Xylitol is a pentahydroxy sugar-alcohol which exists in a very low quantity in fruits and vegetables (plums, strawberries, cauliflower, and pumpkin). On commercial scale, xylitol can be produced by chemical and biotechnological processes. Chemical production is costly and extensive in purification steps. However, biotechnological method utilizes agricultural and forestry wastes which offer the possibilities of economic production of xylitol by reducing required energy. The precursor xylose is produced from agricultural biomass by chemical and enzymatic hydrolysis and can be converted to xylitol primarily by yeast strain. Hydrolysis under acidic condition is the more commonly used practice influenced by various process parameters. Various fermentation process inhibitors are produced during chemical hydrolysis that reduce xylitol production, a detoxification step is, therefore, necessary. Biotechnological xylitol production is an integral process of microbial species belonging to Candida genus which is influenced by various process parameters such as pH, temperature, time, nitrogen source, and yeast extract level. Xylitol has application and potential for food and pharmaceutical industries. It is a functional sweetener as it has prebiotic effects which can reduce blood glucose, triglyceride, and cholesterol level. This review describes recent research developments related to bioproduction of xylitol from agricultural wastes, application, health, and safety issues.

Cotton leaf curl disease (CLCuD), caused by cotton leaf curl Burewala virus (CLCuBV), has emerged as a major threat to cotton production in Pakistan. Resistance to CLCuBV was evaluated in cultivated and wild cotton genotypes representing six Gossypium species by visual symptom scoring and virus assessment using PCR tests. Considerable variation in responses was observed when using whitefly and graft transmission to inoculate Gossypium genotypes with CLCuBV in field and greenhouse experiments. Under field evaluation, all cultivated genotypes of Gossypium hirsutum and three genotypes of G. barbadense were susceptible. Eleven genotypes that represented six wild and cultivated Gossypium species were considered to be highly resistant as they were free from infection. Similar results were obtained when these genotypes were tested using whitefly transmission. To verify these findings, 132 cultivated and wild genotypes were tested by graft inoculation. All G. hirsutum genotypes (116 cultivated, 1 wild, 1 transgenic Coker‐312 and 1 non‐transgenic Coker‐312), three G. barbadense genotypes and one G. thurberi genotype were highly susceptible and exhibited symptoms 9–12 days after grafting. Four genotypes of G. arboreum and one genotype of G. anomalum did not express symptoms but had a detectable level of virus. One genotype of G. herbaceum and three wild genotypes of G. hirsutum showed mild symptoms (severity indexes of 1–2) and exhibited delayed disease development. These genotypes were classified as moderately resistant to resistant. Resistant genotypes that were identified in this study will be useful sources for exploitation of breeding programmes aimed at developing CLCuBV‐resistant varieties and increasing genetic diversity.

Extensive research has related the consumption of persimmon with the reduced risk of various diseases and particularly highlighted the presence of bioactive phenolic compounds for their therapeutic properties. Major phenolic compounds present in persimmon are ferulic acid,p-coumaric acid, and gallic acid.β-Cryptoxanthin, lycopene,β-carotene, zeaxanthin, and lutein are important carotenoids having antioxidant potential. They are important to prevent oxidation of low-density lipoproteins, safeguard beta cells of the pancreas, and reduce cardiovascular diseases, cancer, diabetes mellitus, and damage caused by chronic alcohol consumption. In this paper, the chemistry and health benefits of bioactive compounds present in persimmon are reviewed to encourage impending applications and to facilitate further research activities.

The effect of sodium chloride on the production of organic acids during ripening of buffalo milk Cheddar cheese at elevated temperature was evaluated. Buffalo milk Cheddar cheese was produced by adding sodium chloride at the rate of 0, 1 and 2% and stored for ripening at 4C and 12C for 120 days. The cheese was evaluated for organic acids i.e., lactic, acetic, citric, pyruvic, formic, butyric and maleic and mineral contents, including sodium, calcium and potassium at 60 and 120 days of ripening. The results showed that elevated ripening temperature accelerated the production of all organic acids and significantly increased their concentrations. However, during ripening, no effect on minerals profile was observed. High level of salt decreased the production of organic acids during ripening irrespective of ripening temperatures. Hence, it was concluded that elevated ripening temperature and enhanced sodium concentrations showed considerable effect on organic acids production. PRACTICAL APPLICATIONS Worldwide, Cheddar cheese is produced from cow's milk, but buffalo milk ranks at the top in Pakistan's milk production and, being nutritionally rich, is more suitable for cheese. Moreover, cheese ripening is a lengthy process and attempts to shorten the ripening time using a range of systems have had varying degrees of success. Organic acids are the major products of glycolysis during ripening and play an integral role in cheese quality. The addition of salt affects the cheese ripening and hence influences the production of organic acids. The project was designed with greater significance to determine the effect of sodium chloride on production of organic acids during accelerated ripening of buffalo milk Cheddar cheese. Practically, the project concluded that the optimal quantity of salt addition should be 1% in cheese manufacturing and recommended the ripening at 12C for 120 days in buffalo milk Cheddar cheese for better compositional profile.

The adverse health effects of dietary sodium demand the production of cheese with reduced salt content. The study was aimed to assess the effect of reducing the level of sodium chloride on the texture, flavor, and sensory qualities of Cheddar cheese. Cheddar cheese was manufactured from buffalo milk standardized at 4% fat level by adding sodium chloride at 2.5, 2.0, 1.5, 1.0, and 0.5% (wt/wt of the curd obtained). Cheese samples were ripened at 6 to 8 °C for 180 d and analyzed for chemical composition after 1 wk; for texture and proteolysis after 1, 60, 120, and 180 d; and for volatile flavor compounds and sensory quality after 180 d of ripening. Decreasing the salt level significantly reduced the salt-in-moisture and pH and increased the moisture-in-nonfat-substances and water activity. Cheese hardness, toughness, and crumbliness decreased but proteolysis increased considerably on reducing the sodium content and during cheese ripening. Lowering the salt levels appreciably enhanced the concentration of volatile compounds associated with flavor but negatively affected the sensory perception. We concluded that salt level in cheese can be successfully reduced to a great extent if proteolysis and development of off-flavors resulted by the growth of starter and nonstarter bacteria can be controlled.

Cheddar cheese is a biochemically dynamic product that undergoes significant changes during ripening. Freshly made curds of various cheese varieties have bland and largely similar flavors and aroma and, during ripening, flavoring compounds are produced that are characteristic of each variety. The biochemical changes occurring during ripening are grouped into primary events including glycolysis, lipolysis, and proteolysis followed by secondary biochemical changes such as metabolism of fatty acids and amino acids which are important for the production of secondary metabolites, including a number of compounds necessary for flavor development. A key feature of cheese manufacture is the metabolism of lactose to lactate by selected cultures of lactic acid bacteria. The rate and extent of acidification influence the initial texture of the curd by controlling the rate of demineralization. The degree of lipolysis in cheese depends on the variety of cheese and may vary from slight to extensive; however, proteolysis is the most complex of the primary events during cheese ripening, especially in Cheddar-type cheese.

Polyphenols are natural antioxidants and play a very vital role in inhibition of oxidative stress as induced by free radicals in the body. Apple and pomegranate peels are significant agro-industrial wastes. The waste could be utilized to extract polyphenols for processing various functional foods and nutraceuticals. An investigation was executed for extraction of polyphenols from apple and pomegranate peels by sonication and maceration. Three different polar solvents: methanol, ethanol, and acetone were used in the study at two different concentrations (50% and 75%). Yield (%), total polyphenolic content (TPC), total flavonoid content (TFC), and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay were performed. The extracts were then utilized in processing functional date bars with 2% and 3% concentrations. The results from the current study articulated that extraction from sonication yields higher quantity of polyphenols than that of maceration technique. The highest polyphenols were extracted at acetone 75% (44.71 mg GAE/g) in apple peel and at methanol 50% (72.21 mg GAE/g) in pomegranate peel. The results also revealed that pomegranate peel has higher polyphenols and greater radical scavenging activity as compared to apple peel. It was concluded that apple and pomegranate peel polyphenolic extract fortified date bars could be utilized as a preventive therapeutic agent against certain oxidative stress degenerative diseases.

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