain was improved to 28 d with some evidence of increased growth of the probiotic. However, the level of antioxidant activity, anthocyanin and phenolic compounds, revealed a slight decrease during cold storage. The changes in the chemical profile of the sample containing L. casei T4 indicated fermentation activity during cold storage. Sensory evaluation results showed significant differences between samples containing L. casei TD4 and other samples in taste, odor and overall acceptance in a complimentary way. Conclusion: The results showed that low pH and presence of inhibitor phenolic compounds of cornelian cherry juice have negative effect on viability of probiotics, especially industrial strains during refrigerated storage.

Comparison of two methods for determination of tomato paste solids: vacuum oven versus microwave oven.

Two analytical procedures used to determine total, soluble, and insoluble solids in tomato paste were evaluated. The microwave oven (MO) method was compared to the vacuum oven (VO) method. The VO method is tedious and measured the three solids fractions in the paste directly, while the MO method measured the total solids directly but used an equation to calculate the water-soluble and -insoluble solids. The MO method was faster and less labor-intensive, and yielded small but statistically significant higher values for total and insoluble solids and lower statistically significant values for soluble solids.