-
Using natural preservatives in ghee and fat-rich products has great economic importance as it can minimize adverse effects on human health and improve the marketing prospects of products. The present study aimed to use lemon (Citrus lemon L.) and mandarin (Citrus reticulata L.) peel extracts as natural preservatives instead of synthetic antioxidants of butylated hydroxyanisole (BHA) to retard the oxidation of ghee during accelerated storage at various temperatures. Antioxidant activities of lemon peel extracts (LPE), mandarin peel extracts (MPE) and BHA in ghee samples stored at different storage temperatures (T1: 5±2°C, T2: 25±2°C, T3: 60±2°C) were evaluated during the storage period (0, 20 and 40 days). The peroxide value (PV), free fatty acids (FFA), and antioxidant activity of the ghee samples were analyzed and compared with control sample (without additives). The PV and FFA content were significantly higher in the control sample than in the ghee samples treated with BHA, LPE, and MPE at all storage temperatures and during the storage period. All treatments led to a reduction in the PV and FFA content, but LPE had the most significant effect, followed by BHA and MPE, respectively. Antioxidant activity was evaluated by the 3-ethyl benzthiazoline-6-sulphonic acid (ABTS) assay; LPE had the highest antioxidant activity, followed by MPE. Compared to the control sample: BHA, LPE and MPE led to a higher reduction in the PV and FFA content of ghee samples at all storage temperatures and periods owing to their antioxidant activities. Results of incorporated samples showed that using LPE (0.1%) prevented the development of PV and FFA content of ghee samples less than using BHA (0.2%). The present study suggests that LPE (0.1%) could be used as a good natural antioxidant preservative to reduce oxidative deterioration of ghee and fat-rich products.
A total of 243 samples of potato chips (135 samples) and ice cream (108 samples) were collected from different regions and brands in Assiut Governorate -Egypt during May to July, 2011.Iron, manganese, copper, aluminum, nickel, lead, cadmium, selenium and arsenic were determined in samples using atomic absorption spectrophotometer.Results revealed no significant differences (P≤0.01)among regions in most ice cream and potato chips samples.The mean concentration of Lead, cadmium, copper, arsenic (potato chips) and nickel (ice cream) were exceeded than the legal limits established by the Egyptian and Codex standards.
Psyllium husk is a bioactive source that provides health benefits and is new best possible use in the dairy industry as a texture enhancer for its hydrochloride properties. The current study focuses on the optimization of a suitable amount of psyllium husk powder (PHP) with whole milk powder (WMP) to produce bioactive probiotic yoghurt and keep it stable during the storage period. The different levels of PHP (0, 0.5, 1.0, and 1.5 % w/w) with WMP were used to prepare the bioactive probiotic yoghurt as a functional food. We made four different mixtures and tested them for their chemical makeup (pH, titratable acidity, moisture, total solids, ash, fat, and protein), colour (L*, a*, b*, and C*), ability to hold water (WHC), and how they tasted after 1, 7, and 14 days at 5°C. The PHP probiotic yoghurt showed a significant decrease (p < 0.05) in pH, protein, and fat. While titratable acidity and ash contents were increased compared with the control. Also, the texture profile, like adhesive and hardiness, had better flow properties and more WHC than the control. Additionally, the color parameter showed an increase in a*, b*, and C* values and a decrease in the L* value. The sensory evaluators preferred the 1% PHP samples. The current study found that samples fortified with 1% PHP improved the physicochemical, texture, and sensory properties of probiotic yoghurt and maintained probiotic yoghurt structure during storage compared with the control. Probiotic yoghurt prepared from PHP has provided new dairy industrial applications.
Pumpkin (Cucurbita sp.) is a natural ingredient with health benefits because of its rich contents of vitamins (A, B1, B2 and C) minerals (K, P, Mg, Fe and Se), β‐carotene, pectin and dietary fiber. In this study, low-fat probiotic yogurt samples enriched with pumpkin powder (1% YPP1, 3% YPP2 and 5% YPP3) and inulin (1%) were produced to achieve the potential health benefits of pumpkin and inulin. Results showed that the addition of pumpkin powder and inulin slightly increased acidity and increased viscosity of low-fat probiotic yogurts with increasing pumpkin powder and during cold storage period. Also, addition pumpkin powder and inulin was improved the survival of yoghurt cultural and Bifidobacterium lactis Bb-12 to 7.28 log cfu g−1 YPP2 comparison with plain (-) yogurt 6.33 log cfu g−1 after 14 days of storage period. The sensory evaluation revealed that there was statistically significant difference (P ≤ 0.05) between yoghurt with addition pumpkin powder and plain (-) yoghurt especially in color and flavor. So, according to present results addition of inulin and pumpkin powder can be used as a fat replacement to improve the texture profile analysis during the cold storage period, and to increase the yoghurt shelf life of low-fat yoghurt. Also, the addition of powder pumpkin (3%) and inulin (1%) to low- fat probiotic yogurts could be an alternative to incorporate the fat and texture improvers in dairy products. Therefore, adding pumpkin (3%) and inulin (1%) to low-fat yogurt is an alternative to adding artificial texture improvers and fat alternatives to low-fat probiotic yogurt as a new functional dairy food.
